ETOPS Explained
AN OVERVIEW OF EXTENDED OPERATIONS
BY BOEING COMMERCIAL AIRPLANES
Introduction
Extended Operations (ETOPS)
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This opening section of ETOPS Explained
„ Introduces ETOPS and examines its global success.
„ Defines the commercial aviation acronym ETOPS, which:
„ Previously stood for extended-range operations with two-engine
airplanes (see Section 1).
„ Today stands for extended operations following its redefinition
under the U.S. ETOPS rule of 2007 (see Section 2).
„ Discusses the many benefits of ETOPS.
„ Describes the structure of this informational BCA document, which
„ Has sections devoted to many different ETOPS issues and aspects,
and concludes with a helpful ETOPS Q&A.
„ Presents these sections formatted as stand-alone documents for
ease of use.
„ Includes supporting illustrations at the end of each section.
„ Concludes with the Table of Contents to ETOPS Explained and a
link to the MyBoeingFleet webpage where this document resides.
Overview
ETOPS is the enormously successful global program under which airlines
have long operated two-engine jetliners on routes that at some point take
the twinjet more than 60 minutes’ flight time (at single-engine cruise
speed) from an alternate airport. With passage of the U.S. ETOPS Rule
of 2007, ETOPS requirements today also apply to passenger jetliners with
three or four engines when they fly air routes that take them beyond 180
minutes (at one-engine-inoperative cruise speed) of an alternate airport.
ETOPS flying began over the North Atlantic in 1985. Today, long-range
twinjets operating under ETOPS rules fly extended nonstops in all regions
of the world, including services on the new polar routes that link Asia and
North America via the North Polar Region (fig. I-1).
As of December 2006, 5.5 million ETOPS twinjet flights had been logged,
and some 143 operators worldwide today fly about 1,700 more each day.
This vast industry experience shows that
„ ETOPS flying ranks among the safest and most reliable of all
flight operations.
„ ETOPS twinjets set the highest standard in long-range air travel.
„ Two-engine jetliners are well suited to long-haul and very-long-haul
services on routes with the potential for an extended diversion.
February 15, 2008
ETOPS Explained
Intro–1
Introduction Extended Operations (continued)
Two ETOPS
definitions
In the past, the ETOPS acronym stood for:
E xt en ded - R a ng e Ope rat i on s W i t h Tw o- Eng i ne A i rp la ne s
However, the U.S. ETOPS rule of 2007 has changed the legal definition
of ETOPS. For the first time, this regulatory updating applies the proven
benefits and protections of ETOPS to extended-diversion-time operations
involving three- and four-engine jet transports that carry passengers. In
light of this change, the ETOPS acronym has been simplified to denote:
Ext en ded O pe rat ions
This regulatory updating of ETOPS took effect on February 15, 2007.
Affected three- and four-engine operators have one year to comply with
its requirements if they wish to perform passenger operations on routes
that take the airplane beyond 180 minutes of an airport (see Section 2).
ETOPS benefits
air travelers
ETOPS benefits passengers through
„ More long-range nonstop services to a greater number of cities.
„ More total flights and greater choice in departure and arrival times.
„ Fewer flights required to reach one’s ultimate destination because
ETOPS allows direct services using smaller capacity airplanes.
„ Potential for lower ticket prices because twins cost less to operate.
„ Safety and reliability (see below and Section 3).
ETOPS also
benefits airlines
ETOPS benefits operators through
„ Increased passenger satisfaction.
„ Twinjet economics and efficiency.
„ Simplified long-haul operations.
„ Increased operational flexibility.
Almost all
twinjets are
ETOPS capable
„
„
„
More direct routings.
More reliable operations.
Reduced economic risk.
Except for twinjets strictly dedicated to short-haul use, virtually every
two-engine commercial transport built today is capable of ETOPS. All
current-production Boeing twins are ETOPS ready or capable. The new
787 Dreamliner has been designed from the outset for ETOPS like the 777
and Next-Generation 737 before it. Although the 767 was not designed
for ETOPS, it pioneered ETOPS and has logged more ETOPS flights than
all other airplane types combined. It is delivered ETOPS ready.
Among Boeing jetliners no longer in production, the single-aisle 757 is
a proven 180-minute-ETOPS workhorse. As for the short-haul 717, it
is certified for 75-minute ETOPS and is capable of 120-minute ETOPS
should operators ever wish to pursue this capability (fig. I-2).
February 15, 2008
ETOPS Explained
Intro–2
Introduction Extended Operations (continued)
ETOPS has
transformed
transatlantic
air travel
Before ETOPS debuted across the North Atlantic in 1985, this busiest of
all intercontinental air markets was the undisputed domain of three- and
four-engine jetliners like the DC-10, L-1011, and 747. Today, twinjets
like the 767 and 777 account for two-thirds of all flights in this market.
This dramatic transformation occurred because efficient twinjets with the
required range, seating capacities, and operating costs became available,
and so did ETOPS to allow their use in extended service. The result has
been strong market fragmentation as new transatlantic services continue
to proliferate between a rising number of city pairs (figs. I-3, I-4).
Before ETOPS, for example, passengers traveling from Atlanta to Milan
had to fly to New York, then to one of several European intercontinental
gateway airports, and finally from there to Milan. Today, twinjets directly
link these cities. Although ETOPS flying is performed around the globe,
the North Atlantic has the highest concentration of ETOPS activity. See
Section 5 for more information about transatlantic ETOPS.
Today ETOPS
is transforming
transpacific
air travel
Similar market fragmentation is occurring in the Pacific. The availability
of intermediate-capacity jets that can complement the 747-400 on verylong-haul routes—notably the 777—is broadening Pacific travel patterns.
Traditional hubs and gateways are being bypassed with direct services to
a growing number of cities on both sides of the ocean (figs. I-5, I-6, I-7).
Like the North Atlantic air market, the North Pacific market has a large
number of alternate airports should a two- , three- , or four-engine jetliner
ever need to divert because of a passenger medical emergency, fuel leak,
turbulence, decompression, cargo fire, or other issue. See Section 6 for
more information about transpacific ETOPS.
ETOPS and
aviation safety
February 15, 2008
Data collected since the beginning of the commercial jet age shows that
„ Two engines provide a safe level of propulsion redundancy.
„ On average, fewer than 1 out of every 100,000 ETOPS flights
experiences a diversion as a result of an engine shutdown
or failure during the ETOPS portion of flight (figs. I-8, I-9).
„ Four-engine jetliners have shown a higher rate of enginerelated fatal accidents than twinjets (fig. I-10).
„ Twinjets consistently demonstrate the lowest rate of hull loss
accidents as a result of propulsion-related events (fig. I-11).
„ No Western-built twinjet has ever suffered an accident as
a result of a loss of thrust in both engines from unrelated
causes (i.e., coincidental engine failures) as opposed to a
common cause (e.g., fuel mismanagement, volcanic ash).
(continued)
ETOPS Explained
Intro–3
Introduction Extended Operations (continued)
ETOPS and
aviation safety
(cont’d)
„
ETOPS has made aviation safer by allowing a proliferation of
direct air services using intermediate-capacity twinjets.
„ Direct travel reduces passenger exposure to the non-cruise phases
of flight in which 90% of fatal accidents occur (figs. I-12, I-13).
„ Flying direct reduces air traffic congestion because the busiest
hubs and airways are often bypassed.
See sections 3, 4, 8, and 12 for more information about ETOPS safety.
ETOPS lifts
the industry
Because ETOPS twinjet flying sets the highest standard for safe, reliable
flight operations, the global aviation community is collaborating on many
fronts to apply ETOPS-pioneered “best practices” more broadly in order
to lift the global industry to a higher and more uniform standard.
The U.S. ETOPS rule of 2007 is the first of these rulemaking activities to
reach fruition. Enacted by the Federal Aviation Administration (FAA) on
February 15, 2007, this rule
„ Updates and codifies in the U.S. federal aviation regulations the
reliability enhancements and operational protections of ETOPS.
„ Applies selected ETOPS requirements more broadly to also protect
the extended operation of three- and four-engine passenger jets.
See Section 2 for more information about the U.S. ETOPS rule of 2007.
Conclusions
First flown in 1985, ETOPS is a conservative, evolutionary program that
enhances safety, reliability, and efficiency during extended operations,
which are flight operations on routes that at times take the airplane far
from an alternate airport. Twinjets operated under ETOPS rules have
transformed air service patterns across the Atlantic Ocean, and are now
transforming them over the Pacific as well.
An enormously successful part of many airlines’ daily operations, ETOPS
benefits passengers and airlines alike. To passengers, it means greater
choice in flights, greater convenience in departure and arrival times, and
a higher likelihood that flights will be direct and on-time. To airlines,
ETOPS means greater profitability and flexibility, because it makes the
superior efficiency and reliability of twinjets available on routes that were
once the exclusive domain of 3- and 4-engine jetliners (see Section 3).
Today, the FAA ETOPS rule of 2007 applies the reliability enhancements
and operational protections of ETOPS more broadly to also embrace the
extended operation of passenger jetliners with three or four engines (see
Section 2). Except for regional jets and three- or four-engine freighters,
all commercial jets either are or will soon be delivered ETOPS capable.
February 15, 2008
ETOPS Explained
Intro–4
Introduction Extended Operations (continued)
About
ETOPS
Explained
This section has introduced ETOPS Explained, an illustrated Boeing
Commercial Airplanes informational publication that
„ Describes the evolution of ETOPS including key program
milestones (see Section 1).
„ Explains the broadening and redefinition of ETOPS that effect
with the U.S. ETOPS rule of 2007 (see Section 2).
„ Examines many different issues and aspects of ETOPS (see the
Table of Contents immediately below).
„ Provides this information in individual sections formatted as
individual “stand alone” documents to facilitate
„ Initial learning (clear presentation with supporting illustrations).
„ Quick-reference use (left-hand labels and other “nav aids”).
„ Is periodically updated and includes helpful links for more information.
Table of
contents
Section
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Appendix
MyBoeingFleet
Title
ETOPS Historical Overview
The U.S. ETOPS Rule of 2007
Twin-Engine ETOPS Experience
Three- and Four-Engine Airplanes and ETOPS
ETOPS Across the Atlantic
ETOPS Across the Pacific
Polar Flying and ETOPS
Airliner Diversions
Boeing ETOPS Twinjet Experience
Boeing 777 Outstation Engine Change Experience
ETOPS Flight Crew Training Requirements
ETOPS Maintenance and Configuration Requirements
ETOPS Economics
Additional Boeing and Engine Manufacturer Services
ETOPS Questions and Answers
All the sections of ETOPS Explained may be downloaded in PDF format
from MyBoeingFleet.com. If you are a Boeing person, you already have
access to MyBoeingFleet.com and can find this document on its home
page at Extended Operations / Resources / ETOPS Explained. If you are
instead with a Boeing customer airline or otherwise have external access
to MyBoeingFleet.com, you can access this document at:
https://www.myboeingfleet.com/ReverseProxy/Authentication.html
February 15, 2008
ETOPS Explained
Intro–5
Boeing ETOPS Operations Are Routine Worldwide*
Through September 2007
43,100 ETOPS flights per month
4,770,000 cumulative ETOPS flights
108 current ETOPS operators
* 737, 757, 767, and 777. Note: Besides scheduled commercial flights, this map also includes charter and some VIP ETOPS flights.
Figure I-1
767-ET-0020•
12-13-7-DH/KW/CJ
Many Operators are Utilizing
Boeing Twins' Extensive ETOPS Approvals
As of September 2007
Airplane
717
737
-200
-200
-3/4/500
-6/7/800
-900
-900ER
-200
757
-200 PF
-300
767
-200/300
-400
-200
777
-200ER
-200LR
-300
-300ER
Engine Type
BR715
JT8D
CFM56-3
CFM56-7
RB211-535C
RB211-535E4
RB211-535E4-B
PW2037/PW2040
RB211-535E4/E4-B
PW2037/PW2040
RB211-535E4/E4-B
PW2037/2040/2043
JT9D-7R4D/E
CF6-80A/A2
CF6-80C2 PMC
CF6-80C2 FADEC
PW4000
RB211-524H
CF6-80C2 FADEC
PW4000
GE90
Trent 800
PW4000
GE90
Trent 800
GE90-110B
PW4090
PW4098
Trent 800
GE90-115B
ETOPS Operators Count
FAA Type Design FAA Type Design
Total at any
Approval for
Approval for
180 min 207 min
level
120-minutes
180-minutes
75-minute approval granted May 2004
No 717 ETOPS operators
December
September
December
------------July
December
September
March
September
July
January
------May
August
May
March
April
March
July
-------------------------------------------------------------------
1985
1990
1998
1990
1986
1992
1990
1992
1990
1999
1985
1985
1988
1991
1990
1991
2000
------------September
April
April
July
July
September
April
September
April
January
June
April
April
April
May
July
March
July
May
October
October
March
February
April
February
June
April
May
March
1999
2001
2007
1990
1990
1992
1992
1992
1992
1999
2002
1990
1989
1989
1993
1993
1993
2000
1995
1996
1996
1997
1997
1997
2006
1998
2000
1998
2004
------10
0
0
0
13
0
4
0
0
0
1
4
4
7
19
15
2
2
1
3
2
5
9
8
1
0
1
3
10
Notes: * Some airlines operate more than one model, but are only counted once in the total.
The FAA approved the 777-200 and 777-200ER for 207 minute ETOPS over the North
Pacific in April 2000, later included the 777-300ER in Oct. 2004, and 777-200LR in Feb 2006.
Figure I-2
------------------------------------------------------------0
0
0
4
1
4
0
---------4
0
7
29
0
0
0
26
0
8
0
2
1
1
8
6
10
31
26
2
2
4
3
3
7
12
8
2
1
1
4
11
108*
Boeing
ETOPS
Operators
Twins Fly More than 3 Times as Many North Atlantic
Flights as 3- & 4-Engine Airplanes Combined
As of August 2007 OAG
2200
Twins
(737, 757, 767, 777,
A300, A310, A320,
A330)
2000
U.S. to
Europe:
weekly
nonstop
frequencies,
one way,
U.S. and
European
airlines
1800
1600
1400
1200
1000
Three- and four-engine airplanes
(DC-8, 707, 747, A340, L1011,
MD-11, DC-10 and Concorde)
800
600
400
200
0
'77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07
OAG-NA-All1
Figure I-3
Boeing Twins Have Changed the World
North Atlantic Air Traffic Patterns, U.S. Airlines - As of August 2007 OAG
1200
Boeing Twins
757, 767 and 777
1000
U.S. to
Europe:
weekly
800
non-stop
frequencies,
one way
600
400
Tri's L1011, MD11, and DC-10 Airbus Twins
A300, A310,
and A330
Quads - 747, DC-8,
707 and Concorde
200
0
'77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07
OAG-NA-US1
Figure I-4
Twins Dominate Trans-Pacific Flights
1992 - 2007
Twins
1200
1000
800
One-way
passenger
flights
per week
600
Quads and
Tri's
400
200
0
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
From August Official Airline Guide (OAG) each year. Non-stop passenger flights from America (North, Central or South, but
excluding Alaska) to Hawaii or Asia or Australia/New Zealand. And from Hawaii to Asia or Australia/New Zealand. Trans Pac
Figure I-5
Boeing Twins Are Changing The World
U.S. and Asian Airlines on North Pacific Routes -As of August 2007 OAG
500
747
400
U.S.
(including
Hawaii)
Across the
North Pacific
to Asia:
weekly
non-stop
frequencies,
one way
777
300
200
L1011, MD11,
and DC10
100
A340
A330
767
0
'92
'93
'94
'95
'96
'97
'98
'99
'00
'01
'02
'03
'04
'05
'06
'07
OAG-NP-All1
Figure I-6
Fragmentation And Market Growth Are Steadily Increasing
The Number of Trans-Pacific City Pairs Served
160
140
120
100
80
60
40
20
From August Official Airline Guide (OAG) each year. Non-stop passenger flights from America (North, Central or South,
but excluding Alaska) to Hawaii or Asia or Australia/New Zealand. And from Hawaii to Asia or Australia/New Zealand.
Figure I-7
Trans Pac - City Pairs
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
0
1985
Count of
Scheduled
City Pairs
each year
Most 777 Inflight Shutdowns (IFSDs) Occur
Outside the ETOPS Portion of Flight
June 1995 through September 2007
A summary of 82 IFSDs out of
1,069,900 777 ETOPS flights.
Only 9 (11%) occurred in the
ETOPS portion of flight. IFSD
rate on these 777 ETOPS
flights is approximately 0.004
per 1,000 engine flight hours.
ETOPS portion
0
Continue
0 Continue
0
Air Turnbacks
30
Air Turnbacks
Departure
(1,069,900 Flights)
20
Diversions
9
Diversions
Alternate
Airport
9
Diversions
Alternate
Airport
14
Continue
Destination
Less than one out of 100,000 ETOPS flights diverted from the ETOPS portion of flight due to engine IFSD.
777EIFSD-C.cvs
Figure I-8
Most 767 Inflight Shutdowns (IFSDs) Occur
Outside the ETOPS Portion of Flight
May 1985 through September 2007
A summary of 251 IFSD out of
2,867,700 767 ETOPS flights.
Only 31 (12%) occurred in the
ETOPS portion of flight. IFSD
rate on these 767 ETOPS
flights is approximately 0.006
per 1,000 engine flight hours.
ETOPS portion
3
Continue
2 Continue
3
Air Turnbacks
105
Air Turnbacks
Departure
(2,867,700 Flights)
50
Diversions
25
Diversions
Alternate
Airport
28
Diversions
Alternate
Airport
35
Continue
Destination
Less than one out of 100,000 ETOPS flights diverted from the ETOPS portion of flight due to engine IFSD.
767EIFSD-C.cvn
Figure I-9
Propulsion System Related Fatal Accidents
1959 - 2006
3
Twins
1-11
717
737-345
737NG
737-1,200
757
767
777
A300-600
A300-Early
A310
A318
A319
Fatal
Accidents 2
per 10
million
Airplane
Departures
A320
A321
A330
CRJ7/900
DC9
EMB 170/190
F100
F28
MD80
MD90
Mercure
SE-210
Tri's
Quads
727
DC10
L1011
MD11
Trident
146
146RJ
707/720
747-400
747-Early
880/990
A340
Comet
Concorde
DC8
VC-10
1
0
Total
Engine
propulsion Disintesystem
gration
related
accidents
Engine
plus
Crew
Crew
Error
Engine
Separation
Fuel Common
Exhaus- Cause
tion
Figure I-10
Human
Error
Reverser Unrelated UnconFuel Tank Cowl
trolled
Explosion Separamultiple
Fire
tion
propulsion
system
failure
Propulsion System Related Accidents
Hull Loss and Substantial Damage, 1959 - 2006
14
Twins
12
1-11
717
737-345
737NG
737-1,200
757
767
777
A300-600
A300-Early
A310
A318
A319
Accidents 10
per 10
million
8
Airplane
Departures
6
A320
A321
A330
CRJ7/900
DC9
EMB 170/190
F100
F28
MD80
MD90
Mercure
SE-210
Tri's
Quads
727
DC10
L1011
MD11
Trident
146
146RJ
707/720
747-400
747-Early
880/990
A340
Comet
Concorde
DC8
VC-10
4
2
0
Total
Engine
propulsion Disintesystem
gration
related
accidents
Engine
plus
Crew
Crew
Error
Fuel
Engine
Separa- Exhaustion
tion
Figure I-11
Common
Cause
Human
Error
Fuel
Cowl Reverser Unrelated UnconTank
Separatrolled
multiple
Explosion
tion
Fire
propulsion
system
failure
Few Accidents Happen in the Cruise Phase of Flight
Worldwide Commercial Jet Fleet
1959 - 2006
Initial
Total Percent Takeoff climb Climb Cruise Descent Approach Landing Taxi
Flight controls
12
17%
4
2
2
Powerplant or
Thrust reverser
20
28%
9
2
4
Hydraulics
4
6%
25
35%
1
1%
1
2
3%
1
6
8%
1
1%
71
100%
Landing Gear,
Brakes or Tires
Aux. Power Unit
(APU)
Fuel System
Electrical or
Instruments
Passenger
accomodations
Total
10
2
1
1
2
1
1
2
1
3
2
10
1
1
3
1
1
2
1
25
4
12
3
2
3
17
All airplane caused hull loss accidents on revenue flights in the worldwide commercial jet fleet 487 million flights over 48 years. Categorized by initial failure as cause.
Figure I-12
5
Few Fatal Accidents Happen in Cruise Flight
Cruise is a relatively benign phase of flight
Percent of fatal accidents in each phase of flight
31.5%
11.2%
Climb
(Flaps up)
11.2%
10.1%
Cruise
10.1%
Taxi
Load
Unload
Initial
Parked
Climb
Tow
7.9%
12.4%
Takeoff
11.2%
3%
14%
57%
4.5%
32.6%
Descent
4.5%
Initial
Approach
10.1%
Final
Approach
10.1%
Landing
22.5%
25%
1%
Exposure - percent of flight time estimated for a short, 1.5 hour flight
Fatal accidents by phase of flight in the worldwide commercial jet fleet in the 10 years from 1997 through 2006.
Few Accid in Cruise 2006.CNV
Figure I-13
Section 1
ETOPS Historical Overview
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This first section of ETOPS Explained
„ Describes the development of ETOPS, a collaborative industry /
government program under which two-engine, turbine-powered
airplanes have long been permitted since 1985 to fly air routes with
diversion times 1 that exceed 60 minutes.
„ Explains why, in the propeller era more than a half-century ago,
twin-engine airliners were restricted to routes that remain at all
times within 60 minutes’ flying time of an airport.
„ Shows how the shift to turbine propulsion many decades ago set
the stage for safe, reliable, and routine ETOPS twinjet operations.
„ Traces the evolution of ETOPS over time by briefly reviewing these
ETOPS program milestones:
„ 120-minute ETOPS (1985).
„ 180-minute ETOPS (1988).
„ ETOPS Simulation and Early ETOPS (early ’90s).
„ Accelerated ETOPS (1995).
„ 207-minute ETOPS (2000).
„ Concludes with a brief introduction to the U.S. ETOPS rule of 2007,
which is the subject of Section 2.
Note that this first section—like all the sections of ETOPS Explained—
is formatted for ease of use as a stand-alone document. Each addresses
a different aspect of ETOPS. See the Introduction for a brief overview
of ETOPS, key definitions, and this document’s full table of contents.
About
ETOPS
ETOPS is an enormously successful program under which the global
airline industry has long operated two-engine jetliners, or twinjets, on
routes that at some point take the airplane more than one hour’s flight
time, at single-engine cruise speed, from an alternate airport (fig. 1-1).
Flown since 1985, ETOPS ranks among the very safest and most reliable
of all flight operations. It is the state of the art in long-range air travel.
As of December 2006, airlines had performed about 5.5 million ETOPS
flights. See the Introduction section of this paper for a general
introduction to ETOPS.
1
Diversion time is the distance—measured in flight time at one-engine-inoperative cruise speed and altitude—that
the airplane is, or is permitted to be, from the nearest adequate airport.
February 15, 2008
ETOPS Explained
1–1
1. ETOPS Historical Overview (continued)
ETOPS
acronym
definitions
Before 2007, the commercial aviation acronym ETOPS stood for:
E xt en ded - R a ng e Ope rat i on s W i t h Tw o- Eng i ne A i rp la ne s
With passage of the ETOPS rule of 2007, however, the U.S. Federal
Aviation Administration (FAA) has revised this acronym to denote:
Ext en ded O pe rat ions
The reason for this legal redefinition is that the 2007 rulemaking applies
updated ETOPS more broadly to also embrace the extended operation of
passenger airplanes with three or four engines, not just twinjet extended
operations as was previously the case. The intent of this FAA regulatory
action is to lift the industry to a higher and more uniform standard.
This first section of ETOPS Explained offers a historical overview that
concludes with the January 2007 passage of the new FAA ETOPS rule.
Consequently, the focus of this section is the period when the first of the
above two definitions was in effect and ETOPS applied just to twinjets.
ETOPS
program
characteristics
Pioneered collaboratively by airlines, airframe and engine manufacturers,
and regulatory authorities around the world, the ETOPS program
„ Is inherently conservative.
„ Is driven by the analysis of facts and data.
„ Builds on evolutionary advances achieved in the capabilities
and reliability of airplanes and their propulsion systems.
„ Has profoundly transformed global air service patterns.
If it weren’t for ETOPS, airlines and the traveling public would not have
been able to benefit from the leading safety, reliability, and efficiency of
long-range twinjets (see Section 3) on extended-diversion-time air routes.
The reason is a longstanding operating restriction on two-engine airliners
that is informally known as the 60-minute rule.
About the
60-minute rule
In 1953, the United States enacted a regulation that prohibits two- and
three-engine airliners from flying more than 60 minutes (at one-engineinoperative flying speed) from an airport unless authorized to do so. In
1964, the FAA exempted three-engine jetliners from this 60-minute rule,
which subsequently applied just to twinjets.
Formalized in Part 121 of the U.S. Federal Aviation Regulations, this
restriction remains in effect today. However, the specific requirements
of regulation 14 CFR 121.161 have changed significantly with passage
of the U.S. ETOPS rule of 2007 as described in the next section.
February 15, 2008
ETOPS Explained
1–2
1. ETOPS Historical Overview (continued)
Technology
rendered this
rule outdated
When the 60-minute rule was enacted in 1953, it was the appropriate
response to the limited reliability of the piston engines that powered the
world airliner fleet in the decade after World War II. The intent of this
operating restriction was to ban two-engine propeller airliners—like the
Douglas DC-3—from long overwater routes that, during the propeller era,
were more safely served by four-engine types such as the Douglas DC-6,
Lockheed Constellation, or Boeing Stratocruiser.
Since 1953, enormous strides in flight-related technologies have vastly
improved the reliability and robustness of virtually every airplane system.
Starting in the late 1950s, for example, the industry converted to turbine
propulsion in a rapid transition that yielded an immediate quantum leap
in engine reliability. Subsequently, high-bypass-ratio turbofan engines,
or modern fanjets, were introduced and successively improved, providing
further reliability gains in what is one of commercial aviation’s most
dramatic ongoing trends.
This technological progress has fundamentally transformed commercial
aviation since the 60-minute rule was enacted. For example:
„ Current-generation turbofan engines are at least 100 times more
reliable than the large piston aircraft engines of the 1950s.
„ The propulsion-related accident rate of the late-1950s piston airliner
fleet was 100 times worse than that of today’s world jetliner fleet.
As with all regulations rendered obsolete by time and technology, the
60-minute rule required reconsideration. The result would be the ETOPS
program. To this day, non-ETOPS-approved twinjets remain restricted by
regulation to routes remaining within one hour of an airport.
About piston
aero engines
A 12-hp piston engine powered the Wright brothers’ Flyer in 1903. Piston
technology reached its zenith during World War II with the development
of huge, enormously complex power plants generating well over 3,000 hp.
The Boeing 377 Stratocruiser of 1949—Boeing’s last propeller airliner—
had four Pratt & Whitney R-4360 Double Wasp engines, the largest piston
engines ever used on an airplane. Generating 3,500 hp each, those radial
power plants were about eight times less reliable than the 1,200 hp radial
piston engines that powered the DC-3 (fig. 1-2).
Attesting to the reliability-compromising complexity of big radial engines,
Stratocruiser crews (pilot, copilot, and flight engineer) had to manage four
different sets of controls just to change power settings (throttle, mixture,
propeller setting, and turbo boost). In turn, Stratocruiser mechanics had
to maintain 112 high-compression cylinders, change 224 spark plugs, and
keep four large, complex constant-speed propellers working properly.
February 15, 2008
ETOPS Explained
1–3
1. ETOPS Historical Overview (continued)
About piston
aero engines
(cont’d)
The airline industry heaved a collective sigh of relief when the piston era
gave way to the commercial jet age. The reason is that turbine engines
are fundamentally simple and feature continuous combustion and smooth
rotation, in contrast to piston reciprocating engines, with their back-andforth stresses and individual explosions within cylinders.
Engine
reliability—
then and now
A half-century ago, long-range airliners had four engines for safety. The
reason was the limited reliability of piston engines and propellers.
“During my last year of flying props, I had no fewer
than 13 engine failures or shutdowns. It was a
relief to switch to jets!”
—Capt. Walt Gunn, TWA senior 747 pilot (ret.)
talking about flying Lockheed Constellations.
The above quote suggests how common propulsion failures were, back in
the propeller era. Further complicating matters:
„ Propeller problems often also necessitated engine shutdowns
(e.g., pitch control mechanism failure, out-of-balance condition).
„ The more powerful the piston engine, the worse its reliability.
In contrast:
„ Airline pilots starting out today have a good expectation of never
experiencing an engine failure their entire careers (fig. 1-3).
„ With turbine power, engine size (i.e., thrust rating) does not affect
reliability—small or large, the overall reliability of a fanjet engine
depends largely on how recent it is in terms of baseline technology.
Origins
of ETOPS
By the 1970s, all this technological progress had set the stage for safely
exceeding the 60-minute operating restriction with two-engine turbinepowered airplanes. Consequently, the international aviation regulatory
authorities, airframe and engine manufacturers, and pilot and passenger
associations initiated discussions in 1983 aimed at updating the existing
regulatory oversight and reconciling it with a new generation of twinjets
powered by enormously reliable high-bypass-ratio turbofan engines.
At that time, the Boeing 757 and 767 had recently entered service and the
Airbus A310 was under development. Therefore, these global discussions
focused in particular on the suitability of these new twin-engine transports
to operations on long overwater and other routes with the potential for an
extended-duration airplane diversion to an alternate airport.
The result of this global collaboration was the ETOPS program, whose
evolution is the focus of this section of ETOPS Explained.
February 15, 2008
ETOPS Explained
1–4
1. ETOPS Historical Overview (continued)
The 120-minute
ETOPS rule
In 1985, the FAA published Advisory Circular (AC) 120-42. Known as
the 120-minute ETOPS rule, this advisory document established the basis
under which twinjets could safely and routinely exceed the 60-minute
operating restriction imposed on two-engine airliners in 1953.
Operators who met the 120-minute ETOPS rule’s stringent requirements
were permitted to fly their modern twinjets on routes taking them up to 2
hours from an airport. A Boeing 767 crossing the Atlantic made the first
ETOPS flight in 1985. Since then, operators worldwide have performed
about 5.5 million ETOPS flights.
Note: Because Advisory Circulars recommend but do not mandate,
the 120-minute ETOPS rule was technically not a “rule” in the literal
sense of the word. In its application and effect, however, it served
as a de facto rule. The same was true of the 180-minute ETOPS rule
of 1988, which is described below in this section.
120-minute
ETOPS
requirements
The 120-minute ETOPS rule addressed the following:
1. Type design—the proposed airframe-engine combination was required
to have all specified 120-minute-diversion safety enhancements, and
the engine type was required to have
„ Amassed 250,000 total fleet engine flight-hours of experience,
a significant portion with the candidate airplane.
„ Achieved a reliability rate of approximately 0.05 in-flight shutdowns (IFSD) per 1,000 engine flight-hours on the world fleet.
2. Operational approval—the airline applying for 120-minute ETOPS
authorization was required to
„ Demonstrate 12 consecutive months of acceptable operation
with the proposed airframe-engine combination.
„ Implement ETOPS maintenance and dispatch procedures.
The 180-minute
ETOPS rule
In 1988, following three years of very successful ETOPS experience, the
FAA modified Advisory Circular AC 120-42 as AC 120-42A (fig. 1-4).
Known as the 180-minute ETOPS rule, this revised AC laid the bases for
180-minute ETOPS.
Aviation authorities in France, the United Kingdom, and elsewhere have
incorporated similar provisions. For example, Information Leaflet 20 of
the European Joint Aviation Authority (JAA) / European Aviation Safety
Agency (EASA) provides for 180-minute ETOPS.
February 15, 2008
ETOPS Explained
1–5
1. ETOPS Historical Overview (continued)
The 180-minute
ETOPS rule
(cont’d)
Key benefits of this ETOPS rule extension have been that it
„ Makes available a broader selection of en route alternate airports.
„ Increases airline opportunity to plan flights optimally.
„ Lets flight crews plan for diversion to the most appropriate alternate
airport for that day and mission.
„ Allows twins to fly new routes, such as U.S. West Coast to Hawaii.
180-minute
ETOPS
requirements
As issued in 1988, the requirements for 180-minute ETOPS addressed the
following two areas:
1. Type design—the proposed airframe-engine combination should meet
all 180-minute diversion requirements, and the engine type should
„ Demonstrate a reliability rate of approximately 0.02 IFSDs
per 1,000 engine flight-hours on the world fleet.
2. Operational approval—the airline applying for authorization to fly
180-minute ETOPS
„ Should have completed 12 consecutive months of acceptable
120-minute ETOPS experience with the proposed airplane type
(airframe-engine combination).
Alternative
ETOPS
operational
approval
methods
As the above shows, the 120-minute and 180-minute ETOPS rules both
specified requirements by which operators could obtain approval to fly
ETOPS. Those were the initial ETOPS approval methods.
ETOPS
Simulation
ETOPS Simulation was developed specifically for airlines that required
180-minute ETOPS but could not satisfy the stated operational approval
requirement because they lacked experience with 120-minute ETOPS.
Provided for in Appendix 6 to the ETOPS regulatory advisory material
(AC 120-42A), ETOPS Simulation instead required that 1,000 successful
simulated ETOPS flights be completed on non-ETOPS routes.
As the industry gained more experience with extended twinjet operations,
however, alternative methods were introduced by which operators could
obtain ETOPS operational approvals. Described bellow, these alternative
methods are ETOPS Simulation and Accelerated ETOPS.
Note: The ETOPS Simulation approval method has been used just once.
Airlines generally prefer to obtain ETOPS operational approvals through
other methods, in particular Accelerated ETOPS (see below).
February 15, 2008
ETOPS Explained
1–6
1. ETOPS Historical Overview (continued)
Accelerated
ETOPS
The remaining alternative for obtaining ETOPS operational approvals is
Accelerated ETOPS, a method that exploits the process-oriented nature
of ETOPS. Initially provided for in Appendix 7 to the ETOPS advisory
material, this method reduces or eliminates the requirement for airlines
to demonstrate prior in-service experience before starting ETOPS flying.
In particular, Accelerated ETOPS
„ Recognizes past industry experience relative to ETOPS approval.
„ Changes the emphasis from having prior ETOPS experience to
establishing and validating proven ETOPS processes.
„ Allows airlines to obtain operational approvals for ETOPS of up
to 180 minutes at entry into service.
The FAA and JAA began using Accelerated ETOPS in 1995 following 10
years of highly successful ETOPS (fig. 1-5). This method requires airlines
to show their regulatory authority that they have all the required ETOPS
processes in place and have these processes validated. Once this is done,
operators can generally fly ETOPS from the start of revenue service.
Very widely used, Accelerated ETOPS is the preferred way for airlines to
obtain ETOPS operational approvals. The new ETOPS rule has codified
this method in the U.S. federal aviation regulations.
Early ETOPS
for airplane
programs
The 777 was the first twinjet designed from the outset for ETOPS. A key
goal of the 777 program was service readiness and reliability—including
180-minute ETOPS capability—before delivery of the first 777.
Known as Early ETOPS, this ambitious Boeing initiative of the early
1990s culminated in 777 ETOPS type design approval (for P&W engines)
being awarded on May 30, 1995, less than six weeks after the 777 won
FAA and JAA type certification and one week before it entered service.
Defining elements of this highly successful effort were:
„ Extensive customer involvement.
„ Design enhancements based on previous ETOPS and non-ETOPS
operational experience.
„ Exhaustive ground and flight testing.
„ Airline operational-support products.
„ Regulatory participation and scrutiny.
In this way, the 777 program successfully paved the way for subsequent
Boeing airplane programs. The U.S. ETOPS rule of 2007 formalizes
Early ETOPS design, analysis, and test features in the U.S. regulations.
Boeing has designed both the all-new 787 Dreamliner twinjet and the
747-8, a major derivative of the four-engine 747, for early ETOPS.
February 15, 2008
ETOPS Explained
1–7
1. ETOPS Historical Overview (continued)
207-minute
ETOPS
In 2000, a 15-percent operational extension beyond 180-minute ETOPS
became available on a limited basis. Known as 207-minute ETOPS, this
maximum diversion authority
„ Can be used on existing 180-minute ETOPS routes but cannot
be used to pioneer new routes.
„ Was initially available just to 777 operators flying North Pacific
routes on a flight-by-flight exception basis.
„ Is today also being flown by a 777 operator in another region, and
will probably be available on other airplane types such as the 767.
Precedent for 207-minute ETOPS was indirectly set by the 120-minute
rule (AC 120-42) of 1985, which provided for a 15-percent operational
extension to 138 minutes. When the 180-minute ETOPS rule (AC 12042A) of 1988 took effect, it failed to include a similar provision. After
more than a decade of highly successful ETOPS, however, the industry
in 1999 requested a similar 15-percent operational extension beyond 180
minutes for a total diversion authority of 207 minutes. Following review
and resolution of all received public comments, the FAA approved 207minute ETOPS in March 2000. This 207-minute diversion authority
„ Allows 777 operators to fly the most efficient transpacific routes.
„ Enhances flexibility by giving flight crews more alternate airports
to choose from in the event that a diversion becomes necessary.
„ Results in flights being closer to alternate airports in most instances.
Continuing
evolution
The latest development in this continuing evolution of ETOPS is the U.S.
ETOPS rule of 2007, which came into effect on February 15, 2007. This
rulemaking brought big changes to ETOPS. Specifically, it
„ Implements updated requirements based on the analysis of a vast
amount of enormously successful ETOPS experience by operators.
„ Applies many of the proven protections of ETOPS to further enhance
the extended operation of three- and four-engine passenger jetliners.
„ Codifies ETOPS for the first time directly in the U.S. federal aviation
regulations as befits such wide-scale flight operations.
Although this rule applies to the extended operation of both twinjets and
three- and four-engine passenger jetliners, the threshold at which ETOPS
requirements apply differs for twinjets versus tris and quads. For twins,
ETOPS applies—as was formerly the case—on routes that at some point
take the airplane beyond 60 minutes (at single-engine cruise speed) of an
airport. For jets with more than two engines, ETOPS applies on routes
that take the airplane beyond 180 minutes (at one-engine-inoperative
cruise speed) of an airport (fig. 1-6). See this document’s next section
for a detailed look at the ETOPS rule of 2007 and its requirements.
February 15, 2008
ETOPS Explained
1–8
1. ETOPS Historical Overview (continued)
Conclusions
ETOPS is a conservative, evolutionary program that lets operators fly
approved twinjets on routes that at some point take the airplane beyond
60 minutes of an alternate airport. This proven regulatory framework lets
twin-engine, turbine-powered airplanes to safely and routinely exceed a
60-minute operating restriction imposed on two-engine airliners in 1953.
Known as the 60-minute rule, that operating restriction remains in effect
today for non-ETOPS-approved twinjets.
First flown in 1985, ETOPS has been enormously successful. Airlines
worldwide have logged about 5.5 million ETOPS twinjet flights. Every
day some 143 operators around the globe perform about 1,700 more.
This section of ETOPS Explained has shown that
„ Technological progress set the stage for ETOPS.
„ ETOPS is a conservative, evolutionary program based on
the analysis of facts and data (see also the Introduction).
„ ETOPS lets airlines and the traveling public benefit from the
safety, reliability, and efficiency of long-range twinjets on
extended-diversion-time air routes (see also Section 3).
On February 15, 2007, the FAA enacted a new ETOPS rule that codifies
and implements updated ETOPS requirements more broadly. This latest
ETOPS updating is the subject of the next section of ETOPS Explained.
February 15, 2008
ETOPS Explained
1–9
ETOPS
Extended
Operations
Without ETOPS, FAR 121.161 limits 2–engine airplanes
to routes that remain within 1 hour flying time from an
airport, and passenger airplanes with more than two
engines to routes within 3 hours from an airport.
*
60
*
60
Alternate
Alternate
*
*
60
*
180
60
Departure
ETOPS portion
of flight
Destination
Legend:
*
Airports
Distance traveled in the specified minutes at one engine inoperative cruise speed
ETOPS flight path
Non–ETOPS flight path
Figure 1-1
*
120
The Larger the Piston Engines,
the Lower the Reliability
10
8.94
Failure increase with engine size
8
6.84
6
(Fp) probability
of an engine
failure x 10 -4 4
4.97
3.36
2.03
2
1.00
0
1,000
(2,600)
1,500
(3,900)
2,000
(5,200)
2,500
(6,500)
3,000
(7,800)
3,500
(9,100)
(P) power extracted ~ Hp (thrust ~ lb)
M005C.004
05-06-99 db
Figure 1-2
Inflight Shutdown Rates of Todays Engines
Have Improved Significantly
0.9
0.8
0.7
Pre-1982 turbojets and turbofans
0.6
IFSD
per 1,000
0.5
Engine
Flight
0.4
Hours
0.3
0.2
1982-1988 turbofans
Modern Turbofans
0.1
0
0.10
1.00
10.0
Cumulative engine hours (millions)
TOTIFSD2.cvs
Figure 1-3
100
Advisory
Circular
U.S. Department
of Transportation
Federal Aviation
Administration
Subject: EXTENDED RANGE OPERATION
WITH TWO-ENGINE AIRPLANES
(ETOPS)
Date: 12/30/88
Initiated by: AFS-210/
ANM-270
AC No: 120-42A
Change:
1. PURPOSE. This advisory circular (AC) states an acceptable means, but not
the only means, for obtaining approval under FAR section 121.161 for two-engine
airplanes to operate over a route that contains a point farther than one hour flying time at
the normal one-engine inoperative cruise speed (in still air) from an adequate airport.
Specific criteria are included for deviation of 75 minutes, 120 minutes or 180 minutes
from an adequate airport.
2. CANCELLATION. AC 120-42, Extended Range Operation with
Two-Engine Airplanes dated June 6, 1985, is canceled.
3. RELATED FAR SECTIONS. Sections 21.3, 25.901, 25.903, 25.1309, 33.19,
33.75, 121.161, 121.197, 121.373, 121.565, and 121.703 of the Federal Aviation
Regulations (FAR).
4. DEFINITIONS.
a. Airport.
(1) Adequate. For the purpose of this AC, an adequate airport is an
airport certified as an FAR Part 139 airport or is found to be equivalent to FAR Part 139
safety requirements.
(2) Suitable. For the purpose of this AC, a suitable airport is an
adequate airport with weather reports, or forecasts, or any combination thereof, indicating
that the weather conditions are at or above operating minima, as specified in the
operation specifications and the field condition reports indicate that a safe landing can be
accomplished at the time of the intended operation.
b. Auxiliary Power Units (APU). A gas turbine engine intended for use as a
power source for driving generators, hydraulic pumps, and other airplane accessories and
equipment and/or to provide compressed air for airplane pneumatic systems.
(1) An essential APU installation provides the bleed air and/or
mechanical power necessary for the dispatch of a transport category airplane for
operating other than extended range operations with two-engine airplanes.
(2) An APU installation which is intended to serve as one of the three or
more independent alternating current (AC) electrical power sources required for extended
range operations provides the bleed air or mechanical power necessary for the safe flight
of a two-engine transport category airplane approved for extended range operation under
a deviation from FAR Section 121.161 and is designed and maintained to provide a level
of reliability necessary to perform its intended function.
PAR 1, 2, 3, 4
Page 1
Figure 1-4
ETOPS Operational Approval Option
Operational Approval Process
In-Service Method
12 months
of non-ETOPS
operations
(satisfactory
service
operation)
12 months
of 120-minute
ETOPS operations
ETOPS
approval
120 minutes
(satisfactory
service
operation)
ETOPS
approval
180 minutes
Airline introduction
into service of an
ETOPS airplane
Plan
submitted to
regulatory
authorities
ETOPS
processes
validated
Accelerated ETOPS
Operational Approval
ETOPS
approval
(up to 180
minutes)
M005N.002
05-21-99 db
Figure 1-5
When all airports are available, very few routes require more than 180-minutes,
which is the threshold of ETOPS for passenger airplanes with more than 2 engines.
78°N
Longyearbyen
Pituffik
Hatanga
Tiksi
Kangerlussuaq
Norlisk
Murmansk
Anadyr
Yakutsk
Fairbanks
Yellowknife
Reykjavik Stockholm
Iqaluit
Anchorage
Whitehorse
PetropavlovskBratsk
King Salmon
Kamcha
Goose Bay
Shemya
Churchill
Cold Bay
Khabarovsk
London
Gander
Seattle
Yuzhno-Sakhalinsk
Beijing
Sapporo
New York
Madrid
Seoul
Santa Maria
San Francisco
Tokyo
Moscow
Istanbul
Cairo
Magadan
Midway Is.
Delhi
Taipei
Bangkok
Male
Entebbe
Honolulu
Wake Is.
Guam
Hilo
Majuro
Medan
San Jose Cabo
Mexico City
Puerto Vallarta
Acapulco
San Jose
Tenerife
Dakar
Paramaribo
Monrovia
Diego Garcia
Jakarta
Harare
Johannesburg
Maputo
Durban
Mauritius
Nadi
Learmonth
Perth
Hobart
Sydney
Melbourne
Auckland
Easter Is.
Santiago
Georgetown
Luanda
Rio De Janeiro
Montevideo
Buenos Aires
Comodoro Rivadavia
Rio Gallegos
Christchurch
ETOPS Boundary
Recife
Hao Island
Rarotonga
Brisbane
Adelaide
60°S
Lima
Punta Arenas
747-400/PW4056 area of ETOPS applicability (based on 1520 nm)
Figure 1-6
Mount Pleasant
Libreville
Windhoek
Upington
Cape Town
Section 2
The U.S. ETOPS Rule of 2007
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Examines the ETOPS regulations enacted by the U.S. Federal
Aviation Administration (FAA) on February 15, 2007.
„ Explains the origin and reasons for this regulatory updating, which
„ Updates the requirements for extended-diversion-time flight
operations with two-engine, turbine-powered airplanes.
„ Also applies ETOPS for the first time to the extended-diversiontime operation of three- and four-engine passenger airplanes.
„ Summarizes the changes implemented by this new ETOPS rule by
examining its specific regulatory modifications and additions.
Note that this section (like all sections of ETOPS Explained) is formatted
for ease of use as a stand-alone document. Each addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS,
key definitions, and this multipart document’s table of contents.
Overview
On February 15, 2007, the FAA enacted comprehensive new regulations
governing extended operations (ETOPS), which are flight operations on
air routes that take an airplane far from an airport. This rulemaking has
codified FAA policy, industry best practices and recommendations, and
international standards designed to ensure that extended-diversion-time
flights continue to operate safely. To ease the transition for operators, this
rule specifies delayed compliance periods for many of its requirements.
The new ETOPS rule updates the requirements for two-engine extended
operations, provides for beyond-180-minute ETOPS diversion authority,
and allows operators of approved long-range twinjets to fly optimal flight
routings between virtually any two cities on earth. As before, ETOPS
applies when the twinjet flies beyond 60 minutes of an airport.
Under the rule, ETOPS also applies for the first time to the extendeddiversion-time operation of three- and four-engine passenger airplanes.
For these “tris and quads,” ETOPS applies when the transport jet flies
beyond 180 minutes of an adequate airport.
This rule lets airlines build further on the success of ETOPS, the state-ofthe-art in long-range air travel. ETOPS sets the standard for safe, reliable
flight operations. More than 5.5 million ETOPS twinjet flights have been
logged since 1985, and every day 143 operators perform 1,700 more.
February 15, 2008
ETOPS Explained
2–1
2. The U.S. ETOPS Rule of 2007 (continued)
Reminder:
ETOPS
definition
Previously, the ETOPS acronym stood for:
E xt en ded - r an ge oper at io ns w it h t wo - en g in e a i rp la ne s
Under the U.S. ETOPS rule of 2007, the ETOPS acronym
has been given a simpler legal definition:
Extended operations
A preclude
and protect
philosophy
Although ETOPS stands for extended operations, the alternative phrase
extended-diversion-time operations describes ETOPS more accurately.
These are flights conducted on routes that at some point take the airplane
far from an airport. Were the flight crew to elect to divert and fly to the
nearest alternate airport, a long diversion would be required.
The ETOPS program uses a proven preclude and protect philosophy to
mitigate the risks of extended diversions. This dual philosophy seeks to
preclude diversions through requirements that enhance the reliability and
robustness of airplanes, their engines, and their systems. Diversions can
never be entirely eliminated, however, since most result from passenger
illness, weather, and other factors unrelated to the functioning of the
airplane and its systems. Therefore, ETOPS also seeks to protect those
diversions that do occur through operational requirements such as airport
planning, a fuel reserve, a passenger-recovery plan, and so on.
Origin of this
U.S. rulemaking
By the latter 1990s, the global aviation industry recognized that:
ƒ The enormously successful ETOPS program had lifted air travel
to a higher plateau through operational protections, and through
airplane propulsion and systems reliability enhancements.
ƒ Continuing growth in airplane range capabilities over the decades
had resulted in flights increasingly traversing remote areas of the
world where an airplane is at times far from an alternate airport.
ƒ All airplanes flying extended-diversion-time routes contend with
similar operating challenges in terms of weather, terrain, and any
limitations in navigation and communications infrastructure.
ƒ The dual ETOPS philosophy of both precluding diversions, and
protecting those diversions that do occur, could benefit all flights
that find themselves a long distance from airports, not just those
performed with two-engine airplanes.
Responding to this growing awareness, the FAA in June 2000 asked the
global aviation community—working under the auspices of the Aviation
Rulemaking Advisory Committee (ARAC)—to review the ETOPS record
to date and recommend how ETOPS requirements should be updated,
standardized, and codified in the U.S. Code of Federal Regulations (CFR).
February 15, 2008
ETOPS Explained
2–2
2. The U.S. ETOPS Rule of 2007 (continued)
Reason for
regulatory
updatings
In aviation as elsewhere, regulation must stay abreast of changing times.
Even the most enlightened regulatory requirements and guidelines will
become burdensome if allowed to fall out of step with evolving trends
and advancing technology.
The FAA meets its responsibility to update aviation regulations through
the well proven, highly effective ARAC process. Over the years, ARACs
have successfully addressed a spectrum of issues.
About
the ARAC
Evolution of
the final rule
The ARAC is a U.S. framework that relies on international participation.
Within the ARAC, an ETOPS Working Group was chartered, gathering
together expert representatives from many of the world’s airlines, airframe
and engine manufacturers, regulatory authorities, pilots’ associations and
other interested non-governmental entities as listed here:
Airlines
All Nippon Airways; American Airlines; American Trans Air;
British Airways; Continental Airlines; Delta Air Lines; KLM
Royal Dutch Airlines; Northwest Airlines; Scandinavian Airlines
System; United Airlines; United Parcel Service; US Airways.
Associations
Air Transport Association; Association of European Airlines
(as represented by BA and KLM); European Association of
Aerospace Industries; General Aviation Manufacturers Association; International Civil Aviation Organization; International
Federation of Air Line Dispatchers’ Associations; National Air
Carriers Association; National Air Transportation Association;
National Business Aviation Association.
Manufacturers
Airbus Industrie; The Boeing Company; Bombardier; Cessna;
GE Aircraft Engines; Gulfstream; Pratt & Whitney; Rolls-Royce.
Pilots
associations
Air Line Pilots Association; Independent Association of Continental Pilots (now merged with ALPA); Allied Pilots Association;
Coalition of Airline Pilots Associations; International Federation
of Air Line Pilots’ Associations.
Regulators
U.S. Federal Aviation Administration; Joint Aviation Authorities
of Europe as represented by the U.K. Civil Aviation Authority
and the French Direction Générale de l’Aviation Civile; Transport Canada.
Other parties
Air Crash Victims Families Association.
The FAA received the ARAC ETOPS Working Group’s findings and
recommendations on December 16, 2002. After reviewing and modifying
these findings and recommendations as it deemed appropriate, the FAA
published the results in the U.S. Federal Register as a Notice of Proposed
Rulemaking (NPRM) on November 14, 2003. A standard 60-day review
period was provided for public comment.
In January 2004, this window was extended by another 60 days to an end
date of March 15 to ensure that all interested parties had sufficient time
February 15, 2008
ETOPS Explained
2–3
2. The U.S. ETOPS Rule of 2007 (continued)
Evolution of
the final rule
(cont’d)
to properly review and consider the 293-page NPRM document. During
this extended comment period, some 50 submissions were received from
regulatory agencies, operators, manufacturers, and interested nongovernmental associations around the world. The FAA reviewed these received
comments and acted on them as it deemed appropriate.
In addition to the FAA, the U.S. Department of Transportation (DOT)
and U.S. Office of Management and Budget (OMB) also reviewed and
modified this rulemaking. At the conclusion of this process, the final
ETOPS rule was published on January 16, 2007. This FAA rule took
effect 30 days later on February 15, 2007.
The Boeing
perspective
We at Boeing are proud to have worked with other stakeholders in the
global aviation community on this collaborative ARAC–FAA process,
which we believe makes long-distance flying safer and more reliable.
The U.S. ETOPS rule of 2007 validates and builds further on what has
been achieved around the world during more than two decades of highly
successful ETOPS twinjet flying.
Parallel
rulemaking
activities
In addition to the U.S. ETOPS rulemaking, the global aviation community
has been collaborating to address extended-diversion-time operations on
other fronts as well. Australia’s Civil Aviation Safety Authority (CASA)
enacted its new Extended Diversion Time Operations rule in July 2007.
The International Civil Aviation Organization (ICAO)—a branch of the
United Nations (UN)—is likewise pursuing updated extended operations
regulations, as is the European Aviation Safety Agency (EASA).
Boeing is an active participant in these past and continuing efforts, and
works toward the harmonization of aviation standards around the world.
Key insights
about the U.S.
ETOPS rule
The ETOPS rule of 2007
ƒ Establishes the design capabilities of each airplane type (i.e.,
airframe / engine combination) as the basis for determining
that airplane type’s maximum allowable diversion authority.
ƒ Defines allowable diversion authorizations and requirements for
the different regions of the world based on the overall operational
needs of each region.
ƒ Continues the proven ETOPS practice of actively improving engine
reliability by tracking twinjet ETOPS propulsion reliability levels
and reviewing operations to identify and correct common-cause
effects and systemic errors.
February 15, 2008
ETOPS Explained
2–4
2. The U.S. ETOPS Rule of 2007 (continued)
About
ETOPS
codification
The 2007 rulemaking has at last formalized ETOPS directly in the U.S.
aviation regulations as befits such large-scale operations. Prior to the
2007 rule, the ETOPS program—which then applied just to twinjets—
was established and administered by means of FAA Advisory Circulars
(AC), Policy Letters, and Special Conditions.
About
207-minute
ETOPS
Note that 207-minute ETOPS is not subject to the new requirements for
ETOPS beyond 180 minutes as introduced by the 2007 rule. Flown since
2000, 207-minute diversion authority (see Section 1) arose as a 15-percent
operational extension to existing 180-minute ETOPS authority for limited
use on a flight-by-flight exception basis. It thus predates the new rule and
remains subject to the requirements for 180-minute diversion authority.
The FAA permits 207-minute operation in the North Pacific Area, which
is the Pacific Ocean areas north of 40º North latitudes including NOPAC
ATS routes, and published Pacific Organized Track System (PACOTS)
tracks between Japan and North America.
To fly 207-minute ETOPS, the airplane’s cargo fire suppression system—
which typically is the most time-limited system—must have a minimum
capability of 222 minutes and the airplane must be SATCOM equipped.
About
Part 135
ETOPS
Also under the 2007 rule, ETOPS requirements apply for the first time
to commercial flights conducted under 14 CFR Part 135 (commuter and
on-demand operations). In Part 135 operations, ETOPS applies once the
route takes the airplane beyond 180 minutes of an airport. This ETOPS
threshold time applies to all Part 135 operations airplanes except those
performed by all-cargo airplanes with more than two engines, which are
exempted from ETOPS.
At the present time, the maximum ETOPS diversion authority available
to Part 135 operators is 240 minutes as computed assuming still air. In
general, ETOPS under Part 135 is very similar in terms of requirements
to ETOPS under Part 121 (scheduled air carrier operations).
The discussion in this and all sections of ETOPS Explained is confined
almost exclusively to flights conducted under 14 CFR Part 121.
Definition:
affected fleet
February 15, 2008
The term affected fleet refers to airplanes subject to the U.S. ETOPS rule
of 2007 because they are operated by carriers based in the United States.
Since other nations have the option of adopting this U.S. rule as the basis
of their own regulations governing extended-diversion-time operations,
the fleets of non-U.S-based air carriers may also become subject to some
or all of the updated ETOPS requirements described in this section.
ETOPS Explained
2–5
2. The U.S. ETOPS Rule of 2007 (continued)
Requirements
of the 2007
ETOPS rule
The below chart summarizes the specific changes implemented by this
2007 rulemaking. These changes are presented in terms of regulatory
additions or modifications relative to the previous “twinjet only” ETOPS
with which the industry has long familiarity.
After the chart, this section discusses these new or revised regulations in
greater detail, focusing on Part 121 flight operations. Also described are
two non-ETOPS provisions enacted within the 2007 ETOPS rulemaking.
ETOPS Rule of 2007
ETOPS
regulatory
changes
Operational
Approvals
Revised regulation 14 CFR 121.161 defines limitations on the distance
from an adequate airport that any transport airplane may be operated
without a specific ETOPS operational approval. For twinjets, ETOPS
applies when part of the route is more than 60 min from an airport.
For 3- and 4-engine passenger airplanes, ETOPS applies when part of
the route is more than 180 min from an airport.
Operators who currently fly 3- and 4-engine passenger airplanes on
routes with diversion times beyond 180 were given a 1-year delayed
compliance period to allow them to complete the ETOPS operational
approval process. This grace period ended Feb 15, 2008.
Operators of 3- and 4-engine freighters are exempted from the 2007
ETOPS rule. In contrast, ETOPS applies as before to twin-engine
freighters when they fly more than 60 min from an airport.
This regulation also requires specific polar operational approvals for all
flights traversing the North and South Polar areas. Within these areas,
this non-ETOPS polar requirement applies at all times to all airplanes,
passenger and cargo, regardless of actual diversion time or number of
engines. This provision codifies most elements of the preexisting FAA
polar policy, formalizing the requirements.
Definitions
Revised regulations 14 CFR 1.1 and 14 CFR 1.2 and new regulation
14 CFR 121.7 provide definitions of ETOPS-applicable terms to help
ensure proper understanding and compliance with the 2007 rule.
Communications
In addition to the preexisting communications requirements, new
regulations 14 CFR 121.99 and 121.122 require additional voice
communications for ETOPS beyond 180 min. The rule specifically
calls for rapid, reliable satellite-based voice communications of landline telephone quality, for example SATCOM voice.
An alternate form of communications must also be available in those
areas where voice communication is not possible or degraded. A
1-year delayed compliance period was provided. This requirement
also applies to 207-min operational approvals in the North Pacific area
of operation with immediate effect.
Dispatch
Revised regulation 14 CFR 121.624, 14 CFR 625, and 14 CFR 631
codify dispatch weather requirements.
(Continued)
February 15, 2008
ETOPS Explained
2–6
2. The U.S. ETOPS Rule of 2007 (continued)
ETOPS
regulatory
changes
(cont’d)
Fuel reserve
New regulation 14 CFR 121.646 codifies existing requirements for the
amount of reserve fuel to be carried to protect the airplane from a loss
of cabin pressure and / or engine failure resulting in a diversion to an
alternate airport at low altitude. This new rule includes a reduction in
this ETOPS fuel reserve requirement, which operators will welcome.
Maintenance
New regulation 14 CFR 121.374 codifies current ETOPS maintenance
practices and applies them to two-engine ETOPS. Three- and fourengine passenger planes that fly ETOPS are exempted.
Revised regulations 14 CFR 121.97 and 14 CFR 121.135 state that
Passenger
recovery plan operators who perform ETOPS on routes with diversion times beyond
180 min shall prepare and maintain recovery plans for each diversion
alternate airport identified for use in those operations. These plans
shall (1) ensure the well-being of stranded passengers and (2) provide
for their safe retrieval without undue delay. Carriers must also prepare
and maintain passenger recovery plans for all passenger operations
within the North and South Polar areas, regardless of actual diversion
time or how many engines the airplane has.
Time-limited
systems
1
For ETOPS up to 180 min (and 207 min ETOPS ) new regulation 14
CFR 121.633 maintains the existing standards of requiring time-limited
systems, such as the cargo fire suppression system, to have 15 min
additional capability beyond the maximum diversion time in still air.
Beyond 180 min, the new rule requires that the maximum diversion
times also include the effects of forecast winds and temperatures.
This regulation also requires that diversions for cargo fire suppression
be calculated at all-engines-operating cruise speed and altitude corrected for wind and temperature, whereas diversions for other timelimited systems be calculated at one-engine-inoperative cruise speed
and altitude corrected for wind and temperature. A 6-year delayed
compliance period gives operators time to bring their existing 3- and
4-engine fleets into ETOPS compliance for cargo fire suppression.
Airplane
performance
data
Revised regulation 14 CFR 121.135 codifies the existing requirement
that ETOPS operators have airplane performance data available to
flight crew and dispatchers to support their ETOPS operations.
Rescue and
fire fighting
New regulation 14 CFR 121.106 codifies the existing requirements for
rescue and fire-fighting services and equipment at all airports that are
designated as ETOPS alternate airports.
Training
Revised regulation 14 CFR 121.415 requires the training of crew
members and dispatchers in their specific roles and responsibilities
in the operator’s passenger recovery plans.
Type design
Regulations governing the design of transport-category airplanes (14
CFR Part 25) and engines (14 CFR Part 33) are revised to incorporate
ETOPS safety and reliability enhancements. For ETOPS beyond 180
min, new design requirements apply to all ETOPS aircraft, regardless of
the number of engines. An 8-year delayed compliance period is given
for currently certified airplanes, which must incorporate ETOPS design
changes if they continue to be in production past Feb 17, 2015.
(Continued)
1
As explained on p. 2–5, 207-minute ETOPS does not count as “beyond 180 minutes,” the threshold at which most
of the ETOPS rule of 2007’s new requirements apply. Flown since 2000 as a 15-percent operational extension to
180-minute ETOPS diversion authority, it is instead subject to the requirements for that pre-2007-rule authority.
February 15, 2008
ETOPS Explained
2–7
2. The U.S. ETOPS Rule of 2007 (continued)
ETOPS
regulatory
changes
(cont’d)
Type design
(cont’d)
In addition, new regulation 14 CFR 121.162 “grandfathers” the CMP
requirements for existing airframe / engine combinations that were
approved for up-to-180 minute ETOPS before Feb 15, 2007. For
airframe / engine combinations that were not ETOPS type-design
approved before Feb 15, 2007, a CMP must be developed that meets
the requirements of 14 CFR 25.3 or 14 CFR.25.1535.
These ETOPS regulatory changes are discussed below in greater detail.
Operational
approvals
Regulation 14 CFR 121.161 is revised to define the maximum flying time
that any airplane may be from an adequate airport. Together with the advisory material in AC 120-42B (see page 2–21), this updated regulation
ƒ Established the requirement for an FAA authorization to operate
two-engine, turbine-powered airplanes beyond 60 minutes flying
time, at single-engine cruise speed with no wind and in standard
conditions, of an adequate alternate airport.
ƒ Applied this same regulatory framework to the operation of turbinepowered passenger airplanes with more than two engines when they
fly routes that take them beyond 180 minutes, at one-engine-inoperative cruise speed with no wind and in standard conditions, of an
adequate alternate airport.
ƒ Established the operational approval requirements for all airplanes
on routes that traverse the North and South Polar areas.
ƒ Granted current 3 and 4 engine airplane operators a 1-year delayed
compliance period for obtaining their ETOPS operational approvals.
Similar
operational
requirements,
different
thresholds
All airplanes that fly beyond-180-minute ETOPS are subject to essentially
the same operational requirements (but not the same maintenance requirements, as described later in this section). However, the threshold at which
ETOPS become applicable differs for twinjets versus jetliners with three
or four engines.
For twinjets operating under 14 CFR Part 121, 2 ETOPS applies—as was
the case prior to the 2007 rule—on those air routes that at some point take
the airplane beyond 60 minutes of an airport. In contrast, for 14 CFR Part
121 operations by passenger jetliners with more than two engines, ETOPS
applies on those routes that at some point take the airplane beyond 180
minutes of an airport.
Note that three- and four-engine freighter operations are entirely exempted
from the 2007 ETOPS rule, in contrast to twinjet freighter operations.
2
Also called FAR Part 121, this is the part of the U.S. federal aviation regulations that governs the operation of
transport-category airplanes in scheduled commercial service.
February 15, 2008
ETOPS Explained
2–8
2. The U.S. ETOPS Rule of 2007 (continued)
ETOPS beyond
180 minutes
In the past, ETOPS was limited to 180 minutes (including 207-minute
ETOPS as explained). Under the 2007 rule, airlines gain flexibility since
the rule preserves current safety levels while letting operators fly beyond
180 minutes—potentially up to the capability of the airplane itself.
New diversionauthority basis
for twinjets
The ETOPS rule of 2007 makes the designed and certified capabilities of
each airplane type (i.e., airframe/engine combination) the basis by which
that type’s maximum-allowable diversion authority is established. This
revised basis, which sets the stage for longer diversion times in extended
operations, reflects the FAA’s recognition of the outstanding propulsion
reliability and safety demonstrated by long-range twinjets in more than
5.5 million ETOPS flights since 1985.
For twinjet ETOPS beyond 180 minutes, the 2007 rule requires greater
propulsion reliability than for ETOPS at or below 180 minutes. A new
type-design approval is also required for the airframe-engine combination,
and airlines must comply with additional operating standards.
About jets
with three or
four engines
Under the 2007 ETOPS rule, three- and four-engine passenger jetliners
will for the first time be subject to an operating restriction limiting them
to routes that remain within 180 minutes, at one-engine-inoperative cruise
speed, of an adequate airport. To exceed this restriction, airlines must
receive an ETOPS operational approval and use ETOPS airplanes except
as described in the following paragraphs.
In light of the enormously safe operating record of three- and four-engine
jet transports in long-haul service over the past half-century, the FAA has
exempted current-production tris and quads from having to obtain ETOPS
type-design certification for 8 years from the time that the 2007 rule took
effect. This “grace period” ends February 17, 2015.
As of this 2015 date, current-production airplanes with more than two
engines, if they are still in production, will have to incorporate ETOPS
design enhancements and secure ETOPS type-design certification if they
are to be used in extended-diversion-time passenger flight operations.
Three- and four-engine jet transports currently in service but no longer in
production are permanently “grandfathered.” This means that they may
continue to perform extended-diversion-time operations with no requirement for ETOPS type-design certification until phased out of service. Of
course, passenger versions of these tris and quads must comply with and
operate under ETOPS operational rules on routes that take them beyond
180 minutes of an airport. Freighter versions are exempted from ETOPS.
See this section’s ETOPS type-design discussion for more information.
February 15, 2008
ETOPS Explained
2–9
2. The U.S. ETOPS Rule of 2007 (continued)
Diversion
limits based
on needs of the
world’s regions
The ETOPS rule of 2007 defines the maximum-allowable diversion time
limit and requirements for the different regions of the world according to
the specific operational needs of each region (fig. 2–1). This basis offers
compliant operators of long-range airplanes, including twinjets, newfound
flexibility to fly optimal routings between virtually any two cities on earth
for which the approved airplane type has sufficient range. These different
maximum-allowable diversion times by region are:
ƒ ETOPS up to 180 minutes—the North Atlantic area of operations,
the Americas, Eurasia, and Austral-Asia under a continuation of the
approvals basis in effect prior to passage of the 2007 ETOPS rule.
ƒ ETOPS up to 207 minutes—the North Pacific area of operations
on a flight-by-flight exception basis under a continuation of the
180-minute diversion authority in effect before the 2007 rule.
ƒ ETOPS up to 240 minutes (flight-by-flight)—the Pacific Ocean
north of the Equator and the North Polar region on a flight-by-flight
exception basis.
ƒ ETOPS up to 240 minutes—the Pacific between the U.S. West coast
and Australia, New Zealand, and Polynesia; the Indian Ocean area;
and the oceanic area between Australia and South America.
ƒ ETOPS beyond 240 minutes—authorizations at different maximum
diversion times for the Pacific between the U.S. West coast and
Australia, New Zealand, and Polynesia; the Indian Ocean area; the
oceanic area between Australia and South America; and the South
Polar region.
The last three of these five ETOPS diversion-authorization categories are
new to ETOPS with the 2007 rule. They offer air carriers the opportunity
to fly properly configured and approved twinjets and other airplanes on
optimal flight routings between virtually any two cities on earth.
The propulsion-reliability requirements for beyond-180-minute ETOPS
are more stringent than for ETOPS up to and including 180 minutes. This
rigor ensures that existing safety levels are maintained wherever in the
world that ETOPS is flown. See Section 3 for a discussion of twinjet
safety under the 2007 rule’s increased diversion-time authorizations.
Very few routes in the world will require beyond-240-minute ETOPS
authorization, which is available between specified city pairs in southern
regions of the world. Beyond-240-minute ETOPS approvals will only be
granted to certificate holders who have been operating under 180-minuteor-greater ETOPS authority for at least 24 consecutive months, of which
at least 12 consecutive months were performed under 240-minute ETOPS
authority using the same airplane type (airframe / engine combination)
being proposed for beyond-240-minute ETOPS service.
February 15, 2008
ETOPS Explained
2–10
2. The U.S. ETOPS Rule of 2007 (continued)
Definitions
Many of the terms used in the new ETOPS rule are unique to this rule and
must be interpreted properly to ensure common understanding and proper
compliance. Regulations 14 CFR 1.1, 1.2 and 121.7 provide these needed
definitions. Of special importance are these airport-related definitions:
Adequate airport—the 2007 ETOPS rule revises this term’s definition to
mean an airport approved by the FAA for use by the operator because it
meets the landing performance requirements of 14 CFR 121.197 for the
airplane type being used, and either meets the requirements of 14 CFR
139, subpart D (or equivalent for non-US airports), excluding those that
apply to rescue and firefighting service; or is an active and operational
military airport. As before, the 2007 rule defines ETOPS areas of
operation by an airplane’s distance from the nearest adequate airport.
ETOPS Alternate airport—this ETOPS term denotes the airport used on
the day of the flight to define that flight’s dispatch limitations. ETOPS
Alternate airport thus replaces the former ETOPS term suitable airport,
which had this meaning under the original 1985 ETOPS guidance. Under
the 2007 rule, suitable airport is no longer an ETOPS term and suitable
itself has just its broad everyday meaning of “acceptable for the purpose.”
About
alternate
airports
To serve as an alternate, an airport must be
ƒ An adequate airport as defined above.
ƒ Listed in the air carrier’s operations specifications (“Ops Spec”)
document.
ƒ Designated in a dispatch or flight release for use in the event
of a diversion during the ETOPS phase of this flight.
ƒ Meet the public protection requirements, as appropriate, of
14 CFR 121.97.
ƒ Have a minimum rescue and firefighting services (RFFS) rating
of ICAO Category, as appropriate, as required by 14 CFR 121.106.
CFR 121.624 further states that, in order for an ETOPS alternate airport
to be listed in a dispatch or flight release, this alternate must
ƒ Have weather forecasts that meet ETOPS alternate minimum
requirements for the times of intended use from earliest to
latest possible landing time.
Communications
New regulations 14 CFR 121.99 (flag operations) and 14 CFR 121.122
(supplemental operations) require that all airplanes performing beyond180-minute ETOPS must have two communication systems, one of which
must be a satellite communication (SATCOM) voice system. As the FAA
(continued)
February 15, 2008
ETOPS Explained
2–11
2. The U.S. ETOPS Rule of 2007 (continued)
Communications
(cont’d)
observes, “the best way to assure clear and timely communication in
general is via voice communication.” Moreover, it notes that “there is
a significant safety benefit associated with an ETOPS flight having the
ability to communicate via a satellite-based voice system, especially for
those situations that occur while on long, remote ETOPS routes.” 3
This SATCOM voice-communications requirement ensures that ETOPS
flight crews can communicate emergency situations throughout their longrange flights and during extended diversions. An alternative means of
communication must also be available in the Polar areas in the event that
SATCOM does not work for any reason.
It should be noted that 777 operators flying 207-minute ETOPS across the
North Pacific may already meet this beyond-180-minute communications
requirement because the FAA required SATCOM for 207-minute ETOPS
when that diversion authority became available to operators in 2000.
Dispatch
Revised regulations 14 CFR 121.624 and 14 CFR 121.631 together codify
many existing ETOPS dispatch and flight release policies and implement
several changes that translate into improved payload performance for the
operator. The weather window during which the ETOPS alternate airport
must be at or above ETOPS minimums is reduced from the original 1985
ETOPS requirement of “plus and minus one hour before the earliest and
after the latest time of use.” Under the 2007 rule, this requirement reads
“from the earliest to the latest possible landing times.”
The 2007 rule also codifies the existing requirements to advise the flight
crew before they enter the ETOPS portion of flight of changes to weather
forecasts or other conditions that might affect their ability to make a safe
landing at the ETOPS alternate airport(s). As was previously the case,
weather-minimum requirements for ETOPS alternate airports revert to
normal landing minimums when the flight is underway.
New FAA Advisory Circular AC 120-42B, which addresses operational
aspects of the 2007 rule (see below), retains most of the current weather
minimums for ETOPS airports. However, it no longer requires separate
landing surfaces to utilize the two precision-approach minimums, and it
lists specific minimums for CAT II and CAT III precision approaches.
This AC also specifies relief for conditional weather forecast elements
less than TEMPO and PROB40.
In addition, 14 CFR 121.687 and 14 CFR 121.689 respectively codify
requirements to identify within the dispatch release and / or flight release
the ETOPS diversion time under which the flight is dispatched / released.
3
Notice 53057, U.S. Federal Register, vol. 72, no. 179, Sept. 17, 2007.
February 15, 2008
ETOPS Explained
2–12
2. The U.S. ETOPS Rule of 2007 (continued)
Fuel reserve
New regulation 14 CFR 121.646 codifies the existing ETOPS fuel reserve
requirements with noteworthy changes. The basic requirement remains
that all airplanes performing ETOPS must carry a fuel reserve sufficient
to allow diversion to an ETOPS alternate airport with the day’s forecast
winds and temperatures factored in. Three scenarios are addressed:
ƒ A rapid loss of cabin pressure followed by a descent to a safe
altitude as defined by oxygen availability (14 CFR 121.329 and
14 CFR 121.333 require supplemental oxygen for cabin pressure
altitudes above 10,000 feet).
ƒ A rapid loss of cabin pressure and a simultaneous engine failure
followed by a descent to a safe altitude as defined by oxygen
availability (14 CFR 121.329 and 14 CFR 121.333 require supplemental oxygen for pressure altitudes above 10,000 feet).
ƒ An engine failure, descent to one-engine-inoperative cruise altitude,
and diversion at one-engine-inoperative cruise speed.
Whichever of these scenarios requires the greatest amount of fuel defines
the total that must be available at the equal time point between alternate
airports. The first two scenarios are generally the most restrictive.
For calculating this ETOPS fuel reserve, the 2007 rule retains most of the
original 1985 requirements. They ensure sufficient fuel for an extended
low-altitude diversion followed by a descent to 1,500 feet at the alternate
airport, a 15-minute hold, and an approach and landing, and they allow for
in-flight use of the auxiliary power unit (APU) if required.
Based on ETOPS experience and the improvements achieved in en route
wind, weather, and icing forecasting capabilities, the FAA has dispensed
with some of the excessive conservatism in the original 1985 fuel-reserve
calculations. Under the 2007 updating, the ETOPS diversion scenario
no longer specifies a missed approach, a 5-percent factor on wind speed
replaces the original 5-percent fuel-burn penalty, and adjustments for
possible icing encounters during the diversion are significantly reduced.
The new icing requirements call for sufficient reserve to cover whichever
consumes more fuel: (1) ice accumulation on the unheated surfaces of the
airplane plus airframe and engine anti-ice for 10 percent of the time for
which icing is forecast; or (2) airframe and engine anti-ice alone for 100
percent of the time for which icing is forecast. For Boeing airplanes, this
second requirement will always be the more limiting condition.
Under the 2007 rule, passenger airplanes with more than two engines are
required for the first time to carry an ETOPS fuel reserve when they fly
beyond 180 minutes of an alternate en route airport. However, it should
be noted that many operators of three- and four-engine airplanes already
carry a decompression fuel reserve as a matter of internal airline policy.
February 15, 2008
ETOPS Explained
2–13
2. The U.S. ETOPS Rule of 2007 (continued)
Maintenance
New regulation 14 CFR 121.374 codifies the current ETOPS maintenance
practices. These practices have been proven to reduce airplane-related
diversions through disciplined maintenance procedures like engine condition monitoring, oil consumption monitoring, aggressive resolution of
identified reliability issues, and procedures that avoid human error during
the maintenance of airplane engines and systems.
Under the 2007 ETOPS rule, ETOPS maintenance requirements apply to
twinjets but not to three- or four-engine passenger jetliners when they fly
ETOPS. Because unscheduled landings at alternate airports can be costly
and disruptive events for airlines, however, some three- and four-engine
operators have voluntarily raised their maintenance standards to ETOPS
levels even though it is not required of them.
Passenger
recovery plan
Revised regulation 14 CFR 121.135 requires that for all ETOPS beyond
180 minutes (excluding 207-minute ETOPS), as well as for all passenger
operations in the North and South Polar areas, the air carrier must develop
a plan to ensure the well-being of passengers and crew members at each
approved en route alternate airport used in those operations.
An ETOPS passenger recovery plan must address the safety and comfort,
in terms of facilities and accommodations, of passengers and crew members stranded at the airport to which the flight diverted. This plan must
also provide for their prompt retrieval from the airport.
Time-limited
systems
Many onboard systems contribute to the overall safety of an airplane in
flight. Some of these onboard systems are limited in how long they can
operate or be effective. The cargo fire suppression system, the engine
lubrication systems, and possibly the cabin environmental control system
are examples of time-limited systems.
From the start of ETOPS in 1985, the maximum authorized diversion time
granted to an airplane type (i.e., airframe / engine combination) during the
ETOPS type-design approval process has been limited to the time that the
airplane’s cargo fire suppression system can continuously suppress a fire
minus 15 minutes. Other systems with inherent time or capacity limits
were also considered when determining maximum diversion authority.
The ETOPS rule of 2007
ƒ Codifies preexisting ETOPS time-limited-system requirements
for ETOPS up to and including 180 minutes.
ƒ Establishes additional operational requirements for ETOPS beyond
180 minutes as authorized under this new rule.
(continued)
February 15, 2008
ETOPS Explained
2–14
2. The U.S. ETOPS Rule of 2007 (continued)
Time-limited
systems
(cont’d)
ETOPS at or below 180 minutes—the rule states that the airplane must
have sufficient capacity for its cargo fire suppression system and next
most time-limited system to operate at least 15 minutes longer than the
maximum authorized diversion time. Still-air, standard-day conditions
are assumed. From an operational perspective, therefore, no additional
calculations are required beyond constraining the airplane’s flight track
to remain within the familiar “ETOPS circles” maps showing still-air
ETOPS areas of operation. These pre-2007-rule requirements, which
also apply to 207-minute ETOPS, are unchanged from before.
ETOPS beyond 180 minutes—for these operations by airplanes with two,
three, or four engines, the 2007 rule requires operators to plan differently
for diversions as a result of a cargo-compartment fire versus those relating
to other time-limited airplane systems:
ƒ Cargo fire suppression system—diversion planning is at all-enginesoperating altitude and cruise speed corrected for forecast winds and
temperatures. The diversion must not exceed the manufacturer’s
declared cargo fire system duration capability minus 15 minutes.
ƒ Other time-limited systems—diversion planning is at one-engineinoperative altitude and speed corrected for forecast winds and
temperatures. The planned diversion time may not exceed the
manufacturer’s declared system capability minus 15 minutes.
The reason that a concurrent engine failure is assumed for diversions
involving time-limited systems other than cargo fire suppression is the
possibility of related failures (for example, the worst-case possibility
that an uncontained engine failure might affect the functioning of other
airplane systems). In contrast, a cargo fire is logically unrelated to the
airplane’s engines, their functioning, or the possibility of a propulsion
failure, so a coincidental engine failure is not assumed in this event.
ETOPS
diversion
planning
Many in the global aviation community are acquainted with the familiar
“ETOPS circles” maps showing ETOPS areas of operation. These maps
assume still air and are drawn for different maximum authorized diversion
times (e.g, 120 minutes, 180 minutes). Requiring ETOPS routes to stay
within these overlapping circles has been an easy way to show the flight’s
dispatch limitation.
ETOPS circles can also be drawn for 240 minutes if the selected alternate
airports have RFFS 7 capability or can be supplemented to this level.
Because beyond-240-minute approvals are granted only between specific
city pairs, there is no need for ETOPS circles for these operations so long
as the required system capability checks are carried out during dispatch as
required for beyond-180-minute ETOPS flight operations.
(continued)
February 15, 2008
ETOPS Explained
2–15
2. The U.S. ETOPS Rule of 2007 (continued)
ETOPS
diversion
planning
(cont’d)
Another aspect of the pre-2007-rule ETOPS dispatch limitation was that
the actual diversion fuel requirements at the decompression altitude were
to be calculated from equal time points (ETP) between adequate airports.
The 2007 rule codifies these ETOPS dispatch-limitation elements and
specifies additional requirements for beyond-180-minute flight planning.
For beyond-180-minute ETOPS flight dispatch, at the ETP established
for the critical fuel calculation, a check is to be performed to ensure that
the planned diversion time to each ETOPS alternate airport, corrected for
forecast winds and temperature, is at least 15 minutes less than
ƒ The published time limit of the airplane’s cargo fire suppression
system as calculated at all-engine cruise speed and altitude.
ƒ The airplane’s next most time-limiting system, as calculated at
the operator’s approved one-engine-inoperative speed and altitude.
Six years
to comply
with cargo fire
suppression
requirements
The 2007 ETOPS rule grants three- and four-engine ETOPS operators
6 years to bring their existing fleets into compliance with the cargo fire
suppression system requirements. This delayed compliance period—
which ends February 15, 2013—serves to mitigate operator costs by
allowing the cargo fire suppression system upgrades to be performed
during regularly scheduled airplane heavy-maintenance intervals. It also
gives airplane manufacturers time to develop and certify this upgraded
system capability in their existing three- and four-engine airplanes.
This is another of the delayed compliance periods specified by the 2007
rule. See page 2–22 for a listing of these “grace periods.”
Airplane
performance
data
Revised regulation 14 CFR 121.135 codifies the previous requirement
for operators to provide their flight crews and dispatchers with airplane
performance data to support all phases of extended operations. This
readily available information must describe the specific performance
of the airplane in normal and non-normal situations, including those that
might arise during an extended-duration diversion to an alternate airport.
Rescue and
firefighting
In more than 5.5 million ETOPS twinjet flights around the world, there
has never been a landing accident following an extended diversion to an
alternate airport from the ETOPS phase of flight. However, the fact that
rescue and firefighting services (RFFS) have not been needed in the past
does not lessen the importance of this ETOPS operational protection.
(continued)
February 15, 2008
ETOPS Explained
2–16
2. The U.S. ETOPS Rule of 2007 (continued)
Rescue and
firefighting
(cont’d)
New regulation 14 CFR 121.106 codifies preexisting ETOPS rescue and
firefighting requirements for ETOPS alternate airports, and adopts the
standards of the International Civil Aviation Organization (ICAO) as the
basis for these ETOPS requirements. For all ETOPS, each airport listed
on the dispatch or flight release as an ETOPS alternate airport must have
RFFS capability equivalent to or higher than ICAO Category 4 4 which is
equivalent to the previous ETOPS requirement that alternate airports meet
14 CFR 139.315, Index A, for Airport Rescue and Fire Fighting (ARFF).
For ETOPS beyond 180 minutes, the 2007 rule imposes the added RFFS
requirement that the flight track remain within the operator’s maximum
diversion time (calculated at one-engine inoperative speed and altitude
assuming still air) from an adequate airport with an RFFS rating of at least
ICAO Category 7. These RFFS requirements are thus the same as those
for 207-minute ETOPS. Sufficient RFFS Category 7 and 4 airports are
already available to meet the 2007 rule’s RFFS requirement on virtually
all potential beyond-180-minute routes that Boeing airplanes will serve.
Finally, the 2007 ETOPS rule also codified a preexisting ETOPS policy
allowing an airport to be used as an ETOPS alternate even though it lacks
sufficient equipment or personnel to meet the specified RFFS rating. This
is only permitted where local municipal firefighting assets can be made
available—given 30 minutes’ notice while the diversion is in progress—
to temporarily bring the airfield up to the required ICAO standard. Prior
commitment is required that this supplemental RFFS will be available on
landing and will remain for as long as needed by the arriving flight.
Training
Revised regulation 14 CFR 121.415 was modified to require training for
crew members and dispatchers in their specific roles and responsibilities
in the passenger recovery plans for those alternate airports the operator
relies on for ETOPS.
Type design
The ETOPS rule of 2007 specifies changes to 14 CFR Parts 25 and 33,
which set U.S. airworthiness standards for the manufacture of commercial
jet transports and engines, respectively. This rule also specifies changes
to 14 CFR Part 21.4, which addresses ETOPS reporting requirements for
manufacturers. These regulatory changes codify ETOPS design-related
“best practices” that enhance safety and reliability. They set a higher and
more uniform type-design baseline that will ensure all long-range jetliner
designs approved for beyond-180-minute ETOPS maintain the same high
standards that have exemplified ETOPS experience since 1985.
(continued)
4
ICAO Annex 14, Volume 1, Aerodrome Design and Operations.
February 15, 2008
ETOPS Explained
2–17
2. The U.S. ETOPS Rule of 2007 (continued)
Type design
(cont’d)
These ETOPS regulatory changes
„ Codify existing ETOPS policies, practices, and special conditions
in a uniform set of design regulations.
„ Build further on existing fail-safe design standards to allow for typedesign approvals beyond the current 180-minute ETOPS diversion
authority limit.
„ Create the basis for ETOPS type-design approvals in new regulation
14 CFR 121.162, which
„ Affirms that current ETOPS type-design–approved airplane
types (airframe / engine combinations) may continue to be
operated on ETOPS routes without a new approval process.
„ Delineates the airworthiness standards that apply to airplane
types (airframe / engine combinations) that do not currently
have ETOPS type-design approvals before they may be used
in 14 CFR Part 121 ETOPS.
New or derivative long-range jetliners launched after the 2007 ETOPS
rule took effect must meet these updated type-design requirements, as
must any new or derivative engines developed to power them. Currently
produced three- or four-engine ETOPS airplanes must also meet them if
they remain in production past February 17, 2015, which is when an 8year delayed compliance period specified by the 2007 rule expires.
The first new
type-design
certifications
The first airplanes developed to the ETOPS rule of 2007’s updated typedesign requirements are the Boeing 787 Dreamliner twinjet and the fourengine Boeing 747-8 Intercontinental, the passenger version of the 747-8,
a major derivative of the 747. Although both these airplane programs
were launched before the rule took effect, Boeing is voluntarily certifying
them to the updated airworthiness standards.
About the
CMP document
Each ETOPS airplane type (i.e., airframe-engine combination) is required
to have a defining reference source called the Configuration, Maintenance
and Procedures (CMP) document. The ETOPS rule of 2007 defines it as
“a document approved by the FAA that contains minimum configuration,
operating, and maintenance requirements, hardware life-limits, and Master
Minimum Equipment List (MMEL) constraints necessary for an airplaneengine combination to meet ETOPS type design approval requirements.” 5
The CMP defines all the additional requirements associated with the typedesign approval of the airframe-engine combination. It lists configuration
and maintenance requirements for the approved diversion time permitted
for the airplane, and also any additional operational requirements.
5
U.S. Federal Register, Washington, DC, vol. 72, no. 9, January 16, 2007, p. 1871.
February 15, 2008
ETOPS Explained
2–18
2. The U.S. ETOPS Rule of 2007 (continued)
Non-ETOPS
provisions
Within the ETOPS Rule of 2007, the FAA has also addressed provisions
that are not ETOPS but relate to it:
Non-ETOPS Provisions in this Rulemaking
Polar
operations
Revised regulation 14 CFR 121.161, which authorizes ETOPS,
also addresses North and South Polar flight operations. Within
these regions, the polar area operational requirements apply at
all times to all airplanes. These requirements are in addition to
ETOPS if it is being performed.
Three- and fourengine airplane
decompression
fuel planning
New regulation 14 CFR 121.646, which specifies ETOPS fuelreserve requirements, also has a paragraph that requires all threeand four-engine airplanes to carry sufficient fuel to safely reach an
alternate airport in the event of decompression and diversion at low
altitude where range is significantly reduced.
Existing regulation 14 CFR 121.565, which states the requirement
Propulsionrelated airplane to land at the nearest suitable airport following an in-flight engine
failure or shutdown, remains substantively unchanged in the new
diversions
rule but is reworded for clarity.
These non-ETOPS regulatory changes are discussed below.
Polar
operations
The North and South Polar regions are defined as everything north of 78°
N latitude and south of 60° S latitude, respectively. Within these regions,
all airplanes—regardless of actual diversion time or number of engines—
must meet FAA polar operations requirements as authorized by revised
FAA regulation 14 CFR 121.161 and further described in Appendix P to
Part 121. Additional advisory material relating to polar flight operations
appears in AC 120-42B.
These polar-area operational requirements—which are in addition to any
ETOPS requirements—were first published as an FAA Policy Letter in
2001 and were previously known as the FAA polar policy. The 2007 rule
has codified this policy with only minor changes. This rule thus provides
a uniform process for operators seeking polar route authority.
Twinjets will require ETOPS for North Polar flight operations because
of their lower ETOPS threshold of 60 minutes from an adequate airport.
In contrast, airplanes with more than two engines will not normally need
ETOPS to operate within this region because of their higher 180-minute
ETOPS threshold.
Within the South Polar region, all airplanes will require ETOPS because
of the larger total area that it encompasses, the greater ratio of open water
to landmass, and the proportionately greater distances between its fewer
available alternate airports.
February 15, 2008
ETOPS Explained
2–19
2. The U.S. ETOPS Rule of 2007 (continued)
Specific polar
requirements
To operate within a polar region, an air carrier must
„ Have a special operational approval listed in its Operations
Specification document that spells out applicable policies
and procedures.
„ Identify in the Ops Spec document the en route alternate airports
on which these operations will rely.
„ Have current passenger recovery plans in place for these identified
diversion airports (all-cargo operators are of course exempted from
this requirement).
„ Implement a fuel freeze strategy and appropriate procedures.
„ Ensure adequate communications capability.
„ Provide training on solar radiation hazards and other challenges
unique to polar operations.
„ Implement a minimum equipment list (MEL) specific to these
operations.
„ Have at least two cold weather survival suits aboard to protect crew
members during outside activities at diversion airports where possible
extreme weather conditions might prevail. However, the FAA may
relieve operators from carrying these suits during summer months.
Three- and fourengine airplane
decompression
fuel planning
New regulation 14 CFR 121.646, which defines the ETOPS fuel reserve
requirements, also includes a non-ETOPS provision added by the FAA
to resolve a potential safety concern for airplanes with more than two
engines. Although U.S. regulations have long required that supplemental
oxygen be available in the event of a sudden loss of cabin pressure, they
had in the past not explicitly required three- and four-engine airplanes to
carry sufficient reserve fuel to ensure that an alternate airport could safely
be reached following a diversion at low altitude where fuel consumption
rises and range is reduced.
While many tri and quad operators routinely carry a depressurization fuel
reserve as a matter of internal policy, some operators were not specifying
this safety-enhancing fuel reserve. Consequently, the FAA has added
paragraph 14 CFR 121.646(a), which requires all three- and four-engine
jet transports (not just those that fly ETOPS) to carry a decompression
fuel reserve whenever they fly beyond 90 minutes of an adequate airport,
calculated at all-engine cruise altitude and speed.
Propulsionrelated airplane
diversions
Within this ETOPS rulemaking, the FAA has updated 14 CFR 121.565,
the regulation governing airplane diversion requirements in the event of
an in-flight engine failure (IFSD) or shutdown. While these propulsion(continued)
February 15, 2008
ETOPS Explained
2–20
2. The U.S. ETOPS Rule of 2007 (continued)
Propulsionrelated airplane
diversions
(cont’d)
failure requirements remain substantively unchanged, the regulation itself
has been reworded for clarity.
This revised regulation now states that, in the event of an engine IFSD or
failure, the pilot in command (PIC) of a twinjet must land at the nearest
suitable airport in terms of flight time. In contrast, airplanes with more
than two engines may proceed beyond the nearest suitable airport if the
PIC determines that so doing will not diminish the safety of the flight.
Because of past confusion as to what constitutes a suitable airport, FAA
Advisory Circular AC 120-42B offers additional guidance on the matter.
According to the AC, the following factors—all of which are consistent
with the ETOPS philosophy of protecting diversions—are among those
that may be relevant to determining whether an airport is suitable:
„ Airplane configuration, weight, systems status, and remaining fuel.
„ Wind and weather conditions en route at the diversion altitude.
„ Minimum altitudes en route to the diversion airport.
„ Fuel burn to the diversion airport.
„ Airport wind, weather, and surrounding terrain.
„ Runways available and their surface condition.
„ Available approach-navigation aids and lighting.
„ Available rescue and firefighting services.
„ Facilities for passenger and crew member disembarkation
and accommodations.
„ PIC’s familiarity with the airport.
„ Airport information provided to the PIC by the certificate holder.
Furthermore, to help ensure that safety is not compromised, this AC
guidance also lists those factors that the PIC of a twinjet with one engine
operative should not consider to be sufficient justification to fly beyond
the nearest suitable airport:
„ Sufficient fuel supply remaining to reach more distant airports.
„ Passenger accommodation beyond basic safety.
„ Availability of on-site maintenance and / or repair resources.
About the
rule-related
advisory
circulars
February 15, 2008
In addition to the ETOPS rule and its preamble, the FAA is issuing three
advisory circulars that offer additional guidance in terms of insights and
clarifications. These ACs address the rule’s requirements in three areas:
„ 14 CFR Part 121, Scheduled Air Carrier Operations.
„ 14 CFR Part 25, Airplane Design.
„ 14 CFR Part 33, Engine Design.
(continued)
ETOPS Explained
2–21
2. The U.S. ETOPS Rule of 2007 (continued)
Rule-related
advisory
circulars
(cont’d)
The FAA divided this additional 2007 rule guidance among three ACs
to avoid confusion over which requirements apply to airplane operators,
which to airplane manufacturers, and which to engine manufacturers.
AC 120-42B addresses the rule’s Part 121 or operational requirements.
Delayed
compliance
periods
The ETOPS rule of 2007 granted three- and four-engine operators with
existing extended-diversion-time flight operations that take the airplane
beyond 180 minutes of an airport one (1) year to comply with operational
and equipment changes resulting from this rule’s requirements. Operators
were thus given until February 15, 2008, to:
„ Install satellite voice communications (two-engine airplanes
approved for 207-minute ETOPS already meet this requirement).
„ Establish passenger recovery plans for the alternate airports.
„ Prepare and implement additional passenger-recovery crew training.
„ Obtain operational approval to fly ETOPS routes.
These existing three- and four-engine operators are also granted:
„ Six (6) years, ending February 15, 2013, before upgraded cargo fire
suppression systems must be installed.
„ Eight (8) years to obtain type-design approval for ETOPS (required
only if the current airplane type is still in production as of February
17, 2015) and to issue new CMPs if applicable.
Conclusions
The new U.S. ETOPS rule, which took effect February 15, 2007, updates
the requirements for twinjet extended operations, and it applies ETOPS
more broadly to also embrace the extended-diversion-time operation of
three- and four-engine passenger airplanes. For tris and quads, ETOPS
applies on routes that at some point take the airplane beyond 180 minutes
of an airport. For twins, ETOPS applies as before on routes that at some
point take the airplane beyond 60 minutes of an alternate airport.
The more stringent regulatory framework introduced by this rulemaking
ensures that existing safety is preserved while providing for beyond-180minute diversion authority. It offers compliant operators the newfound
flexibility to fly their approved twinjets and other airplanes on optimal
routings between virtually any two cities on earth.
This rule lets airlines build further on the enormous worldwide success
of ETOPS, the state-of-the-art in long-range air travel. ETOPS sets the
highest standard for safe, reliable flight operations. More than 5.5 million
ETOPS twinjet flights have been logged from 1985 to 2007 and every day
143 operators perform some 1,700 more.
(continued)
February 15, 2008
ETOPS Explained
2–22
2. The U.S. ETOPS Rule of 2007 (continued)
Conclusions
(cont’d)
The ETOPS rule of 2007 reflects the following facts:
„ The safety and reliability of two-engine jetliners today equals or
exceeds that of three- and four-engine jetliners (fig. 2–2).
„ All airplanes flying extended-diversion-time routes contend with the
same operating challenges in terms of weather, terrain, and possible
limitations in navigation and communication infrastructure.
„ Any airplane, regardless of how many engines it has, might someday
need to divert for reasons that could include passenger illness, smoke
in the cockpit, adverse winds, fuel leaks, turbulence, cargo fire, or a
significant system or engine failure.
„ The dual ETOPS philosophy of both precluding diversions and
protecting those that do occur benefits all extended-diversiontime passenger operations, not just twinjet extended operations.
This rulemaking ensures that air carriers performing ETOPS with twinjets
or three- or four-engine passenger jetliners have the requisite experience
and ability to maintain and operate these airplanes at the required level of
reliability and competence. To ease the transition for current three- and
four-engine operators, delayed compliance dates were specified for many
of the 2007 ETOPS rule’s requirements.
On the operational front, this rule ensures that suitable alternate en route
airports are available; that airplanes have sufficient reserve fuel to reach
these airports under even the most challenging circumstances; that rescue
and firefighting equipment will be there when a diverting airplane arrives;
and that operators flying routes with diversion times beyond 180 minutes
have planned for the safety, comfort, and prompt retrieval of passengers
stranded at these remote airports.
On the design front, this new rule has codified “best practices” that will
continue to reduce the rate of airplane propulsion and system failures that
can cause a diversion. Type-design requirements in this rulemaking will
also ensure that all time-limited airplane systems will support worst-case
scenarios by remaining continuously available throughout a diversion to
the limit of that flight’s maximum ETOPS diversion authority.
In addition to this U.S. ETOPS rule, the global aviation community is
collaborating to update the requirements for extended-diversion-time
flight operations on other fronts as well. Australia’s Civil Aviation Safety
Authority (CASA) enacted its new Extended Diversion Time Operations
rule in July 2007. The International Civil Aviation Organization (ICAO),
European Joint Aviation Authorities (JAA)/European Aviation Safety
Agency (EASA), and other parties are likewise pursuing similar updates
of extended operations regulations. Boeing participates actively in such
efforts and supports the harmonization of aviation standards worldwide.
February 15, 2008
ETOPS Explained
2–23
Extended Operations for Twins
Maximum Time Authorized for Various Regions Reflect Real World Needs
78°N
180-minutes
207-minutes – Flight-by-flight
Pacific Ocean areas north of 40°N
latitude including NOPAC ATS routes
and published PACOTS (Pacific
Organized Track System) tracks
between Japan and North America
Equator
60°S
Figure 2-1
240-minutes – Flight-by-flight
North polar area and Pacific ocean
north of the equator
ETOPS up to & Beyond 240 minutes
Pacific Oceanic area between the U.S.
West coast and Australia, New
Zealand, and Polynesia; South Atlantic
oceanic area; Indian Ocean area;
oceanic area between Australia and
South America; (and South Polar area
as only beyond 240-minutes)
Hull Loss Accident Rates - Twin vs Quad
10 year rolling Average
3.5
Western built jet engine airplanes over 60,000 lbs gross weight.
3
2.5
Hull Loss
Accidents
per Million
Departures
Quads
2
1.5
1
Twins
0.5
0
1975
1980
1985
1990
Figure 2-2
1995
2000
2005
Section 3
Twin-Engine ETOPS Experience
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Describes the 60-minute rule, a twin-engine operating restriction
that was enacted in 1953, and examines the intent behind this rule.
„ Shows how and why that piston-era regulation fell out of date.
„ Describes the origins and history of twinjet operations, and briefly
reviews the factual record of these today-predominant operations.
„ Places into perspective the relative safety of different categories of
commercial jet transports (i.e., twinjets, trijets, and four-engine jets).
„ Shows why and how twinjet design requirements ensure at least
equivalent safety relative to three- and four-engine designs.
„ Reviews the ETOPS record to show that twinjets are well suited
to extended-diversion-time routes (see also Intro and Section 1).
„ Summarizes the ETOPS rule of 2007 (see Section 2), which has
updated the requirements for twinjet extended operations.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
For more than half a century, two-engine operations have been restricted by
14 CFR 121.161, a regulation known as the 60-minute rule. This operating
restriction has limited two-engine airliners to routes that remain at all times
within one hour’s flying time, at single-engine cruise speed, of an airport.
Origin and
intent of the
60-minute rule
Enacted into law in 1953, the 60-minute rule was at the time an appropriate
response to the limited reliability of the piston (i.e., internal combustion)
engines that powered the propeller airliners of the 1940s and early 1950s.
The intent of this piston-era operating restriction
was to ban two-engine airliners (e.g., the Douglas
DC-3) from overwater and other extended routes
then more safely served by four-engine airplanes
(e.g., Douglas DC-6, Lockheed Constellation, and Boeing Stratocruiser).
February 15, 2008
ETOPS Explained
3–1
3. Twin-Engine ETOPS Experience (continued)
Three-engine
airliners also
restricted
Although the three-engine airliners of the late 1920s
and 1930s (e.g., the Ford Tri-Motor) had long since
been phased out of regular U.S. passenger service,
the 60-minute rule of 1953 initially applied to threeengine types as well because of a few isolated instances, such as Alaskan
bush flying, in which trimotors then remained in commercial service.
Jet-age removal
of three-engine
restriction
In 1964, airliners with three turbine engines were
exempted from the 60-Minute Rule, which subsequently applied only to twin-engine operations.
This regulatory modification coincided with the 1964 service debut of the
Boeing 727, the first U.S.-designed trijet. Thus, operation of the 727 and
subsequent trijets (e.g., DC-10, L1011, MD-11) has been unrestricted.
Scope of the
60-minute rule
The 60-minute rule has had virtually global applicability. After ETOPS
flying started in 1985 (see Section 1), the International Civil Aviation
Organization (ICAO), which then recommended a 90-minute operating
limit at all-engine flying speed, revised its recommendations to match the
ETOPS standard of 60 minutes at one-engine-inoperative flying speed.
Advancements
in the jet age
In October 1958, five years after the 60-minute rule of 1953 took effect,
the Boeing 707 entered service. The DC-8 and other jets soon followed
the 707, initiating a rapid transition from piston to turbine propulsion that
profoundly altered commercial aviation.
Over the many decades since the dawn of the jet era, huge strides have been
made in virtually all areas of flight-related technology. High-bypass-ratio
turbofan engines, or fanjets, together with countless other advancements,
have improved the reliability of virtually every airplane system. So great
has this progress been that air travel has been fundamentally transformed
since the piston era a half-century ago. Among the many changes
„ Current-generation turbofan engines are at least 100 times more
reliable than the large piston aero engines of the 1950s.
„ The propulsion-related accident rate of today’s world jet fleet is less
than one percent of that of the 1950s piston-engine airliner fleet.
By the late 1970s, therefore, it was evident that technological progress had
set the stage for two-engine turbine-powered airplanes to safely exceed the
1953 operating restriction. Consequently, the global aviation community
collaborated to develop a conservative, evolutionary regulatory framework
under which modern twinjets, powered by high-bypass-ratio fanjets, could
safely fly extended-diversion-time routes. The result of this activity was of
course ETOPS, which began in 1985 (see the Introduction and Section 1).
February 15, 2008
ETOPS Explained
3–2
3. Twin-Engine ETOPS Experience (continued)
Twinjets have
a rich history
The world’s first jetliner was the de Havilland
Comet I of Great Britain. This four-engine jet
entered service in May 1952 but was withdrawn
after two years following a series of accidents.
The Comet I thus marked an abortive start to the commercial jet age.
The twin-engine Tupolev Tu-104 of Russia inaugurated the world’s first
sustained commercial jet operations in 1956. Based on a Soviet bomber,
this twinjet is today largely forgotten because its
operation was almost entirely confined behind the
“Iron Curtain.” Consequently, few people today
realize that a twinjet—not a four-engine type such
as the 707—inaugurated the age of sustained commercial jet operations.
The Western world’s first twinjet was the Sud
Aviation Caravelle of France. The Caravelle
entered European domestic service in May 1959,
six months after the introduction of the 707.
Other twin-engine transports followed in the 1960s. The BAC One-Eleven
began services in April 1965, the Douglas DC-9 in December 1965, and the
Boeing 737 (the first of three generations) in December 1967.
Two-engine
jets are safe
From 1958 through 2006, the world’s airlines performed some 487 million
jetliner flights. Of this total, twin-engine jets accounted for 333 million
flights or 68 percent of all jetliner departures (fig. 3–1). In 2006, twinjets
logged 92 percent of all commercial jet departures. Throughout this vast
operational experience, twinjets have proven to be at least as safe as jets
with more than two engines. Of course, all commercial jet transports are
enormously safe as ensured by the rigorous type certification process.
As explained above, having more than two engines meant greater safety
back in the piston-engine-and-propeller era a half-century ago. While it
would seem reasonable to expect that having more turbine engines beyond
two would enhance safety in the jet age, data gathered over more than four
decades shows that such is not the case. In fact, every bit of available data
shows that twinjets:
„ Are as safe as or safer than jetliners with three or four engines—as a
category, in fact, twins are the safest and most reliable of all (fig. 3–2).
„ Have never been less safe than four-engine jets since twins were first
introduced at the start of the commercial jet age (fig. 3–3).
February 15, 2008
ETOPS Explained
3–3
3. Twin-Engine ETOPS Experience (continued)
Perceptions
of twinjet safety
Today the traveling public overwhelmingly accepts the use of two-engine
jetliners on extended air routes. This broad acceptance shows that public
perceptions have generally caught up with the realities of modern twinjet
safety and reliability. Thus, a paradigm shift can be said to have occurred
in people’s thinking as regards two-engine airliners and their operation.
Of course, outdated perceptions can have “staying power” in cases such as
this where the truth is counterintuitive. Consequently, the media, general
public, and sometimes even regulatory agencies and pilots’ associations
occasionally still fall prey to the lingering misconception that more engines
mean greater safety.
Twinjets
relative to
other jetliners
Analysis of the vast operational record shows that:
„ Modern twinjets are enormously safe—relative to three- and fourengine jetliners, twinjets consistently demonstrate
„ The lowest overall hull-loss accident rate.
„ The lowest engine-related hull-loss accident rate.
„ Modern twinjets are the most reliable of all jets, demonstrating
„ The highest schedule reliability rates (twinjets are simpler with
fewer systems to maintain and less to go wrong).
„ The lowest rate of flight interruptions due to engine in-flight
shutdowns (IFSD).
In addition to being so safe and reliable, twins are the most efficient and
economical jetliners. They burn less fuel and create fewer emissions.
In light of this spectrum of advantages, the only technical reason to design
a jetliner today with more than two engines is when the practical size limit
of engines is exceeded, precluding a two-engine approach.
Safety by
design
Boeing develops its twinjets using the latest baseline in safe design. The
Boeing 777, Next-Generation 737, and 787 Dreamliner programs have all
built further on all that Boeing learned with previous-generation jets, which
in the past often tended to have three or four engines. As explained above,
the enormous reliability of fanjet engines underlies the safety of twinjets.
Further assuring safety, certification requires that all jet transports be able
to experience an engine failure at the worst possible time—i.e., at takeoff
when they are heaviest and have just attained flying speed—and climb out
successfully. Because of this design requirement, twinjets are overpowered
relative to jets with three or four engines, giving them an additional safety
margin throughout the entire flight. An explanation of this twinjet “thrust
margin” advantage is provided below.
February 15, 2008
ETOPS Explained
3–4
3. Twin-Engine ETOPS Experience (continued)
Twinjet thrustrequirement
design insight
Jets have greatest need of thrust at takeoff. The amount of thrust needed
is about 15 percent of the maximum takeoff gross weight (MTOGW) of
the airplane (i.e., when it’s fully loaded). As this formula shows, a jetliner
with a 200,000-pound MTOGW would require 30,000 pounds of thrust:
ThrustReq = MTOGW x 15%
Of course, the number of engines determines the amount of thrust needed
per engine. Or stated conversely, the amount of thrust available per engine
affects the number of engines that are required.
ThrustReq = ThrustPerEngine X EngineQty
Fewer engines can be used if sufficient thrust is available per engine. A
safety margin is included to ensure sufficient thrust in the event an engine
fails on takeoff. Thus, one engine is subtracted from the equation:
ThrustReq = ThrustPerEngine X (Engine Qty - 1)
For a twin-engine airplane, “Engine Qty – 1” equals one, so the thrust from
one engine must equal the total thrust needed for takeoff. Advancements
in engine technology have allowed such high thrust requirements to be met.
For example, the 747-100 entered service in 1970 with the largest fanjet
engine of its day, which was rated at 43,000 pounds of thrust. As of 2004,
the most powerful available engine produces 115,000 pounds of thrust.
As a result of this additional thrust per engine, the engines of twinjets tend
to operate at lower power settings than those of three- and four-engine jets.
Should an engine be shut down in flight, all twinjets have ample power
remaining for continued flight to an alternate airport. As for single-engine
cruise during propulsion-related diversions, flying safely on one engine is a
planned and certified design capability of twinjets.
The role
of ETOPS
Given that all modern commercial jet transports and their fanjet engines are
enormously safe and reliable, it can be seen that the purpose of the ETOPS
program is not to make twinjets “safe enough” for extended operations, but
rather to further enhance operations on extended-diversion-time air routes.
ETOPS twins—
the preferred
configuration
Over 90 percent of new commercial jetliners delivered today are twinjets.
The industry has standardized on two engines as the preferred design configuration because twins are the most efficient, reliable, economical, and
environmentally preferred of all jetliners.
For many years, ETOPS twinjets have set the highest standard for safety
and schedule reliability on routes with extended diversion times. Twinjet
ETOPS has been so successful that—aside from regional jets dedicated
to short haul—virtually all twinjets delivered today are ETOPS capable.
February 15, 2008
ETOPS Explained
3–5
3. Twin-Engine ETOPS Experience (continued)
Design
approach
Just a quarter-century ago, all long-haul flying was by jetliners with three
or four engines. Today, twinjets—which predominate at short and medium
range—also increasingly fly long-haul and very-long-haul routes (fig. 3–4).
Data analysis of operational experience shows that
„ Twins are well suited to the spectrum of operational demands.
„ Twins are safe, reliable, and efficient at all ranges.
Consequently, the industry only designs new airplanes with more than two
engines when limitations in propulsion technology constrain a two-engine
approach. In fact, every all-new jetliner introduced in the last two decades
or currently under development has two engines except:
„ Airbus A340—when it was designed in the late 1980s, no engines
existed that were sufficiently powerful for a two-engine approach.
„ Consequently, Airbus designed a single airframe that has four
engines for long range (A340) or two for short range (A330).
„ Only after Airbus had locked into the above concept did Boeing,
with characteristic vision, launch the 777 and challenge the engine
companies to design engines twice as powerful as any in existence.
„ Airbus A380—the Airbus jumbo jet was designed with four engines
because fewer than that would not have provided sufficient thrust.
Facts and data
support ETOPS
As of December 2006, about 5.5 million ETOPS twinjet flights have been
logged, and some 143 operators worldwide currently fly about 1,700 more
every day. This vast industry experience shows that
„ Twinjets are very well suited to and accepted by the traveling public
in long-range services on extended-diversion-time routes.
„ ETOPS ranks among the very safest and most reliable of all flight
operations, and sets the highest standard in intercontinental air travel.
„ ETOPS has already indirectly benefited all commercial aviation by
spearheading engine and other reliability improvements.
For more information about the development and success of ETOPS, see
the Introduction and other sections of ETOPS Explained.
The U.S. ETOPS
rule of 2007
February 15, 2008
On February 15, 2007, the U.S. Federal Aviation Administration enacted
a new ETOPS rule that brought big changes to ETOPS. This rulemaking:
„ Implemented updated requirements based on the analysis of a vast
amount of enormously successful ETOPS experience by operators.
„ Applied many of the proven protections of ETOPS to further enhance
the extended operation of three- and four-engine passenger jetliners.
„ Codified ETOPS for the first time directly in the U.S. federal aviation
regulations as befits such wide-scale flight operations.
ETOPS Explained
3–6
3. Twin-Engine ETOPS Experience (continued)
The U.S. ETOPS
rule of 2007
(cont’d)
The U.S. ETOPS rule of 2007
„ Recognizes the leading safety and reliability of long-range twinjets.
„ Makes the designed and certified capabilities of the airplane type
the basis for determining that type’s maximum diversion authority.
„ Provides for beyond-180-minute ETOPS and sets the stage for compliant air carriers to fly properly configured and approved twinjets
on optimal flight routings between virtually any two cities on earth.
„ Applies proven ETOPS requirements to further enhance the extended
operation of passenger airplanes with three or four engines, not just
twinjets, because all airplanes flying extended-diversion-time routes
contend with the same operating challenges.
„ Establishes different applicability thresholds for two-engine airplanes
versus three- and four-engine airplanes (ETOPS rules apply on routes
that take a twin beyond 60 minutes of an airport, and on routes that
take a tri or a quad beyond 180 minutes of an airport).
See Section 2 for more information about the U.S. ETOPS rule of 2007.
About ETOPS
propulsion-risk
requirements
ETOPS flying began in 1985 with 120-minute diversion authority that let
compliant operators fly approved twinjets up to 2 hours (at single-engine
cruise speed) of an airport. For these operations, the conservative ETOPS
program introduced a framework of requirements that enhanced safety and
reliability. Chief among these ETOPS enhancements was the requirement
for increased propulsion reliability to reduce propulsion-related risks.
Based on a 7-hour flight on a route with this 2-hour diversion authority, the
ETOPS program in 1985 established an engine in-flight shutdown (IFSD)
rate of 0.05 IFSDs per 1,000 engine hours as the ETOPS eligibility rate for
the approved ETOPS airplane types (i.e., airframe / engine combinations)
comprising the ETOPS world fleets. Highly conservative risk-model
calculations underpinned this IFSD eligibility rate.
When 180-minute ETOPS became available in 1988, the same ICAO riskcomputation methodology determined that an IFSD eligibility rate of 0.04
IFSDs per 1,000 engine hours would yield equivalent safety for twinjets on
a 7-hour flight with a 3-hour extended-diversion time. However, the FAA,
citing “uncertainties associated with assumptions identified in the ICAO
study,” 1 cut this target in half, thus challenging the industry to achieve an
IFSD rate of 0.02 per 1,000 engine hours.
In fact, Boeing twinjets did achieve this propulsion rate by 1989. By 1992,
Boeing and the industry again cut this rate in half with an average world
(continued)
1
Advisory Circular AC 120-42, FAA; p. 6, par. 7, June 6, 1985.
February 15, 2008
ETOPS Explained
3–7
3. Twin-Engine ETOPS Experience (continued)
About ETOPS
propulsion-risk
requirements
(cont’d)
IFSD rate of 0.01 IFSDs per engine hour. Today, Boeing ETOPS twinjets
consistently average 0.005 IFSDs per 1,000 engine hours! So low is this
rate that only a relatively small number of today’s young airline pilots on
Boeing equipment will ever experience an engine failure aloft during their
entire careers. These astonishing gains in propulsion reliability represent
one of the most dramatic trends in the history of commercial aviation!
In 2000, meantime, 207-minute ETOPS became available on a flight-byflight exception basis to approved 777 operators flying the North Pacific.
Extending the 180-minute propulsion risk model to 207 minutes yielded
a propulsion reliability rate of 0.019 IFSDs per 1,000 engine hours. This
target became the required eligibility rate for 207-minute approvals.
About 2007
ETOPS rule
propulsion
requirements
Because the ETOPS rule of 2007 provides a framework under which air
carriers may safely fly approved twinjets beyond 180 minutes of an airport,
and since this rule makes the design capabilities of the airplane type the
basis for determining that type’s maximum-allowable diversion authority,
all available risk models were examined for flights as long as 20 hours
with a diversion time of up to 10 hours. This was an intentionally extreme
hypothetical analysis because no air route in the world would ever require
an airplane to perform so long an extended diversion.
For this hypothetical mission, all these risk models converged at or slightly
above an IFSD rate of 0.01 per 1,000 engine hours (fig. 3-5). None came
in below the 0.01 IFSD rate. To put the results into perspective, this IFSD
rate is so enormously low that it places the risk of having both of a twinjet’s
engines fail during the same flight due to unrelated factors (i.e., not as the
result of a common cause like volcanic ash or fuel starvation) at the same
level of extreme improbability as the risk of a total loss of all hydraulics or
that of losing essential electrical power.
In fact, the world fleet of Boeing ETOPS jetliners today routinely achieves
an IFSD rate of about 0.005 per 1,000 engine hours. Therefore, the 2007
ETOPS rule’s intent of maintaining current propulsion safety rates will at
the very least be met on even the longest extended-diversion-time flights.
About 2007
ETOPS rule
type-design
requirements
February 15, 2008
To continue reducing the rate of airplane propulsion and system failures
that might prompt a flight to divert, the 2007 ETOPS rule implements typedesign changes that codify existing ETOPS policies, practices, and special
conditions in a uniform set of regulations for airplanes and engines. This
updating of requirements to Parts 21, 25 and 33 of the U.S. federal aviation
regulations ensures that airplane designs approved for beyond-180-minute
ETOPS will maintain the same high standards that have exemplified ETOPS
experience since 1985.
(continued)
ETOPS Explained
3–8
3. Twin-Engine ETOPS Experience (continued)
About 2007
ETOPS rule
type-design
requirements
(cont’d)
At present, it appears that a diversion-time limit of about 330 minutes will
support optimal flight operations between any two cities on earth. After
assessing the ability of its current and projected widebody fleet to meet this
type-design goal, Boeing decided to certify the long-range versions of the
787 Dreamliner twinjet to a diversion time limit of 330 minutes. Boeing is
also pursuing 330-minute ETOPS approvals for some 777 twinjet models as
well as for the 747-8 Intercontinental, which is the passenger version of this
next major derivative of the four-engine 747. These and all Boeing product
decisions are based on customer needs.
It should be noted that the 787 and 747-8 were launched prior to passage of
the ETOPS rule of 2007 and are consequently not immediately subject to its
type-design requirements. Nevertheless, Boeing is voluntarily complying
with the new rule’s type-design requirements from the outset.
Conclusions
This section of ETOPS Explained has shown that two-engine jetliners
„ Have been subject to a 1953 operating restriction imposed because
of the limited reliability of piston engines during the propeller era.
„ Have always as a category demonstrated leading safety and reliability.
„ Are extremely well suited to long-haul flight operations and ETOPS.
„ Have become the industry’s standard configuration:
„ More than 90 percent of jetliners delivered today are twinjets.
„ Manufacturers no longer design with more than two engines unless
constrained by limitations in propulsion technology (i.e., insufficient
thrust available per engine to allow a two-engine configuration).
This section has also shown that ETOPS twinjet flying
„ Began in 1985 as a conservative, evolutionary program that allows
twinjets to safely exceed the 60-minute rule of 1953.
„ Let airlines and their passengers benefit from the leading safety,
reliability, efficiency, economy, and environmental preference of
modern twinjets.
„ Sets the highest standard for safe, reliable flight operations and is the
state of the art in intercontinental air travel.
The U.S. ETOPS rule of 2007 lets operators worldwide build further on the
industry-leading safety and reliability of long-range twinjets. To maximize
operator flexibility, Boeing elected to certify the 787 Dreamliner twinjet
and selected 777 twinjet models to a maximum diversion time limit of 330
minutes. Boeing is also certifying the four-engine 747-8 Intercontinental
to this maximum-allowable ETOPS diversion-time limit.
February 15, 2008
ETOPS Explained
3–9
Twins! - The Market Has Decided
All Western Commercial Jets Over 60,000 lbs Gross Weight
20,000,000
Twins
1-11
717
737-1/200
737-3/4/500
737NG
757
767
777
A300-600
A300-Early
A310
A318
A319
15,000,000
Flights
per year
Tri's
Quads
727
A320
DC-10
A321
L1011
A330
CRJ7/900 MD-11
Trident
DC9
Emb 170/190
F100
F28
MD80
MD90
Mercure
SE-210
146
146RJ
707/720
747-400
747-Early
880/990
A340
Comet
Concorde
DC8
VC-10
Twins
10,000,000
Note: From the year 2005 to 2006 Twin flights went up 5.0%.
Tri flights went down 10.8%.
Quad flights went down 6.3%.
5,000,000
Tri's
Quads
Figure 3-1
Years
2006
2004
2002
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
1958
0
Twins Have the Lowest Accident Rate - Both Total and Propulsion Related
Hull Loss Accident Rates as of 2006
3
Twins
2
Hull Losses
Per Million
Departures
1-11
717
737-1/200
737-3/4/500
737NG
757
767
777
A300-600
A300-Early
A310
A318
A319
Tri's
A320
A321
A330
CRJ7/900
DC9
EMB
170/190
F100
F28
MD80
MD90
Mercure
SE-210
727
DC-10
L1011
MD-11
Trident
Quads
146
146RJ
707/720
747-400
747-Early
880/990
A340
Comet
Concorde
DC8
VC-10
Total 48 year rate 1959 - 2006
Last 10 year rate 1997 - 2006
Propulsion related portion of rate
1
Tri's had no
propulsionrelated
accidents
in the last
10 years,
partly
because of
so few
flights.
0
Twins
Tri's
Figure 3-2
Quads
Hull Loss Accident Rates - Twin vs Quad
10 year rolling Average
3.5
Western built jet engine airplanes over 60,000 lbs gross weight.
3
2.5
Hull Loss
Accidents
per Million
Departures
Quads
2
1.5
1
Twins
0.5
0
1975
1980
1985
1990
Figure 3-3
1995
2000
2005
Most Long-Range Flying Today is by Twinjet
Total Flights Over 3,000 nmi (~8 hrs) from August Official Airline Guide each year
Twin Total
10,000
737
757
767
777
A300
A310
A320
A330
Tri Total
Quad Total
DC10
L1011
MD11
707
DC8
Twins
747
A340
8,000
6,000
4,000
2,000
Tri's
Figure 3-4
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
0
1985
(from
August
OAG
each year)
Quads
1984
Scheduled
flights
per
week
Twins Propulsion Risk Models Converge
For a maximum mission of 20 Hours with 10 Hour Diversion
ETOPS
Div
Time
(Rule
Time)
1
2
3
3.45
4
5
6
7
8
9
10
ICAO
(1)
0.066
0.046
0.038
0.035
0.033
0.029
0.027
0.025
0.023
0.022
0.021
FAA AC
120-42 a,
207 min
Policy
(2)
0.050
0.020
0.019
JAA IL
#20
Relative
Risk
Relative
Risk
FAA
ETOPS
Exposure
(3)
0.036
0.025
0.021
0.019
0.018
0.016
0.015
0.014
0.013
0.012
0.011
Baseline Baseline
0.05
0.02
(Linear) (SQRT)
(4)
(5)
0.100
0.035
0.050
0.024
0.033
0.020
0.029
0.019
0.025
0.017
0.020
0.015
0.017
0.014
0.014
0.013
0.013
0.012
0.011
0.012
0.010
0.011
Index
EEI
Constant
Boeing
NPA –
Phased
Mission
Analysis
(6)
0.026
0.019
0.016
0.015
0.014
0.013
0.013
0.012
0.012
0.012
0.011
• All risk models for twins converge at 0.01/1000 IFSD rate
• This puts the likelihood of a dual independent In-flight shutdown on
the same level as loss of all hydraulic or essential electrical power
Figure 3-5
(7)
0.023
0.017
0.014
0.013
0.013
0.012
0.011
0.010
0.010
0.010
0.010
Section 4
Three- and Four-Engine Airplanes
and ETOPS
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Reviews the history of three- and four-engine airliner operations
and contrasts them with two-engine operations (see Section 3).
„ Examines the regulatory environment in which these “tri and
quad” operations evolved.
„ Explains why the U.S. Federal Aviation Administration (FAA)
in 2007 acted to broaden ETOPS beyond twinjets to also embrace
the extended operation of three- and four-engine passenger jetliners.
„ Reviews the effects of this 2007 FAA rulemaking on affected threeand four-engine operators, who today must meet updated ETOPS
requirements when flying routes that take the airplane beyond 180
minutes of an alternate airport.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s table of contents.
Historical
overview
Globe-spanning commercial flight operations emerged after World War II
using an infrastructure of airfields built for that conflict. In the immediate
postwar era, transoceanic flying was the domain of four-engine propeller
airliners like the Douglas DC-4 / - 6 / -7 series, Lockheed Constellation, and
Boeing 377 Stratocruiser. Two-engine propeller airliners, like the Douglas
DC-3 or Convair 240, served domestic and regional routes (see Section 3).
The era of sustained commercial jet travel began with the Boeing 707 in
1958. Like the piston-powered airliners it superseded in service, that 707
had four engines. So did the de Havilland Comet IV and Douglas DC-8,
and other long-range transports of the first generation of commercial jets.
Evolution of
operations
January 15, 2008
The reason that the Comet, 707, and DC-8 had four engines was the limited
thrust of early jet engines, which demanded a four-engine design approach
to achieve sufficient aggregate thrust for long-haul flight operations. Since
turbine power plants are far more reliable than piston engines, overall flight
safety was not a factor in this design decision.
(continued)
ETOPS Explained
4–1
4. Three- and Four-Engine Airplanes and ETOPS (continued)
Evolution of
operations
(cont’d)
The dramatic gains in propulsion reliability resulting from the industry’s
rapid transition to jets set the stage for jet transports to be developed with
fewer than four engines. Two- and three-engine jetliners quickly followed
the four-engine jets into commercial service, as indicated below.
First decade of sustained jet operations (1958–1968)
Twinjets
ƒ
ƒ
ƒ
ƒ
ƒ
1
2
3
4
Airplane
operating
restriction
Trijets
Tupolev Tu-1041
Caravelle, 1959
BAC 111, 1965
Douglas DC-9, 1965
Boeing 737, 19684
ƒ HS Trident, 1964
ƒ Boeing 727, 1964
Four-engine jets
ƒ DH Comet IV, 19582
ƒ Boeing 707, 19583
ƒ Douglas DC-8, 1959
The Tupolev Tu-104—a twinjet—inaugurated the world’s first sustained jet services in 1956. Based on a Soviet
jet bomber, the Tu-104 is today overlooked because its operations were largely confined behind the “Iron Curtain.”
The Comet IV was a redesign of the de Havilland Comet I, the world’s first jetliner, which entered service in 1952
but was withdrawn from service two years later following a series of accidents.
Following the Comet IV into service by two weeks, the vastly more successful 707 marks the real emergence of
sustained jet operations and the real beginning of the industry’s transition to jets.
The first 737 generation entered service in 1968, the middle generation in 1984, and the current generation—
today’s Next-Generation 737 family—in 1998.
In 1953, a U.S. federal aviation regulation imposed an operating restriction
on airliners with fewer than four engines. Informally called the 60-minute
rule, this propeller-era regulation limited two- and three-engine airliners to
routes that remain at all times within one hour’s flying time, at one-engineinoperative cruise speed, of an alternate airport.
The 60-minute rule was an appropriate regulatory response to the limited
reliability of the piston aero engines that powered the world commercial
airliner fleet at the time of its passage.
Trijets
exempted
In 1964, the FAA exempted three-engine, turbine-powered airplanes from
the 60-minute rule, which thereafter restricted just twin-engine operations.
This U.S. regulatory action recognized the dramatic engine reliability gains
brought about by the transition to turbine propulsion.
The widebody
era begins
in 1970
The widebody era of jet travel began in January 1970 with the introduction
to service of the Boeing 747, the world’s first twin-aisle airliner. The 747
was a four-engine design because fewer engines would not have provided
sufficient thrust.
Following the 747 into service were the twin-aisle Douglas DC-10 (1971),
Lockheed L-1011 (1972), and Airbus A300B (1974). Widebody jets—the
747 in particular—soon came to dominate long-haul air travel with oceanspanning services between the “international gateway” hub airports of the
world’s different continents and regions.
January 15, 2008
ETOPS Explained
4–2
4. Three- and Four-Engine Airplanes and ETOPS (continued)
Tri and quad
dominance
begins to erode
Intercontinental air travel remained the domain of three- and four-engine
widebody jetliners until
„ Modern, fuel-efficient twinjets with long range capability entered
service in the 1980s (e.g., Boeing 767, Airbus A310) and 1990s
(e.g., Boeing 777, Airbus A330).
„ The ETOPS program began in 1985, providing a framework under
which the industry could fly these long-range twinjets on overwater
and other routes with the potential for an extended diversion (see the
Introduction and Section 1).
Twinjets are
superseding
tris and quads
In a dramatic trend that began in the 1980s, two-engine jetliners have been
displacing three- and four-engine jets in long-range service (fig. 4–1). The
share of long-haul flights performed by tris and quads continues to decline,
while that logged by twinjets rises. On routes that take the airplane more
than one hour from an alternate airport, these twins fly under ETOPS rules.
Jetliner range
capabilities
have risen
Jetliner range capabilities have risen dramatically over the decades. As a
result, nonstop flights of a dozen or more hours are today common, and
flights of 18 or even 20 hours are not unusual. This trend has allowed the
operators of intermediate-capacity twinjets to bypass traditional hubs with
point-to-point services directly linking a growing number of the world’s
cities. These smaller long-haul jets—such as the 777 or 787 Dreamliner—
can profitably serve long routes with insufficient travel demand for a 747.
A common
operating
environment
As airline range has increased, so too has the number of flight operations
that traverse remote areas of the world where airplanes are at times far from
an airport. Regardless of how many engines they have, all jets flying these
extended-diversion-time air routes share a common operating environment.
Thus, they all contend with similar operating challenges in terms of terrain,
weather, and limitations in navigation and communications infrastructure.
Such being the case, by the 1990s awareness had arisen within the global
aviation community that the ETOPS regulatory framework—which then
applied only to twinjet extended operations—could also further protect and
enhance the extended operation of three- and four-engine airplanes.
The ETOPS
rule of 2007
January 15, 2008
To achieve this higher and more uniform standard for extended operations,
the U.S. FAA enacted the ETOPS rule of 2007. This regulatory updating
codifies current FAA policy, industry best practices and recommendations,
and international standards designed to ensure that long-range flights continue to operate safely.
(continued)
ETOPS Explained
4–3
4. Three- and Four-Engine Airplanes and ETOPS (continued)
The ETOPS
rule of 2007
(cont’d)
Enacted on February 15, 2007, the U.S. ETOPS rule of 2007
„ Codifies ETOPS for the first time directly in the U.S. federal
aviation regulations as befits such wide-scale flight operations.
„ Implements requirements updated according to the analysis of facts
and data compiled during more than two decades of enormously
successful ETOPS twinjet operations worldwide.
„ Applies many proven ETOPS requirements more broadly to also
protect the operation of three- and four-engine passenger jetliners
when they perform extended-diversion-time flight operations.
See Section 2 for a review of the U.S. ETOPS rule of 2007. What follows
in this section is just a partial description of this rulemaking in the specific
context of its applicability to, and effect on, current three- and four-engine
operators who perform passenger operations on routes with the potential for
an extended-duration airplane diversion.
Different
ETOPS
thresholds
Although the 2007 rulemaking applies to the extended operation of threeand four-engine passenger airplanes as well as to twinjets, the threshold at
which ETOPS requirements apply differs for twins versus tris and quads.
„ For twinjets, ETOPS applies as was previously the case on routes
that at some point take the airplane beyond 60 minutes, at singleengine cruise speed, of an airport (fig. 4–2).
„ For passenger jetliners with more than two engines, ETOPS applies
on routes that take the airplane beyond 180 minutes, at one-engineinoperative cruise speed, of an airport (fig. 4–3).
Specific
requirements
The ETOPS rule of 2007 applies the following ETOPS requirements to
three- and four-engine passenger airplanes when flown on routes that take
the airplane beyond 180 minutes of an airport:
„ Alternate airport planning—operators must identify the alternate
airports on which their extended operations rely, and they must ensure
that these alternate airports meet ETOPS rescue / firefighting services
(RFFS) requirements and all other stated requirements.
„ Dispatch or flight release—operators must ascertain before dispatch
or flight release that the planned alternate airports are above required
weather minimums, and must verify at the beginning of the ETOPS
phase of flight that each ETOPS alternate airport will be available
when it might be needed.
„ Passenger recovery plan—for each ETOPS alternate airport along
the route, a plan must be developed to ensure the well-being of
passengers and crew members stranded at that airport by an airplane
diversion, providing for their prompt retrieval.
(continued)
January 15, 2008
ETOPS Explained
4–4
4. Three- and Four-Engine Airplanes and ETOPS (continued)
Specific
requirements
(cont’d)
„
„
„
„
Exemptions
applicable to
tris and quads
ETOPS fuel reserve—operators must carry a reserve that ensures
sufficient fuel even in the enormously unlikely event of a maximumduration diversion at low altitude following loss of cabin pressure.
Cargo fire suppression and other time-limited systems—operators
must ensure that their ETOPS tris and quads have sufficient cargo fire
suppression system capacity to allow a cargo fire to be continuously
suppressed throughout the maximum planned diversion time for the
route being flown plus 15 minutes.
Communications—for all ETOPS beyond 180 minutes, the airplane
must have satellite communication (SATCOM) voice communications
capability. Another form of communication must also be available.
Performance data—flight crews and dispatchers must have detailed
airplane performance data available that describes all aspects of the
airplane’s performance in normal and nonnormal situations, including
those that might be encountered during an extended diversion.
The ETOPS rule of 2007 specifies two exemptions for the operators of
airplanes with more than two engines:
„ Passenger operations—three- and four-engine passenger airplanes
are exempted from the rule’s ETOPS maintenance requirements.
„ All-cargo operations—three- and four-engine freighter airplanes
are entirely exempted from ETOPS.
In the case of freighters, the FAA states that tri and quad operations were
exempted because the cost impact on operators could not be justified. In
contrast, twinjet freighter operations continue to be subject to ETOPS.
About ETOPS
maintenance
In the 2007 rule’s preamble, the FAA states the following:
The FAA strongly believes that all operators would benefit from an
ETOPS maintenance program. However, the FAA agrees with many of
the commenters that the cost of implementing this new requirement for
airplanes with more than two engines would be significant. The FAA has
determined that this cost cannot be justified based on the current level of
safety achieved by the combination of engine reliability and the engine
redundancy of this fleet of airplanes. 1
Nevertheless, many of the world’s tri and quad operators have voluntarily
raised their maintenance standards to ETOPS levels because it helps them
avoid on-wing engine failures and other costly service disruptions. This
elective application suggests that ETOPS maintenance practices are cost
effective, and that their safety and reliability benefits are well appreciated.
1
U.S. Federal Register, Washington, DC, vol. 72, no. 9, January 16, 2007, p. 1836.
January 15, 2008
ETOPS Explained
4–5
4. Three- and Four-Engine Airplanes and ETOPS (continued)
Compliance
cost mitigation
To ease the transition for current three- and four-engine operators, the 2007
ETOPS rule has specified delayed compliance dates, including:
„ Operating limitation—operators have a 1-year grace period (ending
Feb. 15, 2008) before tris and quads are restricted to routes that remain
at all times within 180 minutes of an airport unless flying ETOPS.
„ SATCOM—operators also have 1 year to equip their airplanes with
SATCOM voice communications equipment.
„ Passenger recover plans and training—operators also have 1 year to
develop passenger recovery plans for the alternate airports on which
their extended operations will rely, and to train their dispatchers and
flight crews for their specific roles and responsibilities in creating and
implementing these recovery plans.
„ Cargo fire suppression—operators have 6 years (ending February
15, 2013) to bring their existing three- and four-engine fleets into
compliance with the rule’s cargo fire suppression requirement.
These delayed compliance dates serve to mitigate costs for existing tri and
quad operators. For example, the 6-year period for meeting the rule’s cargo
fire suppression system requirement will allow these system upgrades to be
performed during regularly scheduled airplane heavy-maintenance cycles.
ETOPS
enhances
flight safety
ETOPS enhances flight safety in many ways. One example is by alternate
airport planning. All extended-diversion-time flight operations can benefit
from alternate airport planning, which increases flight crew options if they
ever need to divert to an airport other than the intended destination.
About
airplane
diversions
Airplane diversions are rare events that can never be entirely eliminated
because most are unrelated to the operation of the airplane, its systems,
or its engines. Analysis of ETOPS operational data shows that:
„ Diversions can happen for many reasons, among them:
„ Passenger medical emergency.
„ Fuel leak.
„ Severe turbulence.
„ Cabin decompression.
„ Adverse winds.
„ Engine or other significant
system failure.
„ Smoke in the flight deck or cabin.
„ Fewer than 10 percent of all diversions are related to the airplane.
„ Fewer than 3 percent of all diversions result from an in-flight engine
failure—fanjets rarely fail but when they do, it’s usually on takeoff,
climb, or descent rather than in cruise when ETOPS is performed.
Consequently, airplanes with two, three, and four engines can all benefit
from ETOPS. See Section 2 for a description of the ETOPS rule of 2007,
and Section 8 for a more detailed discussion of airliner diversions.
January 15, 2008
ETOPS Explained
4–6
4. Three- and Four-Engine Airplanes and ETOPS (continued)
ETOPS
fuel reserve
requirement
Although decompressions, or the sudden loss of cabin pressure in flight,
are extremely rare, they can strike any jetliner. When they do, the flight
crew must immediately descend, typically to 10,000 feet. An emergency
diversion to an en route alternate airport is then generally required because
airplane range is significantly reduced when flying at low altitudes.
Under the ETOPS rule of 2007, three- and four-engine passenger jetliners
flying ETOPS must carry additional fuel to cover decompression, as twins
in ETOPS service have done since 1985. Before the 2007 rule, affected tri
and quad operators were not required to carry a decompression fuel reserve,
although many did so as a matter of internal airline policy.
Critical fuel
analysis
Because of the severe effect it has on airplane range, loss of cabin pressure
is a key element in the critical fuel scenario analysis that all operators must
perform before they may fly a new route. This analysis assumes a decompression at the worst possible point along the route. A concurrent engine
failure is further assumed if it would add to the total amount of fuel used.
The analysis portrays a descent to low-altitude with auxiliary power unit
(APU) running, a 15-minute hold at 1,500 feet, and a successful landing.
The total thus computed is known as the critical fuel reserve.
ETOPS makes such worst-case, low-level diversion planning the basis for
a safety-enhancing fuel reserve that is a key ETOPS operational protection.
Depending on the route, this ETOPS-specified fuel reserve may or may not
be greater than the normal fuel reserve computed according to the airline’s
own internal practices.
The ETOPS
cargo fire
suppression
requirement
Many airplane systems enhance safety during flight. Of these, the cargo
fire suppression system is generally the most time-limited. Therefore, the
application of proven ETOPS twinjet cargo fire suppression requirements
to tri and quad extended operations can further protect those airplanes, their
passengers, and their flight and cabin crews on routes with the potential for
an extended diversion.
ETOPS twinjets have been required since 1985 to carry sufficient cargo fire
suppressant to be able to continuously suppress a cargo fire throughout the
maximum-planned diversion time of the route being flown plus 15 minutes.
Under the ETOPS rule of 2007, three- and four-engine passenger jetliners
must also comply with this safety-enhancing requirement when performing
extended operations. As noted above, tri and quad operators have a 6-year
grace period ending February 15, 2013, to comply with this requirement.
January 15, 2008
ETOPS Explained
4–7
4. Three- and Four-Engine Airplanes and ETOPS (continued)
Non-ETOPS
rule provisions
affecting tri and
quad operations
Also included in the ETOPS rule of 2007 are two non-ETOPS provisions
that affect three- and four-engine airplane operations:
„ FAA polar policy—formalizes regulatory requirements for polar
area operations and provides a uniform process for operators seeking
polar route authority.
„ Tri and quad decompression fuel reserve—restricts all affected
three- and four-engine airplanes to routes that remain 90 minutes,
at all-engines-operating speed, of an airport unless a decompression
fuel reserve is carried.
The FAA
polar policy
All flight operations conducted by affected carriers in the North and South
Polar areas (i.e., everything above 78° N latitude and below 60° S latitude)
are subject to this FAA polar policy, which was initially implemented as an
FAA Policy Letter of 2001. Within these polar areas, this policy applies at
all times to all airplanes, passenger and cargo, regardless of diversion time
or number of engines.
Under this FAA policy, operators are required to perform diversion airport
planning and develop and implement passenger recovery plans. Despite
these similarities to ETOPS, however, this policy is distinct from ETOPS
because polar flight operations entail unique requirements, such as special
onboard equipment and a fuel freeze strategy.
Tri and quad
decompression
fuel reserve
The U.S. ETOPS rule of 2007 also enacted a general (i.e., not-ETOPS)
operating restriction on three- and four-engine airplanes that limits them
to routes remaining within 90 minutes of an airport unless they carry a
decompression fuel reserve. This operating restriction ensures sufficient
reserve fuel for the airplane to reach an alternate airport even in the event
of a low-level diversion. Of course, many current tri and quad operators
already carry a depressurization fuel reserve as a matter of airline policy.
Note that this broadly applied fuel reserve requirement is distinct from the
ETOPS-specific fuel reserve imposed on for two- , three- , and four-engine
airplanes when they fly extended operations, as described above.
ETOPS
type-design
requirements
The ETOPS rule of 2007 codifies existing ETOPS policies, practices, and
special conditions in a uniform set of regulations for airplanes and engines.
This updating of ETOPS type-design requirements in 14 CFR Parts 21, 25
and 33 will continue to reduce the rate of propulsion and system failures
that might prompt an airplane to divert. It ensures that airplane designs
approved for beyond-180-minute ETOPS will continue to demonstrate the
same high standards that have exemplified ETOPS experience since 1985.
(continued)
January 15, 2008
ETOPS Explained
4–8
4. Three- and Four-Engine Airplanes and ETOPS (continued)
ETOPS
type-design
requirements
(cont’d)
Under the 2007 rule, existing three- and four-engine passenger jetliners do
not need type-design approval to perform extended-diversion-time flight
operations. However, when these existing tri and quad passenger planes
perform ETOPS, they are of course subject to the 2007 rule’s operational
requirements as described above in this section.
The 2007 rule grants manufacturers an 8-year delayed-compliance period
to incorporate ETOPS design enhancements in their existing three- or fourengine airplanes if they remain in production. This grace period expires
February 17, 2015. Any current airplane types built on or after this date
must meet these type-design requirements if they are to fly ETOPS.
Boeing is today developing the 747-8, a major derivative of the four-engine
747 that will enter service in 2009 as a freighter, and in 2010 as a passenger
plane called the 747-8 Intercontinental. Although the 747-8 was launched
before the ETOPS rule of 2007 took effect, Boeing is voluntarily designing
the 747-8 to comply with these updated ETOPS type-design requirements.
The 747-8 Intercontinental is being designed and certified for a maximum
ETOPS diversion time limit of 330 minutes, which is sufficient to support
optimal flight operations between any two cities on earth.
It should be noted that current three- and four-engine airplane types have
already benefited indirectly from ETOPS. All commercial flight operations
are today safer and more reliable thanks to improvements in the reliability
and robustness of airplane engines and other systems that were pursued and
achieved under the ETOPS program.
Conclusions
When the commercial jet age began, long-range jetliners had four engines
because insufficient thrust was available per engine to allow designs with
fewer engines. Jets with two or three engines also emerged early on, but
were limited to short-haul markets by thrust constraints and the poor fuel
efficiency of early turbine engines.
In the early 1980s, long-range twinjets became available. Airlines quickly
began using them to bypass traditional hubs with a rising number of direct
services to a growing number of airports. Flying under ETOPS rules since
1985, these capable twinjets demonstrated their suitability to long-haul and
very-long-haul services on routes with extended diversion times.
In a dramatic trend, smaller fuel-efficient twinjets have been displacing the
big tris and quads that once dominated long-haul air travel. These mediumcapacity ETOPS twins link existing hubs with more frequent services; they
also bypass them to bring direct flights to a growing number of the world’s
smaller cities, many of which lack sufficient travel demand to support big
jetliners the size of a 747 or larger.
(continued)
January 15, 2008
ETOPS Explained
4–9
4. Three- and Four-Engine Airplanes and ETOPS (continued)
Conclusions
(cont’d)
As described in earlier sections of ETOPS Explained, ETOPS twinjet flying
ranks among the very safest and most reliable of all flight operations. It is
the acknowledged state-of-the-art in long-distance air travel.
As airplane range capabilities continue to grow and flights over challenging
regions of the world become more common, the global aviation community
became increasingly aware that applying the reliability enhancements and
operational protections of ETOPS more broadly would lift the industry to
a higher and more uniform standard. To this end, the U.S. FAA enacted the
ETOPS rule of 2007. This rulemaking applies proven ETOPS protections
to the extended operation of three- and four-engine passenger airplanes as
well as to twinjets.
This section has briefly reviewed the impact of this rulemaking on affected
tri and quad operators who fly extended-diversion-time routes. Particular
attention was given to the issues of the ETOPS fuel reserve and cargo fire
suppression, since these are areas of potential cost concern to operators.
Also briefly examined were this rule’s exemptions (tri and quad passenger
planes are exempted from ETOPS maintenance requirements, and tri and
quad freighters are exempted entirely from ETOPS) as well as its delayedcompliance provisions for operator cost mitigation. The effect of the rule’s
type-design requirements on manufacturers was also described, as was the
development of the Boeing 747-8 Intercontinental passenger plane, which
will enter service in 2010 with 330-minute ETOPS certification.
The ETOPS rule of 2007 was addressed in this section only in the context
of three- and four-engine airplane operations. For a fuller discussion of this
rulemaking, see Section 2 of ETOPS Explained.
January 15, 2008
ETOPS Explained
4–10
Most Long-Range Flying Today is by Twinjet
Total Flights Over 3,000 nmi (~8 hrs) from August Official Airline Guide each year
Twin Total
10,000
737
757
767
777
A300
A310
A320
A330
Tri Total
Quad Total
DC10
L1011
MD11
707
DC8
Twins
747
A340
8,000
6,000
4,000
2,000
Tri's
Figure 4-1
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
0
1985
(from
August
OAG
each year)
Quads
1984
Scheduled
flights
per
week
ETOPS
Extended
Operations
Without ETOPS, FAR 121.161 limits 2–engine airplanes
to routes that remain within 1 hour flying time from an
airport, and passenger airplanes with more than two
engines to routes within 3 hours from an airport.
*
60
*
60
Alternate
Alternate
*
*
60
*
180
60
Departure
ETOPS portion
of flight
Destination
Legend:
*
Airports
Distance traveled in the specified minutes at one engine inoperative cruise speed
ETOPS flight path
Non–ETOPS flight path
Figure 4-2
*
120
When all airports are available, very few routes require more than 180-minutes,
which is the threshold of ETOPS for passenger airplanes with more than 2 engines.
78°N
Longyearbyen
Pituffik
Hatanga
Tiksi
Kangerlussuaq
Norlisk
Murmansk
Anadyr
Yakutsk
Fairbanks
Yellowknife
Reykjavik Stockholm
Iqaluit
Anchorage
Whitehorse
PetropavlovskBratsk
King Salmon
Kamcha
Goose Bay
Shemya
Churchill
Cold Bay
Khabarovsk
London
Gander
Seattle
Yuzhno-Sakhalinsk
Beijing
Sapporo
New York
Madrid
Seoul
Santa Maria
San Francisco
Tokyo
Moscow
Istanbul
Cairo
Magadan
Midway Is.
Delhi
Taipei
Bangkok
Male
Entebbe
Honolulu
Wake Is.
Guam
Hilo
Majuro
Medan
San Jose Cabo
Mexico City
Puerto Vallarta
Acapulco
San Jose
Tenerife
Dakar
Paramaribo
Monrovia
Diego Garcia
Jakarta
Harare
Johannesburg
Maputo
Durban
Mauritius
Nadi
Learmonth
Perth
Hobart
Sydney
Melbourne
Auckland
Easter Is.
Santiago
Georgetown
Luanda
Rio De Janeiro
Montevideo
Buenos Aires
Comodoro Rivadavia
Rio Gallegos
Christchurch
ETOPS Boundary
Recife
Hao Island
Rarotonga
Brisbane
Adelaide
60°S
Lima
Punta Arenas
747-400/PW4056 area of ETOPS applicability (based on 1520 nm)
Figure 4-3
Mount Pleasant
Libreville
Windhoek
Upington
Cape Town
Section 5
ETOPS Across the Atlantic
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Reviews the evolution of transatlantic flight operations.
„ Describes two trends that have largely transformed this air market.
„ Twinjet acceptance—twins flying under ETOPS rules (e.g., 777,
767) have largely displaced three- and four-engine jets (e.g., 747,
DC-10, L-1011) in services across the North Atlantic.
„ Market fragmentation—airlines are using smaller capacity jets
(e.g., 767, 777) to bypass traditional hubs with nonstop services
that directly link a very large and still growing number of Europe–
North America city pairs.
„ Identifies ETOPS as an enabling technology behind this profound
evolution of transatlantic air service patterns since 1985.
„ Shows that the U.S. ETOPS rule of 2007 will have very little effect
on today’s transatlantic air services and their subsequent evolution.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
A quarter century ago, transatlantic air travel relied on a small number of
“intercontinental gateway” airports. Almost all flights across the North
Atlantic departed and arrived through these continental gateways, so flying
from one continent to another generally required multiple flights.
In 1980, for example, traveling to Europe usually meant flying to New
York, boarding a jumbo jet to cross the Atlantic, and then taking a third
flight from London or Paris to one’s final destination. Today, in contrast,
people increasingly fly direct. Whether one is traveling from Cincinnati to
Switzerland, Orlando to Germany, or Philadelphia to the United Kingdom,
a single flight often gets us there.
What happened to make flying more direct? In the early 1980s, Boeing
introduced reliable, fuel-efficient twinjets that combined long range with
smaller passenger capacities. Flying under ETOPS rules, the 767—and later
other globe-spanning twinjets—let airlines fundamentally transform the way
traffic flows across the Atlantic Ocean. This profound transformation of air
service patterns is called “market fragmentation.”
February 15, 2008
ETOPS Explained
5–1
5. ETOPS Across the Atlantic (continued)
Transatlantic
evolution—
pre-WWII
The first scheduled passenger services across the North Atlantic were via
airship. Begun in the mid-1930s, those German services ended when the
hydrogen-filled Hindenburg exploded in the New York area after its first
Atlantic crossing of the 1937 season. Thirty-five passengers were killed,
ending the use of dirigibles for commercial air transport.
On June 28, 1939, a Boeing Model 314 Clipper
flying boat operated by Pan American Airways
made the world’s first scheduled transatlantic
passenger crossing by an airplane. Strictly for
the very wealthy, Pan Am’s pioneering Atlantic
service came to an end late in the year when interrupted by World War II.
WWII sets
the stage…
World War II greatly advanced the spectrum of flight-related technologies.
By the time this global conflict ended in 1945, it had
„ Fostered development of long-range transport planes like the Douglas
DC-4, Lockheed Constellation, and Boeing 377 Stratocruiser.
„ Greatly improved aerial navigation and aviation weather
forecasting systems and facilities.
„ Spurred the construction of military airfields worldwide.
Thus, the war created the global infrastructure that civil aviation used as
commercial flight operations resumed in the postwar era. Nowhere was this
truer than in the North Atlantic area of operations, where U.S. support of
Great Britain and prosecution of the war in Europe together had made the
North Atlantic a scene of large-scale military aviation activity during the
war years. By the time it ended, Atlantic flying was fairly routine.
Transatlantic
evolution—
post-WWII
Pan Am, TWA, American Overseas (acquired by Pan Am in 1950), and
Trans-Canada were the four North American pioneers of transatlantic air
travel in the immediate postwar era. From the other side of the Atlantic,
British Overseas Airways Corporation (BOAC),
SAS, KLM, Air France, Sabena, and Swissair
were all flying in this market by 1950. It was
the heyday of the great propeller airliners.
Unlike the North Pacific, which was then a quiet backwater (see Section 6),
the North Atlantic had the impetus of strong
economic activity and cultural ties between
North America and a reconstructing Europe.
Driven by economic growth on both sides of
the ocean, the North Atlantic soon became the
world’s most important and heavily traveled international air market.
February 15, 2008
ETOPS Explained
5–2
5. ETOPS Across the Atlantic (continued)
The jet age
On October 26, 1958, the Boeing 707 debuted over the North Atlantic. The
first truly successful jetliner, the 707 initiated a rapid transition to turbine
Propulsion that saw piston-powered airliners
phased rapidly out of first-line commercial
service. European carriers quickly adopted the
707 or its chief competitor, the Douglas DC-8,
which entered service in 1959. Together these
workhorse jetliners brought about a profound transformation, introducing
the jet speeds, comfort, and convenience to transatlantic air travel.
The 747
enters service
Like the 707, the Boeing 747—the world’s first “twin-aisle” jet—entered
commercial service across the North Atlantic
with Pan Am on January 22, 1970, flying New
York–London. TWA launched competing 747
services from New York the following month
(a United Airlines 747-100 is illustrated here).
In the early 1970s, two more widebody jets, The Douglas DC-10 and the
Lockheed L-1011 trijets, joined the 747 in North Atlantic service.
ETOPS begins
The next milestone in the evolution of the North Atlantic air market came
in 1985, when operators of the then-new Boeing
767 twinjet performed the world’s first ETOPS
flights as authorized by FAA Advisory Circular
AC 120-42. Those initial ETOPS flights quietly
launched the era of twinjet extended operations
on overwater and other routes that require flight beyond 60 minutes of an
alternate airport (see the Introduction and Section 1 of ETOPS Explained).
In addition to the twin-aisle 767, Boeing also introduced the single-aisle 757
twinjet to service in the early 1980s. Sharing the same flight deck and pilot
type rating as the 767, the 757 likewise became an ETOPS workhorse.
The 767
transforms
transatlantic
flying
As new technological capabilities arise, airlines put them to work in ways
that yield the greatest value for their customers, and thus for themselves
as well. In this way, new airplane capabilities can alter existing air service
patterns. Such was the case with the 767, whose availability let airlines
fundamentally transform their flight operations across the North Atlantic.
By combining long range and excellent economics with seating for about
half as many passengers as a 747, the 767 gave airlines the ability to
„ Fly shorter 747 routes twice as often for greater frequency of service.
„ Inaugurate nonstop services bypassing traditional hubs to directly link
smaller cities with insufficient travel demand for a 747-size airplane.
February 15, 2008
ETOPS Explained
5–3
5. ETOPS Across the Atlantic (continued)
Skeletal route
networks fill
out over time
In the 1980s, the world route network was skeletal in nature. Long-range
air travel relied on a small number of heavily traveled routes linking major
hubs serving as “gateways” to each of the world’s regions. Consequently,
intercontinental air travel generally required multiple flights.
Because the North Atlantic relied on just a handful of gateways, air travel
was frequently indirect. In 1980, for example, flying from Atlanta to Milan
required a domestic flight to New York, a transatlantic flight to London or
Paris, and then another domestic flight to get from Paris to Milan. Today,
in contrast, one can fly nonstop directly from Atlanta to Milan.
However, once long-range, smaller capacity jetliners like the 767 became
available, airlines began using them to flesh out their route structures with
new nonstop services that bypassed traditional hubs to directly link a far
larger number of cities on both sides of the Atlantic. The result of all this
bypass flying has been the fragmentation of the transatlantic air market.
Key benefits of
Atlantic market
fragmentation
Market fragmentation occurs when airlines exploit previously unavailable
airplane capabilities to pursue business strategies that let them offer greater
total value to their customers, the traveling public. The result across the
North Atlantic has been a profound, ongoing transformation of air service
patterns that benefits travelers by
„ Making flying more direct—secondary markets with insufficient
travel demand for a 747-size airplane can be profitably served with
smaller capacity airplanes like the 777, 767, 757, or 737 for more of
the direct flights that passengers strongly prefer.
„ Making flying more convenient—using smaller capacity jets, airlines
can fly existing routes more frequently, thereby offering business and
other travelers more choices and greater convenience in travel times.
„ Reducing congestion by “spreading out” the traffic—bypass flying
relieves pressure on the world’s busiest routes and hub airports for
fewer airport and system delays.
ETOPS and
Atlantic market
fragmentation
The North Atlantic was the undisputed domain of three- and four-engine
jets until ETOPS twinjets appeared on the scene in 1985 (fig. 5-1). By
1992, U.S. airlines were making more North Atlantic flights with ETOPS
twins than with three- and four-engine jets combined (fig. 5-2). By 1997,
twinjets were making half of all transatlantic flights. By 2006, they were
making more than three-quarters of all flights across the North Atlantic!
A comparison of transatlantic city pairs (i.e., cities linked through direct
transatlantic services) also illustrates the effects of market fragmentation
(fig. 5-3). In 1984, 421 city pairs enjoyed nonstop transatlantic services.
In 2007, the figure had risen to 1,128 city pairs, a 168-percent increase.
February 15, 2008
ETOPS Explained
5–4
5. ETOPS Across the Atlantic (continued)
ETOPS and
Atlantic market
fragmentation
(cont’d)
Chicago provides a good case study. In 1984, there was just one flight per
day from Chicago to Europe (fig. 5-4). This was a 747 that flew to London
where passengers transferred to destinations throughout Europe. By 2001,
Chicago had 36 daily 767 and 777 twinjet flights linking it directly with a
dozen destinations in Europe and the British Isles (fig. 5-5).
By 2006, however, ongoing market fragmentation saw Chicago and other
U.S. hubs increasingly bypassed by a continuing proliferation of nonstop
point-to-point services between a growing number of secondary cities in
North America and Europe. This bypass flying has actually reduced the
number of flights between European cities and Chicago, whose importance
as a hub has declined despite overall increases in transatlantic air travel.
ETOPS is
an enabling
technology
The conservative, evolutionary ETOPS program provides the regulatory
framework under which airlines can operate twinjets in extended service
(i.e., on routes that require flight beyond 60 minutes of an alternate airport).
ETOPS is thus a key “enabling technology” behind market fragmentation.
Enormously successful worldwide (see the Introduction and Section 1),
ETOPS benefits transatlantic and interregional Atlantic operators through:
„ Safety—data shows that ETOPS twinjet flying ranks among the very
safest of all flight operations; it is the state-of-the-art in long-haul travel.
„ Twinjet economics—ETOPS allows airlines to serve extended air
routes with twinjets, which cost less to operate than other jetliners.
„ Environmental preference—twinjets use less fuel so they create fewer
environmental emissions than three- or four-engine jets.
„ Market flexibility—because twinjets are more economical to operate
and they come in a greater variety of sizes, they let airlines
„ Profitably serve a greater number of the world’s population centers.
„ More closely match airplane capacity to actual travel demand.
„ Offer passengers more of the direct nonstop flights they prefer.
U.S. ETOPS
rule of 2007
February 15, 2008
On February 15, 2007, the U.S. Federal Aviation Administration (FAA)
enacted a new ETOPS rule. This regulatory updating of ETOPS
„ Codifies ETOPS for the first time directly in the U.S. federal
aviation regulations as befits such wide-scale flight operations.
„ Implements requirements updated according to the analysis
of facts and data compiled during more than two decades of
enormously successful ETOPS twinjet flying worldwide.
„ Applies many proven ETOPS requirements more broadly to further
protect the operation of three- and four-engine passenger jetliners on
routes with the potential for an extended diversion.
ETOPS Explained
5–5
5. ETOPS Across the Atlantic (continued)
U.S. ETOPS
rule of 2007
(cont’d)
Building on the outstanding reliability of long-range twinjets, this ETOPS
rule’s updated requirements ensure that existing safety is maintained while
creating for carriers the opportunity to fly properly configured and approved
twinjets on optimal flight routings between virtually any two cities on earth.
See Section 2 for a detailed look at the new U.S. ETOPS rule of 2007.
Different
ETOPS
thresholds
Note that under the 2007 rule, the threshold at which ETOPS requirements
apply differs for twinjets versus three- and four-engine passenger jetliners.
For twinjets, ETOPS applies—as was previously the case—on air routes
that at some point take the airplane beyond 60 minutes (at single-engine
cruise speed) of an airport. In contrast, for passenger jets with more than
two engines, ETOPS applies on routes that at some point take the airplane
beyond 180 minutes (at one-engine-inoperative cruise speed) of an airport.
2007 rule:
little impact
on Atlantic
operations
The ETOPS rule of 2007 has very little effect on existing transatlantic flight
operations for the simple reason that airplanes in the North Atlantic area of
operation never need to fly beyond 180 minutes of an airport. Therefore,
passenger operations flown with three- and four-engine jets are not subject
to the new rule’s requirements. As for existing ETOPS twinjet operations,
they remain essentially unchanged aside from minor updating of individual
requirements, such as the ETOPS fuel reserve requirement.
Carriers can also fly most of the South Atlantic with diversion times of 180
minutes or less. Consequently, it is only on routes linking South Africa with
southern South America that the new ETOPS rule comes into effect across
the Atlantic Ocean. Direct flights between the southern portions of these
two continents will take airplanes well beyond 180 minutes of an airport.
Therefore, all twinjets and all passenger jets with more than two engines are
subject to the 2007 rule’s provisions for beyond-180-minute ETOPS.
As stated, Section 2 of ETOPS Explained provides more information about
the U.S. ETOPS rule of 2007.
Conclusions
Transatlantic air travel has evolved to keep pace with economic growth on
both sides of the Atlantic Ocean. As this section has shown, the evolution
of this air market over seven decades was shaped primarily by technology.
This chapter has focused on flight-related technologies and ETOPS. Of
course, regulatory forces have also shaped transatlantic air travel. Bilateral
air-service agreements, the trend toward liberalization over recent decades,
and today’s “open skies” discussions are good examples. However, that
aspect of transatlantic market evolution is beyond this section’s discussion.
February 15, 2008
ETOPS Explained
5–6
5. ETOPS Across the Atlantic (continued)
Conclusions
(cont’d)
Initially, transatlantic flying used a skeletal route network that linked just
a few hubs serving as gateways to North America and Europe. As a result,
intercontinental travel a quarter-century ago often required three flights:
„ A domestic flight to one’s international gateway airport (e.g., New
York, London, Paris).
„ An ocean-spanning flight aboard a large widebody (747 or trijet).
„ Yet another flight on a smaller jet to one’s final destination.
Today, in contrast, the same trip often requires just a single flight. Using
fuel-efficient twinjets combining smaller passenger capacities with long
range, transatlantic air carriers are bypassing traditional hubs to bring direct
nonstop services to a large and still growing number of cities on both sides
of the Atlantic Ocean. This proliferation of point-to-point nonstop services
has transformed transatlantic air service patterns in a trend called bypass
flying or market fragmentation.
ETOPS is an enabling technology behind market fragmentation worldwide.
First performed in 1985, ETOPS provides the global regulatory framework
under which airlines fly long-range, smaller capacity twinjets on routes that
at some point take the airplane beyond 60 minutes of an airport. The safety,
reliability, efficiency, and varied passenger capacities of long-haul twinjets
like the 767, 777, or 787 Dreamliner allow airlines to
„ Offer more flight frequencies in existing air markets.
„ Inaugurate new point-to-point services on routes with insufficient
travel demand for a 747-size or larger airplane.
As the North Atlantic market’s evolution shows, ETOPS gives air carriers
the freedom to pursue alternative business strategies that offer passengers
greater total value through more choice and convenience in travel times as
well as more of the direct nonstop flights they strongly prefer.
Passage of the U.S. ETOPS rule of 2007 has very little effect on existing
transatlantic flight operations or this market’s future evolution. The reason
is that airplanes flying the North Atlantic never fly beyond 180 minutes of
an airport.
Airlines can also fly most of the South Atlantic with diversion times of 180
minutes or less. The exception would be flights between South Africa and
southern South America. To fly these routes, some twinjets and three- and
four-engine passenger jetliners may have to operate under the requirements
of the ETOPS rule of 2007’s provisions for beyond-180-minute ETOPS.
February 15, 2008
ETOPS Explained
5–7
Boeing Twins Have Changed the World
North Atlantic Air Traffic Patterns, U.S. Airlines - As of August 2007 OAG
1200
Boeing Twins
757, 767 and 777
1000
U.S. to
Europe:
weekly
800
non-stop
frequencies,
one way
600
400
Tri's L1011, MD11, and DC-10 Airbus Twins
A300, A310,
and A330
Quads - 747, DC-8,
707 and Concorde
200
0
'77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07
Figure 5-1
OAG-NA-US1
Twins Fly More than 3 Times as Many North Atlantic
Flights as 3- & 4-Engine Airplanes Combined
As of August 2007 OAG
2200
Twins
(737, 757, 767, 777,
A300, A310, A320,
A330)
2000
U.S. to
Europe:
weekly
nonstop
frequencies,
one way,
U.S. and
European
airlines
1800
1600
1400
1200
Three- and four-engine airplanes
(DC-8, 707, 747, A340, L1011,
MD-11, DC-10 and Concorde)
1000
800
600
400
200
0
'77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07
Figure 5-2
OAG-NA-All1
Fragmentation Has Fueled Expansion in the Atlantic
1984
2007
421 city pairs
1,128 city pairs
•All unique transatlantic city pairs from August Official Airline Guide (OAG)
Figure 5-3
TBC-ET-0110/DH/CJ8-24-7
Market Evolution―U.S. Airlines
Few choices prior to the fragmentation produced by ETOPS
London
Chicago
1984 Chicago Gateway
1 U.S. flight each way daily | Trans World | 747
Historic Gateway
Figure 5-4
Market Evolution―U.S. Airlines
ETOPS has lead to Market Fragmentation
Glasgow ManchesterStockholm
Brussels
Amsterdam
Düsseldorf
Birmingham
Frankfurt
London
Paris
Zurich
Rome
Chicago
Historic Gateway
Scheduled Daily Flights
2001 Chicago Hub
36 U.S. flights daily | American/United | 767 & 777
Figure 5-5
Market Evolution―U.S. Airlines
Fragmentation spreads beyond hubs
In 2006, Chicago flights to Europe are down from 2001, but trans-Atlantic twin
flights are way up as more cities are serviced on both sides of the Atlantic, and
the market continues to fragment.
Glasgow ManchesterStockholm
Brussels
Amsterdam
Düsseldorf
Birmingham
Frankfurt
London
Paris
Zurich
Rome
2006 Fragmentation
Figure 5-6
Section 6
ETOPS Across the Pacific
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Reviews the evolution of transpacific flight operations.
„ Describes two trends that are today transforming this air market.
„ Twinjet acceptance—twins flying under ETOPS rules (e.g., 777)
are today displacing three- and four-engine jetliners (e.g., L-1011,
DC-10, early-model 747s) in services across the Pacific Ocean.
„ Market fragmentation—airlines are using smaller capacity jets
(e.g., 777) to bypass traditional hubs with nonstop services that
directly link a growing number of Asia–North America city pairs.
„ Shows that ETOPS is an enabling technology behind this profound
evolution of transpacific air service patterns.
„ Briefly reviews the effect of the U.S. ETOPS rule of 2007 on transpacific flight operations.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
Many individual air markets together comprise the transpacific air market:
Asia–North America, Asia–Hawaii, the Americas–Hawaii, the Americas–
Australia / New Zealand, and Hawaii–Australia / New Zealand. Among the
longest flights in the Pacific area of operations are those via North Pacific
air routes that link North America with Asia.
In the 1990s, the North Pacific was almost exclusively the domain of the
four-engine 747 and widebody trijets (the DC-10 / MD-11 and L1011). By
2000, the 777 and other long-haul twinjets flying under ETOPS rules had
begun claiming a growing share of this market’s traffic. In 2007, twinjets
account for 45 percent, of long-range North Pacific flights (fig. 6-1). This
trend will see twinjets dominate within the next few years.
Introduced to service in 1995, the 777 complements the 747 in transpacific
service and accounts for a fast-rising share of Asia–North America traffic.
The workhorse 777 let airlines directly link a rising number of city pairs on
both sides of the Pacific with point-to-point nonstop services. Airlines use
it and other intermediate-capacity ETOPS twinjets to
„ Increase the number of flights on existing routes.
„ Open new routes with insufficient travel demand for a 747-size airplane.
February 15, 2008
ETOPS Explained
6–1
6. ETOPS Across the Pacific (continued)
Overview
(cont’d)
Market fragmentation is today fundamentally transforming transpacific air
service patterns in a way that parallels the fragmentation already observed
in the transatlantic air market (see Section 5). As a result, travelers today
„ Fly nonstop across the Pacific to a growing number of destinations.
„ Enjoy greater choice and convenience in departure and arrival times.
Transpacific
evolution—
pre-WWII
The Pacific Ocean was first conquered by air in October 1931 when two
Americans flew a small, single-engine Bellanca monoplane named Miss
Veedol from Japan to Washington State in 41 hours.
Commercial transpacific air travel began four
years later when Pan American World Airways
pioneered ocean-spanning services with flying
boats called “flying clipper ships.” The Martin
M-130 China Clipper performed history’s first
transpacific passenger flight in 1935. Departing from San Francisco Bay
on November 22, it island-hopped to the Philippines via Hawaii, Midway,
Wake, and Guam. Its passengers arrived in Manila after just 6 days and a
total flying time of 59 hours, 48 minutes.
On October 23, 1936, the Philippine Clipper—another M-130—flew on to
Hong Kong, thereby completing the first-ever passenger flight between the
continents of Asia and North America. World War II interrupted Pan Am’s
pioneering services, which by then stretched as far as New Zealand.
Although highly visible, those romantic flying-boat operations were the
antithesis of airline travel as we understand it today. Instead of serving
the masses, they catered exclusively to top executives and the very wealthy.
Everyone else in those days traveled between continents by ocean liner.
Transpacific
evolution—
post-WWII
World War II accelerated the development of long-range transport planes.
For example, the Douglas DC-4 and Lockheed Constellation both first flew
as military transports during the war. WWII also fostered the construction
of military air bases around the world. These former military airfields provided a ready-made global infrastructure for commercial flight operations
in the postwar era, eliminating the need for flying boats.
Transpacific air travel—this time with land planes—resumed in 1947 when
Pan Am and Northwest Airlines both inaugurated
Boeing 377 Stratocruiser services between North
America and Asia via Tokyo. No airliner back in
the propeller era had sufficient range capability to
fly nonstop between the United States and Japan,
so a “technical stop” for refueling was required in Hawaii or Alaska.
February 15, 2008
ETOPS Explained
6–2
6. ETOPS Across the Pacific (continued)
Transpacific
evolution—
post-WWII
(cont’d)
Japan Airlines entered the transpacific market in 1954 with Douglas DC-6B
services that linked Tokyo with San Francisco.
JAL introduced the DC-7C “Seven Seas,” the
last of the propeller airliners, two years later.
At that time, only a half-dozen airlines in the
world flew the Pacific, which was only just
beginning to show hints of the tremendous growth that would occur as
Japan rebuilt its powerhouse economy, traded with North America, and
invested regionally to spur growth throughout Asia Pacific.
The jet age
and nonstop
Pacific services
Over the decades, one of the most dramatic trends in commercial aviation
has been the ongoing increase in airliner range capabilities. Because of the
vast scale of the Pacific Ocean, airplane range has played a defining role in
the evolution and development of transpacific flight operations.
Jetliners began replacing propeller types in transpacific service at the start
of the 1960s. Like their piston-powered predecessors, those early jetliners
lacked sufficient range to fly the North Pacific nonstop, so a technical stop
for refueling remained necessary in either Alaska or Hawaii.
This situation finally changed in 1962, when airlines inaugurated nonstop
jet services between San Francisco and Tokyo using Boeing 707-320Bs.
Even after this key milestone, however, the vast scale of the Pacific Ocean
remained a challenge. Many key Asia–North America city pairs remained
too far apart for nonstop air services.
The 747—
workhorse
of the Pacific
Placed into service in 1970, the Boeing 747 combined a large capacity with
exceptional range capability. This four-engine airplane quickly established
itself as the airliner of choice for transpacific services. The degree to which
it has predominated in the Pacific is difficult to overstate.
So completely did the 747 come to dominate long-haul travel that in 1990
virtually all flights beyond 6,000 nautical miles were being made by 747.
At key Asian hubs, 747s sometimes appeared to be almost as numerous as
single-aisle 737s are at U.S. airports. JAL, ANA, Singapore, Thai, Cathay
Pacific, Korean, Asiana, Qantas, EVA, China Airlines, Air China, and PAL
are just some of the Pacific region’s many 747 operators.
To date, Boeing has delivered nearly 1,400 747s. By far the world’s largest
operator of the type is JAL, which has taken delivery of almost 100 747s
since 1970. In 2007, JAL had 64 747s in its fleet.
The 1989 introduction of the 747-400 family gave transpacific operators a
major boost in terms of payload/range and economics. Another is in the
works with today’s 747-8, which is scheduled to enter service in late 2009.
February 15, 2008
ETOPS Explained
6–3
6. ETOPS Across the Pacific (continued)
Twins take
the lead in
the Pacific
During the 1990s, long-range, smaller capacity jets became available as an
alternative to the 747. The Boeing 767 initiated Hawaii services in 1990
(Air Canada) and the 757 in 1992 (Canada 3000). In 1993, the 767 began
flying between Vancouver and Tokyo (Canadian Airlines International).
But it is the Boeing 777 twinjet that is transforming transpacific flying.
Placed into service in 1995, the 777 twinjet family offers exceptional fuel
efficiency, great range, and multiple size capacities. North Pacific carriers
have been quick to exploit the newfound capabilities this series provides,
as confirmed by today’s rapidly evolving transpacific air service patterns.
As late as 1998, three- and four-engine jets flew 92 percent of transpacific
flights and twinjets just 8 percent. By 2002, twinjets were making half of
all transpacific flights. In 2007, twins account for 65 percent—or almost
two-thirds—of transpacific flights (fig. 6-2).
The 777—
designed for
Pacific ETOPS
The Boeing 777 was designed with transpacific flying in mind. It offers
the greatest range of any airplane now in service or under development.
In a typical three-class layout, the 777-200 carries about 300 passengers
and the 777-300 carries about 365 (by comparison, the 747-400 carries
about 416). The 777 family consistently demonstrates dispatch reliability
above 99 percent, making it the world’s most reliable twin-aisle jetliner.
Designed from the outset for ETOPS, the 777 pioneered “early ETOPS”
and entered service in 1995 with “out of the box ETOPS” (see Section 1).
By March 2007, 608 777 twinjets were flying ETOPS with 32 operators
worldwide.
The 777 family is currently certified for 180-minute ETOPS. It is planned
that some 777 versions will be certified for 330-minute ETOPS as provided
for by the U.S. ETOPS rule of 2007. See below in this section for more
about this 2007 rulemaking, which is described in detail in Section 2.
Air service
patterns evolve
with technology
Long-range jetliners like the 747-400 and 777 are the backbone of global
air commerce. Technology has shaped transpacific flight operations by
„ Providing jet transports with sufficient range to fly the Pacific nonstop
(e.g., 747-400, 777, 787 Dreamliner) and perform shorter ETOPS
missions within this region (e.g., 767, 757, Next-Generation 737).
„ Bringing to market smaller capacity jetliners in recent years that
can fly as far as or farther than the 747-400 (e.g., 777, 787).
As new technological capabilities emerge, airlines apply them in ways that
yield the greatest value for their customers and thus for themselves as well.
In this way, new airplane capabilities can alter air service patterns.
February 15, 2008
ETOPS Explained
6–4
6. ETOPS Across the Pacific (continued)
Airline route
networks fill
out over time
Two decades ago, the global network was skeletal in nature. International
travel relied on a relatively small number of “gateway hubs” in each of the
world’s regions. Long-range air travel was generally via these gateways,
so flying from one continent to another usually required multiple flights.
In 1985, for example, flying from Dallas to Osaka meant taking a domestic
flight to the West Coast, boarding a large twin-aisle jetliner to cross the
Pacific Ocean, and then taking another domestic flight or perhaps boarding
a train to travel from Tokyo to Osaka. Today, in contrast, a single nonstop
flight from Dallas to Osaka aboard a twin-aisle 777 is all that is required.
What happened? Smaller capacity ETOPS twinjets were introduced that
can fly long distances and profitably serve secondary air markets as well as
primary ones. Over time, airlines have used these long-range ETOPS twins
to flesh out their once-skeletal route structures with additional services that
bypass traditional gateway hubs to directly link a much larger and growing
number of population centers on both sides of the Pacific. The result of this
bypass flying is the fragmentation of the transpacific air market (fig. 6-3).
This North Pacific market fragmentation resembles the fragmentation that
has already occurred in the North Atlantic market (see Section 5), except
that the North Pacific is at an earlier stage in its evolution. As of 2007,
ETOPS twinjets account for 45 percent of all flights across North Pacific.
That was the case back in 1996 for the North Atlantic, where today ETOPS
twins make 77 percent of all flights.
Boeing did not set out to transform long-range travel patterns. We simply
built better, more capable airplanes and the world’s airlines did the rest.
Key benefits of
Pacific market
fragmentation
As stated, the North Pacific air market is fragmenting because airlines are
exploiting previously unavailable airplane capabilities to pursue business
strategies that offer greater value to the traveling public. This increased
value stems from these demonstrated benefits of market fragmentation:
„ More direct flights—secondary markets with insufficient travel
demand for large airplanes can be profitably served using smaller
capacity twinjets, for more of the nonstops travelers strongly prefer.
„ Greater convenience—long-range, smaller capacity jets let airlines
fly existing routes more often, offering business and other travelers
greater choice and convenience in departure and arrival times.
„ Reduced congestion—pressure is relieved on the world’s busiest
airports and routes because traffic is spread across more flight times
and more airports.
See the discussion below in this section for specific examples and insights
into the ongoing fragmentation of the Pacific air market.
February 15, 2008
ETOPS Explained
6–5
6. ETOPS Across the Pacific (continued)
Changes in this
market over the
last decade
Despite the Asian financial crisis of the mid-1990s, reduced travel demand
in the wake of the terrorist attack of September 11, 2001, and the SARS
outbreak of 2003, during the 10-year period from 1997 through 2006:
„ The number of flights within Asia-Pacific rose by 70 percent.
„ The number of airport pairs that have direct air service within
Asia-Pacific increased by 12.5 percent.
„ The number of airport pairs that have direct transpacific air service
increased by 47 percent, rising from 94 to 138.
„ Average airplane size on transpacific routes declined by 7.5 percent.
As the above shows, a rising number of cities on both sides of the Pacific
Ocean, and within Asia-Pacific, are gaining direct services. This ongoing
proliferation of nonstop flights reduces pressures on the region’s busiest
hubs as they are bypassed. Except in isolated instances, this fragmentation
of the Pacific air market undercuts the Asia-Pacific region’s requirement
for airplanes bigger than the 747. The availability of more capable and
economical mid-size airplanes, and rising operational flexibility through
ongoing air service liberalization, has fostered heightened competition for
more choices and greater convenience in Asia-Pacific air travel.
The Boeing 2007 Current Market Outlook forecasts that Asia-Pacific’s air
carriers will require 8,350 new airplanes of all sizes over the next 20 years
(2007–2026). Of these, 2,530 will be intermediate-capacity jetliners like
the 787 and 777. Just 500 will be jets the size of a 747 or larger.
ETOPS is
the enabling
technology
ETOPS is the global regulatory framework under which airlines fly twinengine, turbine-powered airplanes on routes that take the twinjet more than
60 minutes from an alternate airport. Thus, ETOPS is the key “enabling
technology” that allows market fragmentation to occur.
The hugely successful ETOPS program (see the Introduction and Section 1)
benefits transpacific and inter-regional Pacific operators through:
„ Leading safety—data shows that ETOPS ranks among the very safest
of all flight operations; it is the state-of-the-art in long-range air travel.
„ Environmental preference—twinjets burn less fuel than do three- or
four-engine jets so they create fewer environmental emissions.
„ Twinjet economics—ETOPS lets airlines fly optimal routings with
twinjets, which cost less to operate than other jetliners.
„ Market flexibility—because twins are more economical and come in
a greater variety of sizes, they let airlines
„ More closely match airplane capacity to actual travel demand.
„ Profitably serve a greater number of the world’s population centers.
„ Link more cities with the direct nonstop services passengers prefer.
February 15, 2008
ETOPS Explained
6–6
6. ETOPS Across the Pacific (continued)
Early Pacific
experience
set the stage
for ETOPS
Before the ETOPS program began in 1985 (see Section 1), some airlines in
the South Pacific were already performing limited extended-diversion-time
operations with twinjets. Those pioneering pre-ETOPS operations gave the
global aviation industry its first experience with flying two-engine jets on
routes that at some point take the twinjet more than 60 minutes (at singleengine cruise speed) from an available alternate airport. That early Pacific
experience with extended operations included:
„ New Zealand–Fiji services inaugurated in the early 1970s using
BAC 111s, and later 737s, that took the airplane 83 minutes from
the nearest alternate airport (Air New Zealand, Air Polynesia).
„ Inter-island services that Air Nauru inaugurated in the early 1980s,
which covered much of the South Pacific.
Also before ETOPS began in 1985, five South Pacific operators—Air India,
Air Lanka, Thai Airways International, Singapore Airlines, and Malaysia
Airline System—were flying twins across the Indian Ocean in services that
yielded additional experience on twinjet overwater use, although this flying
may not have exceeded the 60-minute operating restriction on two-engine
airliners (see Section 3 for information about the 60-minute rule of 1953).
By 2006, well over 1 million ETOPS flights had been logged in the South
Pacific region, including between Australia–New Zealand and Southeast
Asia. In fact, the South Pacific accounts for about one-fourth of all the
ETOPS flights ever made.
Hawaii–
mainland
fragmentation
Hawaii–North American mainland flight operations provide another good
example of fragmentation in the Pacific region. In the mid 1990s, widebody
jetliners and just one single-aisle jet—the 757 with about 200 passengers—
linked North America with Hawaii. Today, Next-Generation 737s with
180-minute ETOPS capability also serve this busy air market in a growing
number of nonstop mainland-Hawaii services that bypass traditional hubs.
Los Angeles, San Francisco, and Vancouver are the mainland gateways
through which most traffic passes between North America and Hawaii.
But in 2000, a dramatic change began quietly when Aloha Airlines—up
until then, an inter-island Hawaiian operator—launched pioneering NextGeneration 737 services connecting secondary airports in North America
with locations in Hawaii.
By 2007, six different operators were flying Next-Generation 737 ETOPS
services that connected 62 Hawaii–North America city pairs. In all, 28
Boeing operators now fly 777, 767, 757, or Next-Generation 737 twinjets
between 334 Hawaii-North American city pairs. Thus, a great many more
mainland cities enjoy direct services to more destinations in Hawaii than
just ten years ago.
February 15, 2008
ETOPS Explained
6–7
6. ETOPS Across the Pacific (continued)
Hawaii–
mainland
fragmentation
(cont’d)
What allowed this fragmentation to occur in the Hawaii–North America
segment of the overall transpacific air market? As the above suggests, the
answer is the Next-Generation 737 family of advanced twinjets, which:
„ Offers 180-minute ETOPS capability, which is required for twinjets
to operate in this air market.
„ Combines four model sizes with excellent field performance and
exceptional range capability, giving airlines the flexibility to bypass
hubs with direct services between a large number of smaller airports.
The Next-Generation 737 is the world’s most reliable commercial transport.
Introduced to service in 1997, it pioneered 180-minute ETOPS for small
jetliners, a capability not previously available in airplanes smaller than the
757. Airlines were quick to exploit these qualities and its long range, as
today’s Hawaii–North America market fragmentation shows.
Transpacific
operational
challenges
Of course, the Pacific region’s most demanding operations are nonstop
flights that span the entire ocean. These today-routine operations contend
with one or both of the following region-specific challenges:
„ The vast scale of the Pacific Ocean itself.
„ The temperature and weather extremes sometimes encountered on
North Pacific routes, especially far-northerly “great circle” routes.
Fortunately, the Pacific has ample alternate airports in case a flight needs
to divert. The availability of these en route alternates enhances safety for
all operators, regardless of how many engines their airplanes may have.
A growing need
for regulatory
updating
Rising jetliner range capabilities and ongoing market fragmentation have
together led to flights that increasingly traverse remote areas of the world
where an airplane is at times far from an airport. Today, flights of a dozen
hours are common and—particularly in nonstop transpacific operations—
flights of 18 or more hours are becoming routine.
Of course, all airplanes that fly these and other extended-diversion-time
routes must contend with similar operating challenges in terms of weather,
terrain, and limitations in navigation and communications infrastructure.
Given this common operating environment, and the fact that all jetliners—
twins, tris, and quads—are enormously safe, the global aviation community
increasingly realized in the 1990s that a common operating environment
was desirable, and that the proven protections and enhancements of ETOPS
could benefit all extended operations, not just those involving twinjets.
In 2000, the U.S. FAA embarked on a collaborative regulatory updating
with global participation that culminated in the ETOPS rule of 2007.
This rulemaking is described briefly below in the context of this chapter.
February 15, 2008
ETOPS Explained
6–8
6. ETOPS Across the Pacific (continued)
The U.S. ETOPS
rule of 2007
On February 15, 2007, the U.S. Federal Aviation Administration (FAA)
enacted its ETOPS regulatory updating. This ETOPS rule
„ Codifies ETOPS for the first time directly in the U.S. federal
aviation regulations as befits such wide-scale flight operations.
„ Implements requirements updated according to the analysis
of facts and data compiled during more than two decades of
enormously successful ETOPS twinjet flying worldwide.
„ Applies proven ETOPS requirements more broadly to enhance
the operation of three- and four-engine passenger jetliners on
routes with the potential for an extended-duration diversion.
„ Provides for ETOPS beyond 180 minutes and makes the design
capabilities of the airplane type (airplane-engine combination)
the basis for establishing that type’s maximum diversion authority.
Building on the outstanding reliability of long-range twinjets, this ETOPS
rule’s updated requirements ensure that existing safety is maintained while
creating for carriers the opportunity to fly properly configured and approved
twinjets on optimal flight routings between virtually any two cities on earth.
See Section 2 for a detailed examination of the U.S. ETOPS rule of 2007.
Different
ETOPS
thresholds
Under the 2007 rule, the threshold at which ETOPS applies differs for twins
versus tris and quads. For twins, ETOPS applies—as was previously the
case—on routes that at some point take the airplane beyond 60 minutes
(at single-engine cruise speed) of an airport. For passenger jetliners with
more than two engines, in contrast, ETOPS applies on routes that at some
point take the airplane beyond 180 minutes (at one-engine-inoperative cruise
speed) of an airport. Consequently, it is only at diversion authorizations
above 180 minutes is ETOPS flown by tris and quads as well as by twins.
Little impact
on current
operations
Passage of the ETOPS rule of 2007 has relatively little effect on existing
Pacific-region operations with three- and four-engine passenger airplanes.
The reason is that the great majority of transpacific routes do not take an
airplane beyond 180 minutes of an alternate airport, which is the threshold
at which ETOPS applies to tris and quads. Thus, most current transpacific
passenger operations by tris and quads are not ETOPS flights.
For affected Pacific-region carriers whose tri or quad extended-diversiontime operations are now subject to ETOPS, the 2007 rule mitigates costs
by specifying delayed compliance periods for certain rule requirements.
For example, a 6-year grace period is provided to let operators upgrade
their airplanes’ cargo fire suppression systems during regularly scheduled
airplane heavy maintenance cycles.
(Continued)
February 15, 2008
ETOPS Explained
6–9
6. ETOPS Across the Pacific (continued)
Little impact
on current
operations
(cont’d)
The 2007 rule also mitigates costs for current operators by exempting their
three- or four-engine passenger jetliner fleets from the requirement for an
ETOPS maintenance program. Nevertheless, the FAA endorses the higher
reliability afforded by proven ETOPS maintenance practices. It should be
noted that some tri and quad operators have voluntarily instituted ETOPS
maintenance programs even though it was not required of them.
For all-cargo operators, the 2007 rule brings no changes to their existing
freight operations because tri and quad main-deck freighters are exempted
from the rule (in contrast, twinjet freighters are subject to ETOPS).
Cost varies
from one
operator to
the next
It is difficult to broadly assess the cost impact of the 2007 ETOPS rule on
Pacific-region operators who fly three- or four-engine ETOPS because
„ Each operator’s situation differs in terms of route structure, fleet
mix, operating challenges, and internal airline policies.
„ It is not possible to state how or to what degree the benefits of
ETOPS translate into direct savings for the operator.
Consequently, the most that one can say with certainty about the economic
impact of the 2007 rule is that its effect varies from one affected Pacific
operator to the next. See Section 14 for more about ETOPS economics.
Conclusions
The evolution of commercial flight operations across the Pacific has largely
been shaped by economic forces (e.g., economic growth, trade policies) and
technology (e.g., increased airplane performance and propulsion reliability).
Air service agreements negotiated between nations have also shaped this air
market, of course, but they lie beyond the scope of this section’s discussion.
Transpacific flying began with a skeletal route network linking just a very
few hubs that served as gateways to different nations and regions. As a
result, intercontinental air travel a quarter-century ago often required three
flights: a domestic flight to the international gateway, a flight across the
Pacific, and yet another domestic or regional flight to the final destination.
Today the same trip often requires just a single flight.
Fuel-efficient twinjets like the 787 Dreamliner and 777 combine long range
with smaller passenger capacities. Pacific operators use this combination to
bypass traditional hubs with point-to-point services directly linking a rising
number of city pairs. This bypass flying is transforming air service patterns
and filling out the North Pacific route network in particular in a profound
trend called market fragmentation. Although the North Pacific market is at
an earlier stage of development than the North Atlantic market, its current
evolution parallels the fragmentation that has already been observed across
the North Atlantic (see Section 5).
(Continued)
February 15, 2008
ETOPS Explained
6–10
6. ETOPS Across the Pacific (continued)
Conclusions
(cont’d)
ETOPS is an enabling technology behind market fragmentation. Pacific
operators use ETOPS to fly long-haul, intermediate-capacity jetliners in
extended operation on routes that at times take the airplane far from an
alternate airport. The smaller capacities and fuel efficiency of Boeing
twinjets in particular let airlines
„ Increase flight frequencies in existing air markets.
„ Inaugurate new point-to-point services on routes with insufficient
travel demand for a 747-size airplane.
In this way, ETOPS gives air carriers the flexibility to pursue alternative
business strategies that offer their customers greater value in terms of
increased choice, greater convenience in travel times, and more of the
direct nonstop services that passengers strongly prefer.
Performed since 1985, ETOPS twinjet flying is the state-of-the-art in longdistance air travel. It sets the standard for safe, reliable flight operations
(see the Introduction and Section 1 of ETOPS Explained). To lift the entire
industry to a higher and more uniform level, the U.S. FAA enacted the
ETOPS rule of 2007, which for the first time applies ETOPS more broadly
to also embrace the extended operation of tri and quad passenger jetliners.
Building on the outstanding reliability of long-range twinjets, this ETOPS
rule’s updated requirements ensure that existing safety is maintained while
creating for carriers the opportunity to fly properly configured and approved
twinjets on optimal flight routings between virtually any two cities on earth.
Passage of the 2007 ETOPS rule has relatively little effect on air carriers
who currently fly three- and four-engine airplane passenger services in the
Pacific. The reason is that the great majority of transpacific routes do not
take the airplane beyond 180 minutes of an alternate airport, which is the
threshold at which ETOPS applies to tris and quads. As for tri and quad
freighter operators, they are unaffected by the 2007 rule because it entirely
exempts all-cargo operations with freighters having more than two engines.
The ETOPS rule of 2007 mitigates costs through compliance grace periods
for meeting key requirements, and by exempting three- and four-engine
passenger airplane fleets from meeting ETOPS maintenance requirements.
The specific economic impact of this rule is difficult to quantify and varies
from one affected operator to the next.
February 15, 2008
ETOPS Explained
6–11
Long-Range North Pacific Flights
The Advantages of Twins Acknowledged by a Dramatic Shift in the Marketplace
800
700
Quads
and Tri's
600
500
All North Pacific flights are
considered long-range. By
2007, 45% of all North Pacific
flights were flown by twins.
400
Twins
300
200
100
Figure 6-1
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
0
1992
Scheduled
passenger
flights per
week from
the USA and
Canada
(including
Hawaii but
excluding
Alaska)
across the
North Pacific
to Asia as
counted in
the Official
Airline Guide
in August
of each year.
Twins Dominate Trans-Pacific Flights
1992 - 2007
Twins
1200
1000
800
One-way
passenger
flights
per week
600
Quads and
Tri's
400
200
0
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
From August Official Airline Guide (OAG) each year. Non-stop passenger flights from America (North, Central or South, but
excluding Alaska) to Hawaii or Asia or Australia/New Zealand. And from Hawaii to Asia or Australia/New Zealand.
Figure 6-2
Trans Pac
Fragmentation Has Fueled Expansion in the Pacific
1984
2007
51 city pairs
138 city pairs
•All unique transpacific city pairs from August Official Airline Guide (OAG)
Figure 6-3
TBC-ET-0111DH/CJ8-30-7
Section 7
Polar Flying and ETOPS
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Discusses flight operations within the North and South Polar regions
where additional operational requirements apply.
„ Note that these requirements apply at all times to all airplanes within
these areas, regardless of number of engines or actual diversion time.
„ If ETOPS is being performed, polar requirements apply in addition
to the ETOPS requirements.
„ Because of the different ETOPS applicability thresholds, twinjets
require ETOPS to fly North Polar routes whereas three- and fourengine jetliners generally do not.
„ All jetliners will need ETOPS to operate in the South Polar region
because it is larger and has fewer alternate airports (as yet, there
are no commercial flight operations in the South Polar region).
„ Reviews the evolution of polar flight operations and distinguishes
between these two types of far-northerly flying:
„ Polar flying—flight operations in the North Polar Region itself
where special requirements apply (also called cross-polar flying).
„ Transpolar flying—flight operations conducted north of the Arctic
Circle, which is at 66º N latitude, but not actually within the North
Polar region itself, which begins at 78º N latitude.
„ Describes the 2001 opening of the four Russian commercial air routes
across the North Polar region that most polar flying relies upon.
„ Examines the effects of the U.S. ETOPS rule of 2007 on polar flying.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s table of contents.
Overview
Commercial airliners have been flying transpolar routes that extend above
the Arctic Circle (i.e., north of 66º N latitude) since well before the jet age.
Today, long-range jetliners routinely fly in this northern region. Nonstop
flights between Europe and the West Coast of North America offer good
examples as those “great circle” operations cut north of the Arctic Circle.
In 2001, airlines began using new routes that actually cross the North Polar
region itself. Four cross-polar route tracks link eastern and interior parts
of North America with Asia, offering attractive shortcuts that save time and
February 15, 2008
ETOPS Explained
7–1
7. Polar Flying and ETOPS (continued)
Overview
(cont’d)
fuel compared to the less direct routings used in the past. Polar flying also
reduces environmental emissions because less fuel is consumed. In some
cases, these polar routes allow nonstop services between Asian and North
American cities that could otherwise not enjoy direct air links.
Although the requirements for North or South Polar flight operations are
not ETOPS, the U.S. Federal Aviation Administration (FAA) has codified
them within the 2007 rulemaking as described below. These requirements
apply at all times to all affected airplanes within these regions. On polar
flights that are ETOPS, they apply in addition to the ETOPS requirements.
Definitions:
polar versus
transpolar
operations
The term polar operations usually denotes commercial flight operations via
the four available polar air routes that extend across the North Polar region
itself to link Asia with North America. Also sometimes called cross-polar
operations, intercontinental flying via these four routes is relatively new.
A broader definition of polar operations is any and all affected commercial
flying that at some point extends north of 78º N latitude or south of 60° S
latitude. In the U.S. federal aviation regulations, CFR Part 121, Appendix
P, Section III, Approvals for operations whose airplane routes are planned
to traverse either the North Polar or South Polar Areas, governs operations
within these areas.
In contrast, the term transpolar operations denotes flying on routes that at
some point extend north of the Arctic Circle (66º N latitude) but not so far
north as to enter the North Polar Area itself (78° N latitude). Transpolar
flying has a long history and is common. Many of today’s “great-circle”
routes cut north of the Arctic Circle at some point during the flight.
An important
distinction…
As stated, the term polar operations does not embrace all far-northerly
flying conducted above the Arctic Circle (66º N latitude), but rather just
those flights that enter the North or South Polar Areas (north of 78º N
latitude and south of 60° S latitude).
Transpolar
flying began
in the propeller
airliner era
Scheduled commercial flying north of the Arctic Circle began back in 1956
when SAS inaugurated Douglas DC-6B services between Copenhagen and
Los Angeles with a refueling stop in Greenland. Those pioneering pistonera operations (the DC-6B was a propeller airliner) show that far-northerly
flying has been routine since before the jet age.
In the half-century since that inaugural transpolar flight, the global aviation
industry has accumulated vast experience with transpolar flight operations.
The traveling public has long considered them entirely safe and routine.
February 15, 2008
ETOPS Explained
7–2
7. Polar Flying and ETOPS (continued)
Polar Routes
opened in 2001
In February 2001, four Russian polar routes became available to airliners.
From west to east, these routes are Polar 1, Polar 2, Polar 3, and Polar 4.
Polar 1 aligns over the North Pole between North America and the Indian
Subcontinent. Polar 2, Polar 3, and Polar 4 align between North America
and Southeast Asia. Many thousands of airline flights have used these new
polar tracks since 2001, and hundreds more do so every month (fig. 7-1).
Because of the way the world’s continents align, the polar routes do not
benefit intercontinental operators flying to and from Europe.
Russia’s
key role in
polar flying
Russia played the most important role in instituting polar flying by:
„
Opening its vast airspace to international use in 1990.
„
Initiating collaborative discussions with the international community
in 1994 to establish polar route tracks through its territory.
In addition, Russia has made many airports available for diversionary use
as described in the Russian Aeronautical Information Publication (AIP).
Other factors
also support
polar flying
Polar flying emerged for many reasons. Among the other factors leading
to cross-polar flight operations being instituted are that
„
Airlines had long expressed interest in direct Asia–North America
links via the North Pole (Europe does not benefit from polar routes).
„
Long-range airplanes like the Boeing 747, 777, and 787 Dreamliner
offer sufficient payload / range capability to let airlines directly link
many Asian–North America city pairs via the polar routes.
„
The 747-8 builds further on the capabilities of the workhorse
747 family with greater range and greater fuel efficiency.
„
The 777 twinjet family offers greater range than any other
jetliner currently in service or now being developed.
„
The 787 Dreamliner’s combination of range, fuel efficiency,
and low operating costs offer polar and other operators new
flexibility to serve long, thin markets and link new city pairs.
Polar route
trial flights
Before the four polar routes opened for regular use in 2001, U.S. and Asian
airlines evaluated them with more than 650 demonstration flights made by
special arrangements with the Russian authorities. The first of these trial
flights took place on July 5, 1998, when a Cathay Pacific Airways 747-400
flew from New York to Hong Kong via the North Pole.
That first scheduled polar revenue flight is historic for two reasons. At its
conclusion, the Cathay 747-400 made the first official landing at Chek Lap
Kok, Hong Kong’s new international airport and Cathay’s new home base.
February 15, 2008
ETOPS Explained
7–3
7. Polar Flying and ETOPS (continued)
Benefits of
polar flying
The benefits of polar flying between North America and Asia include
„
Shorter flight times between many existing city pairs.
„
Reduced fuel consumption and environmental emissions.
„
Opportunities for new nonstop services between city pairs too widely
separated for direct air links via non-polar routings.
Examples of polar services today being flown are New York–Hong Kong,
Chicago–Hong Kong, and Singapore–New York. All three of these city
pairs can also be served less directly by non-polar routings, but at the cost
of higher fuel consumption, emissions, and travel time.
Sufficient
alternate
airports
Sufficient alternate airports are available to support north polar ETOPS.
On the North American side, airports already serving as North Atlantic
and North Pacific ETOPS alternates also support polar ETOPS.
On the Asian side of the world, Russia’s FAAR agreed in 1998 to make
information available on a large number of domestic airports that were
not previously listed in the AIP. The availability of these Russian airports
enhances safety for all carriers operating in the region, regardless of the
airplane flown or how many engines it has.
Information about Russia’s airports—including facilities, procedures, and
services—is available from the Russian Aeronautical Information Center of
Civil Aviation under the trade name Rossjepp. Airlines may subscribe to
Rossjepp through the IATA.
Alternate airports for South Polar operations are wider spaced and further
from routes. Longer diversion times are thus required for operations that
traverse the South Polar area. Long-range Boeing jetliners such as the
777, 787, and 747-800 will have optional 330-minute diversion authority
available that allows ETOPS throughout the South Polar operations area.
Alternate
airports were
assessed
In support of 777 polar ETOPS, Boeing assessed the capabilities of many
of Russia’s alternate airports in the period 1999–2001. Those inspections
assessed these airports’ facilities and evaluated their ability to support all
aspects of airplane diversions.
Experts from airlines and U.S. and Russian regulatory authorities joined
Boeing people for these on-site assessments. Among the capabilities they
evaluated were the availability of rescue and firefighting services (RFFS)
and facilities to safely accommodate stranded passengers and air crews.
Comprehensive reports describing the results of these North Polar–region
alternate airport evaluations are available on request to Boeing customers.
February 15, 2008
ETOPS Explained
7–4
7. Polar Flying and ETOPS (continued)
The 747-400
and 777
predominate
The 747-400 and 777 today account for almost all polar flying. Operating
under ETOPS rules, 777 twinjets have been in regular polar service since
March 2001. Here as elsewhere in the world, airlines are benefiting from
the leading efficiency, reliability, and safety of long-range twinjets.
ETOPS twinjets
on polar routes
Air carriers wanted the flexibility to fly all suitable airplane types on these
polar routes, the Boeing 777 included. The global aviation community
responded to this operator requirement with an effective collaboration that
saw polar ETOPS with 777 twinjets inaugurated in 2001.
Among the parties working to achieve this goal were the Federal Aviation
Authority of Russia (FAAR), the FAA, and other regulatory authorities;
the International Air Transport Association (IATA) and International Civil
Aviation Organization (ICAO); many airlines; Boeing; and the Russian /
American Coordinating Group for Air Traffic Control (RACGAT).
About transSiberian ETOPS
As stated, many air carriers had experience with far northerly operational
challenges prior to the inauguration of polar ETOPS. In October 1990, for
example, SAS began flying 767-300 twinjets across Siberia to Japan from
Copenhagen and Stockholm. Although the ETOPS route flown by SAS
across Siberia was not transpolar, since it approached the Arctic Circle at
its west end but did not cross it, it nevertheless yielded valuable experience
in extreme-cold-weather winter operations.
About TSRN
Building on those pioneering SAS services, the IATA has helped create a
Trans-Siberian Route Network (TSRN) linking major European and Asian
destinations. Unlike the SAS service, the TSRN does involve transpolar
flying because it includes routes that at some point loop north of the Arctic
circle. The most northerly point, on TSRN Route 1, extends to 75° 50' N.
About
FANSTAR
In a similar effort, British Airways and KLM have pursued FANSTAR, a
transpolar route that links Europe with Japan. Like the TSRN, FANSTAR
seeks to enhance the existing aviation infrastructure from Murmansk across
Siberia to the Russian Far East.
The U.S. ETOPS
rule of 2007
On February 15, 2007, the U.S. Federal Aviation Administration (FAA)
enacted a comprehensive new ETOPS rule that
„ Implements requirements updated according to the analysis of facts
and data compiled during more than two decades of enormously
successful ETOPS twinjet flying worldwide.
(continued)
February 15, 2008
ETOPS Explained
7–5
7. Polar Flying and ETOPS (continued)
The U.S. ETOPS
rule of 2007
(cont’d)
„
„
„
Applies ETOPS more broadly to also embrace the operation
of three- and four-engine passenger jetliners on routes with
the potential for an extended-duration diversion.
Provides for ETOPS beyond 180 minutes, and makes the design
capabilities of the airplane type (airplane-engine combination)
the basis for establishing that type’s maximum diversion authority.
Establishes different ETOPS applicability thresholds for twinjets
(beyond 60 minutes from an airport) versus three- and four-engine
jetliners (beyond 180 minutes from an airport).
Building on the outstanding reliability of long-range twinjets, this ETOPS
rule’s updated requirements ensure that existing safety is maintained while
creating the opportunity for compliant carriers to fly properly configured
and approved airplanes on optimal flight routings—including in the North
and South Polar regions—between virtually any two cities on earth for
which the airplanes have sufficient range.
See Section 2 for a detailed look at the U.S. ETOPS rule of 2007.
Polar flying
under the 2007
ETOPS rule
In the 2007 ETOPS rule, the FAA has also taken the opportunity to codify
several provisions that are not ETOPS but relate to it. Among these nonETOPS provisions are updated requirements for North and South Polar
operations that were first issued in 2001 as an FAA Policy Letter. That
FAA polar policy, as it was then known, has been incorporated with only
minor changes into the 2007 rule, which today provides a uniform process
for operators seeking polar route authority.
As stated, the North and South Polar regions embrace everything north of
78º N latitude and south of 60º S latitude respectively. Within these areas,
all affected airplanes—regardless of actual diversion time or how many
engines they have—must meet polar operational requirements. If the polar
flight is also an ETOPS flight, the polar requirements apply in addition to
the ETOPS requirements.
Twinjets are subject to ETOPS whenever they fly routes that take them
beyond 60 minutes of an adequate airport at single-engine cruise speed.
Consequently, North Polar flight operations by twinjets require ETOPS.
In contrast, three- and four-engine jetliners generally do not need ETOPS
to operate within the North Polar region because of their higher ETOPS
applicability threshold of 180 minutes from a suitable airport.
The situation is very different in the South Polar region. There all jetliners,
regardless of number of engines, will require ETOPS because of the much
greater area it encompasses, the higher ratio of water to land, and the proportionately greater distances between its fewer available alternate airports.
February 15, 2008
ETOPS Explained
7–6
7. Polar Flying and ETOPS (continued)
Specific polar
requirements
To operate within a polar region, an affected air carrier must
„ Have a special operational approval listed in its Operations
Specification document that spells out applicable policies
and procedures.
„ Identify in the Ops Spec document the en route alternate airports
on which these operations will rely.
„ Have current passenger recovery plans in place for these identified
diversion airports (all-cargo operators are of course exempted from
this requirement).
„ Implement a fuel-freeze strategy and appropriate procedures.
„ Ensure adequate communications capability.
„ Provide training on solar radiation hazards and other challenges
unique to polar operations.
„ Implement a minimum equipment list (MEL) that is specific
to these operations.
„ Have at least two cold-weather survival suits aboard the airplane
to protect crew members during any outside activities at diversion
airports where possible extreme weather conditions might prevail.
Note that in the case of this last polar requirement, the regulation allows
the FAA to relieve operators from having to carry cold-weather survival
suits during summer months.
About weather
and airport
availability
ETOPS rules require that weather conditions at the designated alternate
airports must meet specified minimums before airplanes may be dispatched.
To determine how frequently these proposed polar alternates are effectively
closed, meteorological data from 1986 through 1995 was analyzed. That
study confirmed that a sufficient number of alternate airports will always
be available. Therefore, weather is not expected to adversely impact airline
operations performed under 180-minute ETOPS authority.
The above weather study used conservative assumptions. It did not take
advantage of likely improvements such as routing flexibility, and several
airports were excluded from it because not enough was then known about
them. All these factors together provide additional conservatism to offset
situations not addressed by the study (e.g., excessive crosswinds).
Boeing can help
airlines initiate
polar services
February 15, 2008
Boeing has helped many airlines initiate polar operations. We will continue
to assist operators by providing information and guidance about regulatory
requirements, cold fuel management, alternate airports, communications,
navigation, compliance demonstration, and other aspects of polar flying.
See Section 14 for a brief overview of the services and support that Boeing
and engine manufacturers provide to Boeing ETOPS operators in general.
ETOPS Explained
7–7
7. Polar Flying and ETOPS (continued)
Conclusions
February 15, 2008
This section of ETOPS Explained has shown that
„ The industry has a half-century of experience in far-northerly flight
operations on routes that extend north of the Arctic Circle.
„ Since 2001, many thousands of routine airline flights have been made
using the polar route tracks across the North Polar region itself.
„ Polar flying reduces travel times, fuel burn, and emissions in flight
operations between many existing Asia–North America city pairs,
and makes possible new nonstop services.
„ Sufficient alternate airports are available to support polar ETOPS.
„ Boeing 747s and 777s (the latter flying under current ETOPS rules)
today account for nearly all polar flying.
„ Enacted on February 15, 2007, the U.S. ETOPS rule of 2007
„ Provides for ETOPS beyond 180 minutes, and makes the design
capabilities of the airplane type (airplane-engine combination)
the basis for establishing that type’s maximum diversion authority.
„ Also applies ETOPS regulations to the operation of three- and fourengine passenger airplanes on extended-diversion-time routes.
„ Formalizes North and South Polar operational requirements and
makes these requirements applicable at all times to all airplanes
within these regions.
„ Because of their different ETOPS thresholds, twinjets require ETOPS
to fly the North Polar routes whereas tris and quads generally do not.
„ As polar operations evolve, long-range, smaller capacity twinjets like
the 777 and 787 Dreamliner will let airlines inaugurate new services
that directly link additional city pairs in Asia and North America.
„ Boeing assists operators with their preparations for and validation
of polar flight operations.
ETOPS Explained
7–8
The Advantage of Polar Operations
Figure 7-1
Section 8
Airliner Diversions
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained examines
„ ETOPS requirements regarding the availability of en route alternate
airports suitable for airplane diversions.
„ ETOPS experience regarding diversions and air turnbacks, including
„ The reasons why jetliners divert.
„ Single-engine cruise during an extended diversion by a twoengine jetliner or twinjet.
„ The U.S. ETOPS rule of 2007 and its effect on diversion requirements during extended operations—this new rule applies ETOPS
more broadly to also embrace tri and quad passenger jetliners, not
just twinjets as in the past (see Section 2).
„ The current availability of en route alternate airports to support
ETOPS flying worldwide.
„ Specific diversion requirements in the event that an engine fails
or is shout down in flight.
„ The reliability of engines and other ETOPS significant systems.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
In commercial flight operations, situations can sometimes arise that require
a flight to divert to an airport other than its intended destination. Airliner
diversions to unscheduled landings at en route alternate airports are very
rare events. Of course, diversions are not exclusively an ETOPS issue, nor
are they exclusively a twinjet issue. In the interest of safety, any flight may
someday need to divert to an alternate airport.
Diversion is a planned capability that enhances safety by providing flight
crews with opportunities for earlier or safer landings. Modern commercial
jet transports and their high-bypass-ratio fanjet engines are so enormously
reliable that more than 90 percent of diversions occurring on ETOPS flights
are the result of non-airplane-related factors like passenger illness, adverse
winds, turbulence, or weather conditions at the intended destination. Fewer
than 10 percent of ETOPS diversions are related to the functioning of the
airplane or its systems.
(continued)
February 15, 2008
BCA ETOPS White Paper
8–1
8. Airliner Diversions (continued)
Overview
(cont’d)
Two-engine jetliners occasionally divert, just as do jets with three or four
engines. These twinjet diversions may divided into 3 categories:
„ Diversions made by twinjets that are not ETOPS capable.
„ Diversions made by ETOPS-capable twinjets that divert during
a non-ETOPS portion of a flight.
„ Diversions made by ETOPS twinjets that divert from the ETOPS
portion of flight.
This last category of twinjet diversion is particularly rare. Regardless of
when the diversion occurs, if it was triggered by an in flight engine shutdown (IFSD), the twinjet proceeds on its remaining engine until an airport
is reached. This single-engine cruise is a planned, designed, and certified
capability of twinjets (see Section 3 for more information).
As for ETOPS, it is the conservative and evolutionary regulatory framework
under which airlines have long flown twinjets in extended operations, which
are flight operations on routes that at some point take the airplane far from
an airport. Flown since 1985, ETOPS ranks among the very safest and most
reliable of all flight operations. It is the state-of-the-art in long-distance air
travel (see the Introduction and Section 1 of ETOPS Explained).
On February 15, 2007, the U.S. Federal Aviation Administration (FAA)
enacted a comprehensive regulatory updating of ETOPS. Called the U.S.
ETOPS rule of 2007, this rulemaking applies ETOPS requirements more
broadly to also embrace the extended operation of three- and four engine
passenger jets, not just twinjets. It also provides for ETOPS beyond 180
minutes, setting the stage for compliant operators to fly approved twinjets
and other airplanes on optimal routings between virtually any two cities
on earth for which they have sufficient range. See Section 2 for a detailed
look at this 2007 rule, which is addressed briefly in this section only in the
specific context of airliner diversions.
About
airliner
diversions
February 15, 2008
When discussing airliner diversions, it should be noted that:
„ Diversion to an alternate airport is a planned capability that enhances
safety for all airliners by providing opportunities for earlier/safer
landings.
„ Most diversions result from weather, passenger illness, or other
factors unrelated to how many engines a jetliner has.
„ Fewer than 10 percent of airliner diversions during ETOPS flights
are related to the functioning of the airplane or its systems.
„ Fewer than 5 percent of diversions during ETOPS flights are the
result of an IFSD (fig. 8-1).
„ On average, fewer than 1 in 100,000 ETOPS flights diverts from
the ETOPS portion of flight as a result of an IFSD.
BCA ETOPS White Paper
8–2
8. Airliner Diversions (continued)
Why jetliners
divert
Jetliners divert for reasons that can include passenger illness, adverse winds
aloft, bad weather at the intended destination, turbulence, fuel leaks, loss of
cabin pressure, cargo fires, smoke in the flight deck or cabin, propulsion or
other significant system failures, and so on. As stated, the vast majority of
diversions are unrelated to the functioning of the airplane and its systems.
About ETOPS
and diversions
ETOPS is the global regulatory framework under which the airline industry
has long operated twinjets on air routes that at some point take the airplane
beyond one hour’s flight time, at single-engine cruise speed, of an alternate
en route airport. ETOPS uses a dual preclude and protect philosophy that
enhances safety and reliability in two ways:
„ ETOPS-related design improvements (see Section 9) and maintenance
practices (see Section 12) increase the reliability and robustness of
jetliner engines and systems, making it less likely that the flight will
need to divert to an en route alternate airport.
„ ETOPS operational requirements introduce proactive measures that
further protect the jet, its passengers, and its crew should a diversion
become necessary or desirable (see Section 2).
ETOPS relies
on alternate
airports
The conservative, evolutionary ETOPS program relies on the availability of
alternate airports to enhance operational safety during extended operations.
Since ETOPS flying began in 1985, for example, ETOPS twinjet operators
have been required to
„ Designate suitable alternate airports for the ETOPS routes they fly.
„ Verify before dispatch or flight release that sufficient alternate airports
are at or above specified weather minimums to support the flight.
„ Again check weather at the beginning of the ETOPS portion of flight
to ensure that these designated alternates continue to be available.
About
207-minute
ETOPS
In 2000, the FAA approved 207-minute ETOPS (see Section 1) for use on
a flight-by-flight exception basis by 777 operators on existing 180-minute
North Pacific ETOPS routes. This 207-minute authority is used when an
alternate airport necessary for 180-minute ETOPS is unavailable, usually
because it does not meet ETOPS weather minimums at dispatch. Other
counties that grant 207-minute ETOPS diversion authority include Japan,
Korea, Taiwan, Singapore, and the United Arab Emirates (see Section 1 of
ETOPS Explained for more information about 207-minute ETOPS).
Note that 207-minute ETOPS arose as a 15-percent operational extension to
the existing 180-minute “twinjet ETOPS” diversion authority. Therefore, it
is not subject to the additional requirements for beyond-180-minute ETOPS
introduced by the U.S. ETOPS rule of 2007 (see below and Section 2).
February 15, 2008
BCA ETOPS White Paper
8–3
8. Airliner Diversions (continued)
The U.S. ETOPS
rule of 2007
On February 15, 2007, the U.S. FAA enacted a comprehensive new ETOPS
rulemaking that
„ Codifies ETOPS for the first time directly in the U.S. federal aviation
regulations, as befits such large-scale global flight operations.
„ Updates the requirements applicable to twinjet extended operations.
„ Applies selected ETOPS requirements to the extended-diversiontime operation of three- and four-engine passenger jetliners.
„ Provides for ETOPS beyond 180 minutes, and specifies additional
more-stringent requirements for these new operations.
„ Establishes the design capabilities of each airplane type (i.e., airframe /
engine combination) as the basis for determining that airplane type’s
maximum allowable diversion authority.
„ Defines allowable diversion authorizations and requirements for the
different regions of the world based on the overall operational needs
of each region.
See Section 2 of ETOPS Explained for a full description the 2007 ETOPS
rule, which is addressed below just in the context of airliner diversions.
About ETOPS
flight planning
ETOPS flight planning requires operators to formally identify the alternate
airports on which their extended-diversion-time flight operations rely. As
the FAA observes in Advisory Circular 120-42A, “These suitable en route
alternates serve a different purpose than the destination alternate airport,
and would normally be used only in the event of an engine failure or loss
of primary airplane systems.” Issued in 1988, AC 120-42A also specifies
required minimum weather conditions at designated alternate airports that
must be met before ETOPS flights may dispatch.
Under the ETOPS rule of 2007, additional planning requirements apply to
operators of twinjets and three- and four-engine passenger jets when they
fly routes that take their airplanes beyond 180 minutes of an airport. FAA
AC 120-42B—the 2008 AC that addresses this rule’s operational aspects—
provides further guidance in this regard.
Alternate
airports allow
global ETOPS
The North Atlantic, North Pacific, and North Polar areas of operation all
have ample alternate airports to support ETOPS flying. See Sections 5,
6, and 7 for specific information about these ETOPS areas of operation.
Under the 2007 ETOPS rule, compliant operators of approved long-range
jetliners gain newfound flexibility to fly optimal routings between virtually
any two cities on earth for which their two- , three- , or four-engine jetliners
have sufficient range (see Section 2).
February 15, 2008
BCA ETOPS White Paper
8–4
8. Airliner Diversions (continued)
Duration of
real-world
diversions
The vast majority of airplane diversions are significantly shorter than the
planned maximum diversion time for the extended-diversion-time route
being flown. In fact, although millions of 180-minute ETOPS flights have
been made since 1988, there has been just one ETOPS diversion of about
180 minutes duration.
Few diversions
are caused by
engine failure
The fanjet engines that power today’s world commercial jetliner fleet are
enormously reliable. The probability that a high-bypass-ratio fanjet will
fail or need to be shut down in flight is normally less than 1x10-5 per flight
hour. This translates to less than one engine in-flight shutdown (IFSD) per
100,000 engine flight hours. As a result, airline pilots who are just starting
out today have a high expectation of never experiencing an IFSD during
their entire careers aloft.
Engine IFSDs tend to occur on takeoff or during initial climb when thrust
settings are at their highest. They may also occur on descent when engine
thrust is reduced following a long period of continuous operation at one
power setting. In contrast, IFSDs rarely occur during the cruise phase of
flight. In fact, the probability of an IFSD in cruise is less than one-tenth
that of one during the flight’s other phases. Of course, it is only during
cruise that ETOPS is performed and a long diversion is possible.
Not all engine
problems result
in a shutdown
or diversion
Not all propulsion-related problems necessarily cause an engine to fail or
be shut down in flight, thus triggering a diversion. Examples of problems
that typically do not require shutdown or diversion include
„ High vibration levels.
„ Low oil quantity indication.
„ Exhaust gas temperature (EGT) spikes.
„ Electronic engine control (EEC) issues.
About
propulsion
reliability
During the propeller era a half-century ago or more, concerns about flight
safety focused first and foremost on the airliner’s engines. Because the
reliability of piston aero engines was limited, long-range propeller airliners
were required by regulation to have four engines (see Section 1).
In contrast, today’s modern high-bypass-ratio fanjet engines are at least
100 times more reliable than the large piston aero engines of the propeller
era. As a result, the industry no longer views propulsion as the dominant
concern during extended-diversion-time operations. Instead, propulsion
is seen as just one of many areas that collectively contribute to the overall
safety of a flight. See Sections 1, 2, and 3 of ETOPS Explained for more
information about propulsion safety, past and present.
February 15, 2008
BCA ETOPS White Paper
8–5
8. Airliner Diversions (continued)
Requirements
in the event of
engine failure
If an engine fails or is shut down in flight, FAA regulations require the pilot
in command (PIC) of a twin-engine jetliner to land at the nearest suitable
airport, in terms of flight time, at which a safe landing can be made. If the
airport of origin is nearest, an air turnback is performed. If the destination
airport is nearest, the airplane continues on to land as planned. In all other
instances, a diversion must be performed to an en route alternate airport.
Current FAA requirements recognize that the nearest suitable airport may
not always be the nearest adequate airport in terms of flight time. FAA
regulations further recognize that, under certain failure conditions, it may
be preferable from a safety standpoint for the twinjet to land at an airport
not designated as an ETOPS alternate airport in its ETOPS flight plan (see
Section 2 for more information about IFSD diversion requirements).
The following two examples are provided to illustrate possible scenarios
that might confront the PICs of ETOPS airplanes that experience IFSDs.
Example 1:
ETOPS twinjet
A twinjet operating under 240-minute ETOPS authority, as provided for by
the ETOPS rule of 2007, suffers an in-flight engine failure. The flight crew
determines that, at single-engine cruise speed, they are 220 minutes from
the flight’s destination and 210 minutes from the nearest suitable alternate
airport. In this hypothetical example, it makes no difference whether this
nearest alternate airport is one of the flight’s designated ETOPS alternates.
The PIC must now decide whether to divert to this suitable alternate airport,
as required by U.S. federal aviation regulation 14 CFR 121.565 (a), or press
on to the flight’s intended destination. If the PIC deems this alternate to be
unsuitable, the regulations allow the flight to continue on although the PIC
will have to explain why he or she thought the airport not suitable. But even
if the PIC deems this alternate suitable, the flight may still legally continue
on to the destination if the PIC believes that so doing will be safer. As the
airplane commander, the PIC has ultimate legal authority to take whatever
course of action he or she believes is safest for all aboard.
In this instance, a number of factors might lead the PIC to conclude that it
is safer to continue to the destination airport, including:
„ The flight crew is familiar with the destination airport but not
with the alternate airport.
„ The destination airport may have a longer or wider runway.
„ The destination airport may have superior rescue and firefighting
services, which could be pertinent depending on the situation.
„ If a landing is made at the alternate airport, everyone aboard will
have to take at least one more flight with associated risks, including
those relating to an unfamiliar alternate airport.
(continued)
February 15, 2008
BCA ETOPS White Paper
8–6
8. Airliner Diversions (continued)
Example 1:
ETOPS twinjet
(cont’d)
In accordance with 14 CFR 121.565(d), if the PIC of a twinjet that has an
IFSD decides to land at any airport other than the nearest suitable airport,
the PIC must file a report explaining the reasons why. In this instance, the
PIC might observe that 10 additional minutes of single-engine cruise time
exposed the flight to virtually no additional risk, and also that landing at the
destination airport reduced total risk exposure by presenting more favorable
circumstances at landing and avoiding an additional flight. In performing
evaluations of this nature, in fact, PICs might justifiably conclude that the
benefits of continuing on outweigh more than a 10-minute difference.
Example 2:
ETOPS quad
A four-engine passenger jetliner is performing an ETOPS flight. Early in
the ETOPS portion of this intercontinental flight, one engine begins to run
erratically and the flight crew shuts it down.
Regulations require this flight to land at the nearest suitable airport unless
the PIC determines that flying to some other airport, such as the flight’s
scheduled destination, is just as safe. In addition to factors cited in the
previous example, the PIC must consider factors such as altitude, airplane
weight, and usable fuel supply.
Flying at the lower three-engine cruise altitude decreases airplane range so
the PIC must take into account the increased risk of running out of fuel. If
fuel is determined not to be a constraint to continuing on, then diverting to
an alternate airport and landing there may not be the most desirable course
of action because it would expose the airplane, its crew, and its passengers
to greater total risk.
In twinjets,
single-engine
cruise is a
planned
capability
Single-engine cruise is a planned, designed, and certified capability of all
twinjets. Therefore, although diversion following IFSD is an emergency, it
is not an unsafe condition. Regardless of whether or not the flight is being
conducted under ETOPS rules, when an IFSD occurs, the flight crew of a
twinjet must
„ Attend to the flight procedures relating to engine failure.
„ Initiate a descent to one-engine-inoperative cruise altitude.
„ Communicate with the appropriate en route authority.
„ Navigate to the nearest suitable airport.
The above actions are nearly identical to those required of three- or fourengine jetliner flight crews following IFSD. The difference is that, under
FAA regulations, diversion in this situation is elective for tris and quads
although caution and common sense are expected (some operators require
a precautionary diversion as a matter of internal airline policy). Of course,
all flight crews routinely practice for IFSDs and one-engine-inoperative
approaches and landings during their simulator training sessions.
February 15, 2008
BCA ETOPS White Paper
8–7
8. Airliner Diversions (continued)
ETOPS
engine-related
diversion
experience
Vast industry experience with ETOPS confirms that two engines provide a
safe level of propulsion redundancy. For example:
„ Out of the 387,000 ETOPS flights logged by 777s and 767s in the
12 months ending June 2007, there was just 1 propulsion-related
diversion following IFSD during the ETOPS portion of flight.
„ No twinjet has ever suffered an IFSD and then been unable to land
safely because of a second IFSD due to unrelated causes (e.g., related
causes include fuel mismanagement, volcanic ash)—the unrelated failure
of both engines on a flight hasn’t happened in 343 million twinjet flights
(through July 2007) and is unlikely to occur in the next billion flights
(see Sections 1, 3, and 4).
ETOPS
electrical
system–related
diversion
experience
Out of the 387,000 777 and 767 ETOPS flights logged in the 12 months
ending June 2007, there were no diversions whatsoever from the ETOPS
portion of flight due to electrical-system causes. This extreme electricalsystem reliability reflects the Boeing design emphasis on:
„ Redundancy—hydraulic motor generators (HMG) and auxiliary
power units (APU) are examples of electrical system redundancy
that ensures the availability of backup electrical power.
„ Robustness—in recent decades, total electrical outputs have been
increased, component redundancy has been further improved, and
the challenge of starting cold-soaked APUs at cruise altitudes has
largely been resolved.
„ Automatic load shedding—should a failure or combination of
failures result in reduced electrical generation in flight, all Boeing
jets have automatic load shedding that cuts power to non-essential
systems while preserving power to critical ones, thereby minimizing
degradation in communication, navigation, and other vital systems.
Conclusions
This section of ETOPS Explained has shown that:
„ Airliner diversion is a planned capability that enhances safety by
providing flight crews with options for earlier/safer landings.
„ Diversions are not just a twinjet or an ETOPS issue.
„ Any jetliner may someday have to divert.
„ Most jetliner diversions result from weather, passenger illness,
or other factors unrelated to the functioning of the jetliner’s
systems or how many engines it has.
„ The availability of alternate en route airports enhances safety
for all flight operations.
„ Single-engine flight during a twinjet diversion following IFSD is
a planned, designed, and certified capability of twinjets.
(continued)
February 15, 2008
BCA ETOPS White Paper
8–8
8. Airliner Diversions (continued)
Conclusions
(cont’d)
„
„
„
„
„
February 15, 2008
The ETOPS program addresses airliner diversions through
„ Alternate-airport planning requirements.
„ A preclude and protect philosophy that
„ Reduces the rate at which airliners divert.
„ Protects those diversions that do occur.
The U.S. ETOPS rule of 2007
„ Embraces the extended-diversion-time operation of three- and
four-engine passenger jetliners, not just twinjets as in the past.
„ Provides for beyond-180-minute ETOPS and requires
„ Additional diversion planning relative to ETOPS at or
below 180 minutes (including 207-minute ETOPS).
„ Passenger recovery plans for every alternate airport on
which the operator’s beyond-180-minute ETOPS relies.
Propulsion-related diversion requirements remain unchanged under
the 2007 ETOPS rule.
Under FAA regulations, all airplanes must divert to a suitable
airport in the event of an IFSD, although this requirement differs
depending on number of engines:
„ Twinjets must divert to the nearest suitable airport, which is not
necessarily the nearest adequate airport.
„ Three- and four-engine jets may to continue to an airport beyond
the nearest suitable one if the crew determines that so doing will
not diminish overall flight safety (however, flight crews often
elect to divert to the nearest suitable airport on a precautionary
basis or according to internal airline policy).
ETOPS twinjet experience confirms
„ The suitability of long-range twinjets to extended operations.
„ The enormous reliability of these twinjets’ engines and systems.
BCA ETOPS White Paper
8–9
777 ETOPS Relevant Events - Diversions and IFSDs
12 Months - July 2006 through June 2007
A summary of the 86 reported diversions out of 174,400 777 ETOPS flights.
Only one of the five diversions in the ETOPS portion of flight was due to engine IFSD.
56 of the 86 reported diversions had non-technical causes such as weather or medical.
Most non-technical diversions are not reported.
ETOPS portion
Prior to
ETOPS portion:
1 IFSD /
26 Diversions
Departure
(174,400 Flights)
1 IFSD /
5 Diversions
Alternate
Airport
After ETOPS
portion:
1 IFSD /
55 Diversions
Alternate
Airport
Destination
ETOPS Events Usually Occur Outside the ETOPS Portion of Flight
777DivIFSD.cvs
Figure 8-1
Section 9
Boeing ETOPS Twinjet Experience
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Summarizes the capabilities and characteristics that distinguish
ETOPS twinjets from non-ETOPS twinjets.
„ Provides brief overviews, presented in chronological order, of the
service histories of these Boeing ETOPS twinjets:
„ Boeing 737 (all three generations).
„ Boeing 767.
„ Boeing 757.
„ Boeing 777.
„ Addresses the Boeing 787 Dreamliner (2009 service entry).
„ Summarizes the changes to twinjet ETOPS requirements brought
about by passage of the U.S. ETOPS rule of 2007.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
ETOPS is the global regulatory framework under which airlines around the
world have long operated two-engine jetliners, or twinjets, on routes that at
some point take the airplane beyond one hour’s flight time (at single-engine
cruise speed) of an airport. When approved twinjets fly these extendeddiversion-time routes under ETOPS rules, they are said to be performing
twinjet extended operations or twinjet ETOPS.
Using twinjets on extended-diversion-time routes began on a limited basis
in the South Pacific in the mid-1970s. Described later in this section, those
successful first-generation 737 operations helped set the stage for ETOPS,
which began the following decade. See the Introduction and Section 1 of
ETOPS Explained for an overview of ETOPS and its evolution, and Section
6 for more about the pioneering pre-ETOPS 737 trials in the South Pacific.
Flown since 1985, ETOPS is hugely successful. Over 5.8 million ETOPS
twinjet flights were logged by June 2007, and some 143 ETOPS operators
worldwide fly over 1,800 more each day. Boeing twinjets alone account
for over three-quarters of this total, having logged over 4.6 million ETOPS
flights. In 2007, there are 109 Boeing ETOPS twinjet operators who make
about 1,450 more ETOPS flights every single day (fig. 9-1).
February 15, 2008
ETOPS Explained
9–1
9. Boeing ETOPS Twinjet Experience (continued)
Overview
(cont’d)
This vast industry experience shows that
„ ETOPS ranks among the very safest and most reliable of all flight
operations; it is the state-of-the-art in long-range air travel.
„ Twinjets are well suited to long-haul operations on extendeddiversion-time routes, and are likewise the state-of-the-art.
„ As a category, twinjets are the safest, most reliable, most
efficient, and most environmentally preferred jetliners.
„ In 2006, 92 percent of all jetliner flights were twinjets (fig. 9-2).
„ In 2006, more than 95 percent of all new jetliners delivered
by Airbus and Boeing were twinjets.
See the Introduction and Section 1 for more information about ETOPS,
and Section 3 for more information about twinjets and their safety.
ETOPS safety
and reliability
enhancements
The ETOPS program enhances safety and reliability in three ways:
1. ETOPS airplane design improvements.
2. ETOPS maintenance requirements.
3. ETOPS operational requirements.
The first of these three ETOPS-program components is what defines an
ETOPS twinjet and distinguishes it from a non-ETOPS-capable twinjet.
In the early 1980s, the airplane and engine manufacturers worked with the
airlines and regulatory authorities to help pioneer ETOPS. The role of the
manufacturers was to define and produce enhancements to the propulsion,
electrical, and other key systems of the twinjets proposed for extendedrange operation. These configurational enhancements included improved
avionics cooling, upgraded auxiliary power unit (APU) reliability and inflight starting, increased cargo fire suppression, and greater redundancy of
flight-critical systems to enhance safety and reliability on ETOPS flights.
ETOPS
has lifted
the industry
In the 1980s when ETOPS was new, there was a large difference between
an ETOPS twinjet and a non-ETOPS airplane. Today, the difference is far
smaller because the world’s airframe and engine manufacturers have been
bringing all their products up to the higher ETOPS standard.
In addition to its direct benefits, therefore, ETOPS has indirectly lifted the
entire industry to a higher level of safety and reliability. All commercial
flying, twinjet and otherwise, benefits from gains made in the reliability
and robustness of fanjet engines and airplane systems that were achieved
through the ETOPS program and subsequently implemented more broadly
by the world’s airframe and engine manufacturers.
February 15, 2008
ETOPS Explained
9–2
9. Boeing ETOPS Twinjet Experience (continued)
About
twinjet safety
It is important to note that
„ Boeing and all other commercial jet transports are already safe, as
ensured by the rigorous type certification process.
„ Twinjets are the safest jetliners, and have been so since they were first
introduced many years before ETOPS came into being (fig. 9-3).
„ The intrinsic safety and reliability of modern twinjets does not
diminish as range increases.
„ ETOPS airplane design enhancements serve to further enhance this
existing twinjet safety and reliability, not to “make a twinjet safe for
an extended-duration diversion.”
See Section 3 for more information about twinjets and their safety.
About Boeing
ETOPS jetliners
A Boeing 767 twinjet made the first ETOPS flight in 1985. By the end of
June 2007, 5.8 million ETOPS flights had been logged and Boeing twinjets
accounted for more than three-quarters of them. All Boeing twinjet models,
past and present, are ETOPS capable as confirmed by the below survey.
Boeing 737
There have been three generations of Boeing 737 airliner:
„ First generation—the 737-100 and 737-200 entered service in 1968.
„ Middle generation—the 737-300 debuted in 1984, followed by the
737-400 in 1988 and the 737-500 in 1990.
„ Next-Generation 737—today’s 737 family includes the 737-600, -700,
and -800, all of which entered service in 1998, and the -900, which
entered service in 2001. This family includes extended-range (ER)
737 models and the 737-based Boeing BBJ series of business jets.
The Next-Generation 737 family is the second major derivative of the 737,
the world’s most reliable and popular jetliner. All three 737 generations
have played significant roles in ETOPS, as described below.
Pioneering
operations
In the mid-1970s, Boeing 737 twinjets flying in the South Pacific region
became the first turbine-powered transports to exceed the 60-minute rule,
a 1953 regulation that limited twin-engine airliners to routes that remained
at all times within one hour’s flying time, at single-engine cruise speed, of
an airport (see Sections 1 and 3 for more information about this operating
restriction on two-engine airplanes).
The Pratt & Whitney JT8D engines of those first-generation 737s were far
more reliable than the piston aero engines in use when the 60-minute rule
was enacted. This greater reliability set the stage for operators to safely fly
737s beyond 60 minutes of an airport on these “South Seas” routes.
February 15, 2008
ETOPS Explained
9–3
9. Boeing ETOPS Twinjet Experience (continued)
Pioneering
operations
(cont’d)
Thanks to those pioneering South Pacific operations, when ETOPS began
in 1985, the industry already had a decade of successful and very promising
overwater extended operations experience under its belt (see Sections 1 and
6 for more information). The first-generation 737 twinjet family went on to
be certified for 120-minute ETOPS in December 1985.
Middle 737
generation
The 737-300 received 120-minute ETOPS type design approval from the
U.S. Federal Aviation Administration (FAA) in November 1986, nearly
two years after it entered service. In 1990, the 737-400 and -500 were also
approved for 120-minute ETOPS.
Next-Generation
737 family
The 737-600, -700, and -800 were approved for 120-minute ETOPS by the
FAA in December 1998 and the European Joint Aviation Authorities (JAA)
in November 1999. The 737-900—last and largest member of the NextGeneration 737 family—was granted FAA and JAA 180-minute ETOPS
approval in April 2001 and entered service that year. The performance
of the 737-900 was initially constrained, limiting its operator appeal until
the 737-900ER extended-range version became available. The 737-900ER
was granted 180-minute FAA ETOPS approval in April 2007.
The Next-Generation 737 family offers capabilities never before seen in its
size class, including 180-minute ETOPS. Airlines use the Next-Generation
737 family’s unique combination of long range, smaller capacities, superb
economics, and 180-minute ETOPS to link a growing number of airports
in all parts of the world. One good example is between the U.S. mainland
and Hawaii (see Section 6) (fig. 9-4). Boeing sells Next-Generation 737s
configured either non-ETOPS or ETOPS. ETOPS conversion after the fact
of non-ETOPS examples is easy and inexpensive.
The Boeing BBJ is a very capable and very comfortable family of business
jets based on the Next-Generation 737 twinjet family. In June 2002, BBJs
began setting records in scheduled services across the North Atlantic as
pioneering operators exploited their capabilities. Configured with just 48
business-class seats and flying up to 10 hours at a time, these all-business
services often connect busy hubs with secondary airports. Premium BBJ
alternative services like these are continuing to expand.
737 ETOPS
summary
February 15, 2008
As of June 2007, 34 Boeing 737 ETOPS operators worldwide perform 177
737 ETOPS flights a day. The center of 737 ETOPS activity is the Pacific,
where 737s have logged over 400,000 ETOPS flights since 1985, or about
one-quarter of all Boeing ETOPS twinjet flights in the region. They make
more than 100 more ETOPS flights every day. The 737 is the most reliable
jetliner in history with dispatch reliability consistently above 99 percent.
ETOPS Explained
9–4
9. Boeing ETOPS Twinjet Experience (continued)
Boeing 767
Although not originally designed with extended operations in mind, the
Boeing 767 has been an ETOPS workhorse. A TWA 767 made the first
ETOPS flight in 1985, and at one point 767s accounted for fully 80 percent
of all ETOPS flights! Today this figure is about 50 percent owing to the
success of the Boeing 777 (see below), the first all-new airplane designed
from the outset for ETOPS flying.
The twin-aisle 767 twinjet entered airline service at the end of 1982 with
remarkable fuel efficiency for its day. When ETOPS became available in
1985 with 120-minute diversion authority, U.S. airlines quickly realized
they could fly their own European services from many airports instead of
continuing to feed their traffic to New York for international carriers to
then transport to Europe.
The 767’s excellent per-seat operating economics allowed it to compete
successfully against the 747, which has twice as many seats. It let airlines
link smaller population centers on both sides of the Atlantic with direct air
services that would not have been profitable with a 747-size airplane. The
result of all this “bypass flying,” which has linked a growing number of
airports on both sides of the ocean, has been a profound transformation of
air service patterns known as market fragmentation (see Section 5). Of
course, U.S. deregulation and European regulatory liberalization have also
played a role but they are beyond the scope of this brief overview.
The 767 also flies in the Pacific region. Although it does not quite have the
range or capacity for widespread use across the North Pacific, it is widely
used on shorter routes within Asia-Pacific. All Nippon Airways (ANA) is
the largest non-U.S. 767 operator.
767 ETOPS
summary
Since 1985, the 767 twinjet family has performed more ETOPS flights than
all other airplane types combined (the 777 has made most of the remainder,
as described below). More than 2.8 million 767 ETOPS flights have been
logged as of June 2007 (fig. 9-5).
Airlines have flown 767 ETOPS over every one of the world’s oceans and
continents except Antarctica. The safety and schedule reliability of the 767
in ETOPS service are legendary. On average, less than one out of every
3,500 767 ETOPS flights has to divert as the result of a technical problem
with the airplane. Out of the last 213,000 767 ETOPS flights (12 months
through June 2007), there have been only two technical diversions from the
ETOPS portion of flight, neither of which was propulsion-related.
Of the 99 operators that have been approved for and flown 767 ETOPS,
some 63 were still flying the 767 as of June 2007.
February 15, 2008
ETOPS Explained
9–5
9. Boeing ETOPS Twinjet Experience (continued)
Boeing 757
The Boeing 757 entered service in January 1983 and received its ETOPS
approval in December 1986. Although production ended in October 2004,
more than a thousand 757s were built and they will remain in service for
decades to come. There are three 757 models: the 757-200, the 757-200F
Freighter, and the 757-300, a stretched model that entered service in 1999.
The 757 combines high performance with exceptional range capability. In
many ways, it’s a single-aisle jet that performs like a widebody. As a result,
757s often fly ETOPS in the colors of many smaller nations, such as Iceland
or Ethiopia.
This twinjet performs ETOPS in all regions of the world. Some 757s even
fly across the North Atlantic in scheduled ETOPS services that can bring
direct transatlantic air links to smaller population centers with insufficient
travel demand for twin-aisle airplanes. Freighter versions of the 757 also
fly ETOPS, of course.
A large portion of 757 ETOPS is performed by European charter services
when they take “inclusive tour” vacationers to Caribbean and Indian Ocean
destinations. Charter operators have logged more ETOPS flights with the
757 than with any other airplane type.
757 ETOPS
summary
As of June 2007, 757 twinjets have performed more than 318,000 ETOPS
flights covering every continent and ocean except the Antarctic. About 160
additional 757 ETOPS flights are logged every day (fig. 9-6).
In all, 57 operators worldwide have been approved to fly 757 ETOPS. As
of June 2007, 32 of these operators are still flying 757s although some are
not currently flying them on ETOPS routes. 757 schedule reliability
typically stays around 99 percent.
Boeing 777
The Boeing 777—the largest twin-engine aircraft ever built—was designed
from the outset for ETOPS. In fact, its very first revenue flight on June 7,
1995, was an ETOPS flight between London and Washington, DC.
No other jetliner family currently in service or under development offers
as much range as the 777 family, which has five models and two fuselage
lengths (the 777-200 and the longer 777-300). The 777-300ER, which
entered service in May 2004, can fly 365 passengers (as many as an earlymodel 747) a distance of 7,930 nautical miles, which is further than today’s
long-range 747-400 and about the same as the new 747-8 Intercontinental.
The 777-200LR entered service in 2006 as the longest range airliner in the
history of commercial aviation. With a full payload of 301 passengers, it
can fly 9,450 nautical miles nonstop.
February 15, 2008
ETOPS Explained
9–6
9. Boeing ETOPS Twinjet Experience (continued)
Boeing 777
(cont’d)
The 777 is also the most reliable twin-aisle jetliner in history. The world
777 fleet, which as of June 2007 numbered 641 airplanes, consistently
demonstrates schedule reliability above 99 percent (fig. 9-7).
The capacity, performance, and reliability of the 777 twinjet family makes
it well suited to operations on North Pacific and Polar routes, which these
workhorse twinjets fly under ETOPS rules (see Sections 6 and 7). The 777
is also extremely popular in transatlantic service. In 2007, 777s accounted
for one out of every six flights made across the North Atlantic (fig. 9-8).
About Early
ETOPS
A stated goal of the 777 program was service readiness and reliability—
including 180-minute ETOPS capability—so initial operators could realize
the 777’s potential on the extended routes for which it was designed.
At that time, FAA Advisory Circular (AC) 120-42 required operators to fly
a proposed ETOPS twinjet for at least 12 consecutive months before they
could be granted an ETOPS operational approval (see Section 1). It was
through that conservative approach that ETOPS let the industry inaugurate
two-engine extended operations and build service experience with twinjets
not originally designed to specific ETOPS requirements.
The 777 program presented the opportunity for a different approach, that
being to design the all-new twinjet from the outset for ETOPS. From the
start of the program, therefore, Boeing worked with the industry and the
regulatory authorities to achieve the goal of 777 ETOPS certification prior
to first delivery. To this end, the FAA issued the Early ETOPS Special
Condition, which provided the means for achieving this common goal.
777 ETOPS
validation
Boeing worked with the engine manufacturers, regulatory authorities, and
airlines to define a conservative means to validate the 777 design for Early
ETOPS approval. This ETOPS validation included
„ Design processes that drew from “lessons learned” with the 767
and other jetliners.
„ APU endurance cycle testing.
„ A 3,000-cycle ETOPS engine endurance test series for each
of the three available engine types.
„ A 1,000-cycle ETOPS flight test series for each of the three
available engine types.
Early ETOPS and its validation were very successful. See Section 1 for
more information about Early ETOPS, and Section 2 for how the 777
program experience provides a template for “out-of-the-box” ETOPS typedesign approvals for future new airplanes.
February 15, 2008
ETOPS Explained
9–7
9. Boeing ETOPS Twinjet Experience (continued)
777 ETOPS
summary
As of June 2007, the world’s airlines had accepted delivery of 641 777s, all
of which are ETOPS capable. This world 777 fleet has been logging more
than 15,000 ETOPS flights per month, a figure that is rising steadily. More
than 60 percent of all 777 flight-hours are logged on ETOPS routes, so the
majority of 777s in the air at any given time are flying ETOPS. In short, the
777—like the 767—is an ETOPS workhorse.
Of the 40 777 operators in June 2007, 33 fly ETOPS. Most are approved for
180-minute ETOPS, and most obtained their ETOPS operational approvals
through the Accelerated ETOPS process. Out of the 12 777 operators who
were flying the North Pacific in June 2007, 11 are approved for 207-minute
ETOPS (see Section 1 for more information about Accelerated ETOPS and
207-minute ETOPS).
Boeing 717
The Boeing 717 is a 100-passenger twinjet that entered service in October
1999. Although primarily dedicated to short-haul use, it offers airlines the
capability to also fly longer ranges.
The 717 received FAA type-design approval for 75-minute ETOPS in May
2004, with possible later expansion to 120-minute ETOPS. No operators
yet fly 717 ETOPS, but the capability is there should they need it.
Boeing 787
Dreamliner
The super-efficient Boeing 787 Dreamliner is an all-new airliner scheduled
to enter service in 2009. It will replace the 767 and 757, bringing large-jet
range capabilities to mid-size airplanes.
Members of the 787 Dreamliner twinjet family will use 20 percent less fuel
for comparable missions than any similarly sized airplane, which will also
gives them unrivaled environmental performance. A cruise speed of Mach
0.85 makes the 787 as fast as today’s fastest widebodies.
The 787 Dreamliner family has three members. The 787-8 is sized to carry
210–250 passengers on routes of 7,650 to 8,200 nautical miles. The 787-3,
which is the same length as the 787-8, accommodates 290–330 passengers
and is optimized for routes of 2,500 to 3,050 nautical miles. The longer
787-9 seats 250–290 passengers on routes of 8,000 to 8,500 nautical miles.
Boeing is currently in discussion with airlines for a possible fourth member
of the Dreamliner family, a further stretch called the 787-10.
Like the 777, the 787 Dreamliner was designed from the outset for ETOPS.
In 2007, Boeing elected to pursue 330-minute ETOPS type-design approval
under the FAA ETOPS rule of 2007 (see the next page). This 330-minute
type-design diversion authority ensures that Dreamliner operators will be
able to fly optimal routings between any two cities on earth for which their
787s have sufficient range.
February 15, 2008
ETOPS Explained
9–8
9. Boeing ETOPS Twinjet Experience (continued)
The U.S. ETOPS
rule of 2007
On February 15, 2007, the U.S. FAA enacted a major regulatory updating
that brought big changes to ETOPS. The U.S. ETOPS rule of 2007:
„ Implemented updated requirements based on the analysis of a vast
amount of enormously successful ETOPS experience by operators.
„ Applied many of the proven protections of ETOPS to further enhance
the extended operation of three- and four-engine passenger jetliners.
„ Codified ETOPS for the first time directly in the U.S. federal aviation
regulations as befits such wide-scale flight operations.
This 2007 ETOPS rule has
„ Recognized the leading safety and reliability of long-range twinjets.
„ Established the designed and certified capabilities of the airplane type
as the basis for determining that type’s maximum diversion authority.
„ Defined the maximum-allowable diversion time limit and requirements for the different regions of the world according to the specific
operational needs of each region.
„ Created the opportunity for carriers to fly properly configured and
approved twinjets on optimal flight routings between virtually any
two points on earth for which the airplane type has sufficient range.
See Section 2 for more information about the U.S. ETOPS rule of 2007.
Conclusions
February 15, 2008
This section has shown that
„ All Boeing twinjets have ETOPS-approved configurations.
„ All Boeing widebody twinjets built since the 1990s have come with
ETOPS capability as standard, because ETOPS is the state-of-the-art
in safe airplane design.
„ Boeing Next-Generation 737s are configured non-ETOPS as standard,
but ETOPS conversion after the fact is easy and inexpensive.
„ The Boeing 767 and 777 are the industry’s “ETOPS workhorses.”
„ The Boeing 777 was the first airplane designed from the outset for
ETOPS; it also pioneered Early ETOPS.
„ The super-efficient 787 Dreamliner is likewise designed for ETOPS.
„ The short-haul 717 is approved for 75-minute ETOPS and is capable
of 120-minute ETOPS.
„ The U.S. ETOPS rule of 2007 (see Section 2) has
„ Updated the requirements for twinjet ETOPS.
„ Also applied ETOPS requirements to the extended-diversion-time
of three- and four-engine passenger jetliners.
„ Provided for ETOPS beyond 180 minutes, setting the stage for
compliant operators of approved airplanes to fly optimal routings
between virtually any two cities on earth.
ETOPS Explained
9–9
Boeing ETOPS Operations Are Routine Worldwide*
Through June 2007
43,000 ETOPS flights per month
4,637,000 cumulative ETOPS flights
109 current ETOPS operators
* 737, 757, 767, and 777. Note: Besides scheduled commercial flights, this map also includes charter and some VIP ETOPS flights.
Figure 9-1
767-ET-0020•
9-19-7-DH/KW/CJ
Twins! - The Market Has Decided
All Western Commercial Jets Over 60,000 lbs Gross Weight
20,000,000
Twins
1-11
717
737-1/200
737-3/4/500
737NG
757
767
777
A300-600
A300-Early
A310
A318
A319
15,000,000
Flights
per year
Tri's
Quads
727
A320
DC-10
A321
L1011
A330
CRJ7/900 MD-11
Trident
DC9
Emb 170/190
F100
F28
MD80
MD90
Mercure
SE-210
146
146RJ
707/720
747-400
747-Early
880/990
A340
Comet
Concorde
DC8
VC-10
Twins
10,000,000
Note: From the year 2005 to 2006 Twin flights went up 5.0%.
Tri flights went down 10.8%.
Quad flights went down 6.3%.
5,000,000
Tri's
Quads
Years
Figure 9-2
2006
2004
2002
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
1980
1978
1976
1974
1972
1970
1968
1966
1964
1962
1960
1958
0
Twins consistently have lower hull loss accident rates than Quads
Hull loss accidents per million departures of all western built commercial jets over 60,000 lbs gross weight
Since the beginning
The 1970s
The last 10 years
1959 - 2006
1970 - 1979
1997 - 2006
5
5
5
4
4
4
3
3
3
2
2
2
1
1
1
0
0
0
Twins
Quad's
Twins
Quad's
1979 - 2006
0.5
Twins
Quad's
Propulsion Related Accidents
1997 - 2006
1959 - 2006
1997 - 2006
0.4
0.4
0.3
0.3
0.2
0.2
0.4
0.3
0.3
0.2
0.2
0.1
0.1
0.1
0.1
0.0
0.0
0.0
0.0
Quad's
Twins
Quad's
Twins
Figure 9-3
146*
146RJ*
707/720
747-400*
747-Early
880/990
A340*
Comet
Concorde
DC8
VC-10
* "Modern" airplanes (since 1979)
0.4
Twins
Quads
A320*
1-11
A321*
717*
737-1/200 A330*
737-3/4/500*CRJ 7/900*
DC9
737NG*
EMB 170/190
757*
F100*
767*
777*
F28
A300-600* MD80*
A300-Early MD90*
Mercure
A310*
A318*
SE-210
A319*
Modern* Airplanes only (since 1979)
0.5
Twins
Quads
Twins
Quads
The 737 Is Used For ETOPS in Many Parts of the World
Through June 2007
767-ET-0012•
9-19-7-DH/KW/CJ
Figure 9-4
The 767 Is Used Extensively For ETOPS Worldwide
Through June 2007
More than 2.8 million 767 ETOPS flights have been flown.
• 57% of the 767 operators are ETOPS operators.
Figure 9-5
767-ET-0003•
9-19-7-DH/KW/CJ
The 757 Is Used Extensively For ETOPS Worldwide
Through June 2007
318,831 cumulative 757 ETOPS flights through June 2007
4,781 757 ETOPS flights flown in June 2007
(About 160 757 ETOPS flights per day.)
• 33% of the 757 operators are ETOPS operators
Figure 9-6
767-ET-0014•
9-19-7-DH/KW/CJ
777 - Today's Most Reliable Wide-Body Jet Transport
Figure 9-7
100
777 Twin
Operational
Reliability
Percent
(Monthly Delays
>15 minutes,
Cancellations,
Air turnbacks
& Diversions)
99
A330 Twin
747-400 Quad
A340
Q d
98
Technical events only - Percent of flights without Delays >15 minutes, Cancellations, Air turnbacks & Diversions,
from respective airplane manufacturer periodic service reports.
Mar-07
Feb-07
Jan-07
Dec-06
Nov-06
Oct-06
Sep-06
Aug-06
Jul-06
Jun-06
May-06
Apr-06
Mar-06
Feb-06
Jan-06
Dec-05
Nov-05
Oct-05
Sep-05
Aug-05
Jul-05
Jun-05
May-05
Apr-05
97
Monthly rates - (Delays >15 min. + Cancellations + Air turnbacks + Diversions) / Revenue Departures. From manufacturers' respective published reports
Atlantic Crossings - US and European Airlines
As of August 2007 OAG
1000
747
900
757
767
767
800
777
A330
700
U.S. to
Europe:
weekly
600
nonstop
frequencies,
one way,
500
from August
OAG, U.S. and
400
European
airlines
A340
777
A330
747
300
200
A340
100
757
0
'77 '78 '79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06 '07
Figure 9-8
Section 10
Boeing 777 Outstation Engine
Change Experience
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained
„ Describes engine changes performed at alternate airports lacking
large-airplane maintenance facilities as a result of the propulsionrelated diversion of these three ETOPS 777 jetliners:
„ Air France (AFA) 777-200 (GE engines) diversion to Tenerife,
Canary Islands, July 1, 1998.
„ United (UAL) 777-200 (P&W engines) diversion to Yellowknife,
Northwest Territories, Canada, March 19, 2004.
„ Air France (AFA) 777-200 (GE engines) diversion to Irkutsk,
Siberia, December 17, 2005.
„ Shows how engine-change challenges were met at outstations.
„ Suggests the degree of committed support that Boeing ETOPS
operators receive from Boeing and the engine manufacturers.
„ Summarizes “lessons learned” from these outstation changes.
„ Briefly assesses the U.S. ETOPS rule of 2007’s anticipated effects
on propulsion-related diversions by twinjets as well as three- and
four-engine passenger jetliners.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
Modern fanjet engines are so reliable that propulsion-related diversions are
rare events. On average, for example, fewer than one out of every 100,000
777 ETOPS flights diverts from the ETOPS portion of flight due to engine
in-flight shutdown (IFSD) (fig. 10-1). Because IFSDs and diversions do
occasionally occur, however, the 777 and its engines are designed to minimize as much as possible the negative impacts of such service disruptions.
This section examines the first propulsion-related 777 diversion from the
ETOPS portion of flight, and two subsequent 777 wintertime diversions to
far-northerly airports. Like all airports approved for ETOPS diversion use,
these three alternates were of course properly equipped to ensure the safety
and well-being of the diverting airplane’s passengers and crew members.
(continued)
February 15, 2008
ETOPS Explained
10–1
10. Boeing 777 Outstation Engine Change Experience (continued)
Overview
(cont’d)
Unfortunately, however, none of these three airports was equipped for the
maintenance of a 777-size airplane. Quickly returning the jets to revenue
service thus presented significant challenges for airline personnel. In the
case of the AFA diversion described immediately below, personnel from
Boeing and General Electric were challenged as well.
Key lessons learned from these outstation engine changes are summarized
after the events themselves are recounted.
Description
of first event
On July 1, 1998, Air France (AFA) 777-200 F-GSPC was 6.5 hours into a
flight from Sao Paulo to Paris when its right engine quit. The flight crew
immediately diverted to Tenerife in the Canary Islands and performed an
uneventful landing one hour and twenty minutes after the failure. The
passengers were soon put on another jetliner to continue their journey.
The AOG team
The 777 landed early in the morning. By that afternoon, the first members
of an AFA airplane-on-ground (AOG) team had arrived. This AOG team
included six line maintenance mechanics from the AFA 777 fleet and one
AFA engine shop mechanic; one General Electric GE90 engine expert; and
two Boeing Customer Services engineers with expertise in 777 maintenance.
One of them had designed the 777 “bootstrap” tool used for engine changes.
About the
challenge
The stranded 777-200 had to be returned to service as quickly as possible.
Every day it sat idle meant additional disruption and more lost revenue for
its operator. Before the airplane could return to service, however, a large
engine weighing nine tons and hanging from a strut 20 feet off the ground
had to be replaced on an airfield without maintenance facilities.
This would be the 777’s first “outstation engine change,” as engine changes
are termed when not performed at fully equipped maintenance bases. AFA
and other airlines were watching with interest because of the sheer size of
the 777 engines, which are twice as big as those of other widebodies.
The 777’s
GE engines
The 777 uses the largest engines ever developed. Customers of the 777 can
choose among three different engine types: the General Electric GE90, the
Pratt & Whitney PW4000, and the Rolls-Royce Trent 800. Of these, only
the Trent (110-inch diameter) fits aboard a 747 Freighter.
To help airlines, the PW4000 (112-inch diameter) and GE90 (123-inch
diameter) are designed with removable fan cases. This innovation allows
airlines to ship replacement engines (minus their fan cases and fans) via
a 747 Freighter. This capability was used at Tenerife, where the 777’s
undamaged fan unit was mounted on an otherwise new GE90 engine.
February 15, 2008
ETOPS Explained
10–2
10. Boeing 777 Outstation Engine Change Experience (continued)
Required
equipment
A replacement engine weighing more than 13,000 pounds even without its
fan section was put aboard an AFA 747 Freighter, which altered course to
make the critical delivery. Air France borrowed the “bootstrap” required
to change the GE90 engine from Austria’s Lauda Air and flew it to Tenerife
aboard a chartered Beechcraft. A large crane was brought over from Santa
Cruz, a nearby island in the Canary group, and other tools and equipment
were located or improvised as required.
Changing
the engine
The team began by removing the damaged GE90’s unaffected fan blades
and uncowling the engine. They installed the bootstrap, raised an empty
engine stand, and fitted it to the engine, which they then disconnected from
the strut and lowered to the ground.
This new engine was then mated to the existing undamaged fan, after which
the assembled unit was raised and reattached to the wing. Completing the
repair, the fan blades and other removed components and accessories were
reinstalled and the cowling was replaced.
A successful
effort
Working 18-hour days, the team completed this repair on Sunday, July 5,
four days after the diversion occurred. Functional tests, inspection, and a
high-power ground run were followed by an hour-long test flight that same
evening during which no “squawks” were reported.
The repaired AFA 777 left Tenerife before 1 a.m. on July 6, 1998. Three
hours later it landed in Paris. By 6 a.m. that same morning, this airplane
was back in revenue service.
Lessons
learned
February 15, 2008
The Air France event described above provides experience showing that
„ The GE90—largest and heaviest of the 777’s three engine
choices—can successfully be changed by a small team at
an airport that entirely lacks suitable maintenance facilities
and equipment for a 747-size airplane.
„ Although the GE90 engine is too large in diameter for transport
aboard 747 Freighter, it can be transported via 747 provided that
the fan unit is not included.
„ Working on ground that is not completely level greatly
increases the difficulty of performing outstation engine
changes that involve the mating of engines and fans.
„ The availability of proper tooling is important and should
be carefully reviewed by each 777 ETOPS operator.
„ Safety harnesses are recommended because of the height
of the 777’s wings above the ground.
ETOPS Explained
10–3
10. Boeing 777 Outstation Engine Change Experience (continued)
Description of
second event
On March 19, 2004, United Airlines (UAL) 777-200 N783UA was cruising
at 36,000 feet over Northern Canada when it experienced a compressor stall
in its right Pratt & Whitney PW4090 engine. At the time, the 777 twinjet
was some six hours into an ETOPS flight from Frankfurt to San Francisco.
Power on the troubled engine was brought back to flight idle.
Diverting from the ETOPS portion of flight, the 777 flew to Yellowknife,
an active, well equipped airport with two runways (7,500 feet and 5,000
feet) and regularly scheduled commercial air services. Attempts to increase
power on the damaged engine resulted in additional compressor stalls, so
the right engine was left at flight idle for the remainder of the 83-minute
diversion. An uneventful landing was made at Yellowknife.
The AOG team
Even as this 777 was flying to Yellowknife, United was readying another
777 in San Francisco for passenger recovery. On board this second 777
was a UAL engine-change team with necessary equipment and an inspector.
They took off shortly after the diverting flight landed at Yellowknife.
As the launch customer for the 777, UAL has industry-leading experience
in the maintenance of this airplane type, so on-site participation by Boeing
airplane-on-ground (AOG) personnel was not requested.
About the
passengers
This flight showed that diversion can have two meanings. During their 7
hours at Yellowknife, the waylaid passengers enjoyed a bus tour of the area.
Some of their more hardy members went snowmobiling or took “ice tours.”
Their luggage was quickly transferred to the alternate 777 and they resumed
their journey with only minimal delay and many unforgettable memories.
Two main
challenges
Although Yellowknife is modern and quite well equipped, its maintenance
hangar is too small for a 777-size airplane. Moreover, it was decided that
the airport might be a bit small for a departing 747 Freighter. Therefore,
UAL decided to fly the replacement engine to Edmonton, Alberta, and then
truck it the rest of the way to Yellowknife.
This outstation engine change thus presented two main challenges:
February 15, 2008
„
Location—Yellowknife, the capital of the Northwest Territories, is on
the north side of Great Slave Lake in Canada’s far north; just one road
connects it to the outside world and the nearest major city, Edmonton,
some 600 miles (nearly 1,000 kilometers) to the south.
„
Weather—clear skies and extreme cold were the prevailing conditions,
and temperatures dipped as low as -50 deg F (-46 degrees C).
ETOPS Explained
10–4
10. Boeing 777 Outstation Engine Change Experience (continued)
Engine
transport
At the airport in Edmonton, the replacement PW4090 engine was entrusted
to the care of a trucking company. A Pratt & Whitney representative was in
attendance to oversee and advise.
The distance to Yellowknife is a roundabout 800 miles via the Mackenzie
Highway. Normally, overland cargo drives directly across the Great Slave
Lake in the winter. Traffic lanes across its thick lake ice are reinforced by
water sprayed from the Mackenzie River, creating a robust “ice bridge.”
Although the strength of the ice was not at issue, a very heavy truck will
create a bow wave beneath the ice that causes problems when it hits the far
shore. Therefore, the truck had to go around the large lake. Amazingly, it
arrived in Yellowknife after just 20 hours, having averaged 40 mph on the
journey even though the last 200 miles were by dirt road.
Equipment
required
The UAL maintenance team had brought its own equipment and supplies.
The one exception was a crane big enough to lift the large engine. Calls to
a diamond mining operation in the Yellowknife area secured a 20-ton crane.
Extremely
cold weather
Although the UAL team’s mechanics had been arctic qualified in Alaska,
Yellowknife’s weather was so cold that they found they could not uncoil
their extension cords until they were thawed out in a heated hangar. And
after using them outside, they found they could not coil them up again.
Cold weather boots did not perform well because the rubber portions froze
hard as rock. New boots had to be purchased for the team in Yellowknife.
Further slowing progress, there were only about 10 hours of daylight.
Successful
conclusion
The stranded 777’s passenger cabin had been kept warm throughout its stay
at Yellowknife to prevent damage. Six-and-a-half days after it arrived, the
jetliner departed Canada with a new right engine and UAL’s veteran team
aboard. This airplane was immediately returned to service.
Lessons
learned
In addition to underscoring the engine-change lessons learned at Tenerife,
United’s 777 outstation experience at Yellowknife
„ Demonstrated the value of being prepared with a well
defined and executed passenger recovery plan.
„ Brought to light unexpected issues that can delay engine
changes performed outdoors in extremely cold weather.
„ Drove home the importance of having the right equipment
and clothing for the job.
February 15, 2008
ETOPS Explained
10–5
10. Boeing 777 Outstation Engine Change Experience (continued)
Description
of third event
On December 17, 2005, Air France 777-200 F-GSPO was a little more than
three hours into a 12-hour ETOPS flight from Seoul to Paris when the right
engine failed. The ETOPS portion of flight had not yet been entered.
The 777 diverted to Irkutsk, Siberia, this being the nearest alternate airport,
and landed 40 minutes later. The passengers deplaned, spent the night in a
comfortable hotel, and continued to Paris the next day on another airplane.
Meantime, AFA personnel undertook a challenging engine change made all
the more memorable by bitter cold, a snow storm, the lack of a hangar in
which to work, and customs and visa issues. The engine was successfully
replaced at Irkutsk and the 777 was returned to service within two weeks.
Lessons
learned
Air France’s 2005 diversion to Irkutsk
„ Highlighted a need for negotiated understandings in advance with
the governments in whose territories an airline’s diversion airports
lie, so that unexpected obstacles do not arise—in this case, customs
for passengers and the arriving repair team, visas for this team, and
approval for a special flight to retrieve the stranded passengers.
„ Showed the wisdom behind some airlines’ purchase of inflatable
temporary hangers, which allow engine changes in inhospitable
climates to be performed in a controlled environment.
„ Served as a reminder that equipment at diversion airports is not
compatible with western standards—adapters may be required
for tire inflation connections, electrical power outlets, and so on.
Conclusions
When the 777 was new to service, some airlines expressed concerns about
outstation engine changes. These concerns centered on the unprecedented
size of this twinjet’s engines, which might limit their air transportability to
stranded 777s following propulsion-related diversions.
Experience gained by the industry since the 777 entered service in 1995—
including the three outstation engine changes described above—has served
to reassure operators that 777 engines can indeed be replaced at outstations
and that airplanes can be returned to revenue service in a timely manner.
February 15, 2008
ETOPS Explained
10–6
Most 777 Inflight Shutdowns (IFSDs) Occur
Outside the ETOPS Portion of Flight
June 1995 through June 2007
A summary of 77 IFSDs out of
1,024,600 777 ETOPS flights.
Only 8 (10%) occurred in the
ETOPS portion of flight. IFSD
rate on these 777 ETOPS
flights is approximately 0.004
per 1,000 engine flight hours.
ETOPS portion
0
Continue
0 Continue
0
Air Turnbacks
27
Air Turnbacks
Departure
(1,024,600 Flights)
20
Diversions
8
Diversions
Alternate
Airport
9
Diversions
Alternate
Airport
13
Continue
Destination
Less than one out of 100,000 ETOPS flights diverted from the ETOPS portion of flight due to engine IFSD.
777EIFSD-C.cvs
Figure 10-1
Section 11
ETOPS Flight Crew Training
Requirements
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained observes that
„ ETOPS requires some ground training for flight crews.
„ ETOPS does not require any additional flight training.
„ Many airlines elect to familiarize their crews through simulator
training with operational procedures and alternate airports they
might someday need to use.
„ Consequently, ETOPS flight crew training requirements
represent a very moderate additional cost to operators.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Ground training
is required
ETOPS requires flight crews to receive about four hours of ground training.
This training serves to familiarize pilots with the ETOPS program and its
requirements. Among the elements addressed are
„ ETOPS flight planning and the concept of equal-time points.
„ Diversion regulatory requirements as well as factors to be
considered in the diversion decision-making process.
„ Flight progress monitoring and fuel tracking, both of which are
more important in ETOPS than for conventional flight operations.
„ The ETOPS minimum equipment list (MEL).
In addition, if the operator plans to perform either polar ETOPS or beyond180-minute ETOPS, both of which are provided for under the U.S. ETOPS
rule of 2007, additional ground training is required for flight crews. This
training focuses primarily on the passenger recovery plans that air carriers
must develop for the alternate airports on which these polar or beyond-180minute ETOPS operations will rely.
Also depending on the operation, flight crews may need ground instruction
on the use of SATCOM, which is required for 207-minute ETOPS but not
for ETOPS at or below 180 minutes. See Section 2 for more information
about the 2007 ETOPS rule and its requirements.
February 15, 2008
ETOPS Explained
11–1
11. ETOPS Flight Crew Training Requirements (continued)
ETOPS flight
training is
optional for
air carriers
In contrast, the ETOPS program does not specifically require flight training
because no ETOPS-unique piloting skills exist that need to be taught or
practiced. Regardless of whether an airplane is performing ETOPS or not,
its flight crew operates it identically in terms of flying skills.
Although ETOPS-specific flight training is not required, many air carriers
conduct ETOPS simulator training using the line-oriented flight training
(LOFT) scenario. LOFT is a realistic training approach that
„ Further familiarizes flight crews with ETOPS planning.
„ Acquaints them with operational procedures and the alternate airports
they may someday use.
„ Prepares crews for long-range international operations.
LOFT closely replicates actual airline operations. A typical ETOPS LOFT
simulator training session might require a crew to follow an existing flight
plan, declare an emergency, divert to an alternate airport, and land there.
Recurrent training also provides opportunities for flight crews to keep up
with ETOPS requirements, alternate airports, and procedures.
In addition, some carriers employ supervised line flying (SLF) as a way to
expose pilots with little ETOPS experience to operational procedures and
decision-making processes on actual ETOPS missions before turning them
loose to fly ETOPS.
Conclusion
February 15, 2008
The following conclusions can be drawn about ETOPS flight crew training
requirements:
„ The ETOPS program requires flight crews to conduct some training, but
does not specifically require flight training.
„ No ETOPS-unique piloting skills exist that would need to be taught
or practiced.
„ Consequently, total ETOPS-related flight crew training costs are not
a significant cost factor for ETOPS operators.
„ Many airlines elect to include ETOPS diversion and alternate-airport
landing scenarios during simulator training to familiarize their flight
crews with operational procedures and the alternate airports on which
their ETOPS services rely.
ETOPS Explained
11–2
Section 12
ETOPS Maintenance and
Configuration Requirements
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of ETOPS Explained describes ETOPS maintenance and
configuration requirements as defined, respectively, by the
„ ETOPS Continuous Airworthiness Maintenance Program (CAMP).
„ ETOPS Configuration, Maintenance, and Procedures (CMP) document,
which is specific to each ETOPS airplane.
Under an ETOPS CAMP, ETOPS twinjet operators are required to perform
additional preventive maintenance tasks over and above those they would
normally perform on their airplanes. This section describes these ETOPS
CAMP maintenance requirements.
ETOPS configuration requirements ensure that ETOPS twinjets incorporate
design enhancements that make engines and significant systems less likely
to fail in flight. ETOPS configuration requirements also address operational
safety through increased cargo fire suppression capability and, for beyond180-minute ETOPS, enhanced communications capability.
Under the U.S. ETOPS rule of 2007, operators of three- or four-engine
passenger jetliners are today also subject to ETOPS when they fly routes
that take their airplanes beyond 180 minutes of an airport (see Sections 2
and 4). Although the 2007 ETOPS rule exempts these existing “tri and
quad” operators from ETOPS maintenance requirements, some of them
voluntarily perform many ETOPS maintenance procedures on their fleets
(tri and quad freighter operators are exempted from the 2007 ETOPS rule).
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
February 15, 2008
Flown since 1985, ETOPS is the global framework under which the world’s
airlines routinely fly twinjets on routes that at some point take the airplane
beyond 60 minutes of an alternate airport. At the heart of ETOPS is a dual
preclude and protect philosophy that (1) reduces the rate at which engines
and critical systems fail in flight, thereby preventing many airplane-related
diversions, and (2) further protects the airplane, its passengers, and its crew
if a diversion does occur.
(continued)
ETOPS Explained
12–1
12. ETOPS Maintenance Requirements (continued)
Overview
(cont’d)
ETOPS maintenance and configuration requirements are the two drivers
that the ETOPS program uses to preclude many diversions. They explain
much of the success of ETOPS.
Of course, ETOPS also employs operational requirements that serve to
further protect the airplane and its occupants should a diversion occur.
See Sections 1, 2, and 8 of ETOPS Explained for information about these
ETOPS operational requirements, which are not discussed in this section.
About ETOPS
maintenance
& configuration
enhancements
Among the ways that ETOPS makes extended operations safer are
„ Preventive maintenance—a focus on prevention helps maintenance
technicians identify and address many issues before they can trigger
an airplane diversion or other service disruption. ETOPS maintenance
training also focuses on disciplined condition and fluid-level monitoring.
„ Enhanced airplane configuration—ETOPS configuration requirements
have made engines and other airplane systems more robust, reducing the
rate at which ETOPS twinjets divert for airplane-related reasons.
Operators can find their applicable ETOPS maintenance and configuration
requirements in
„ U.S. federal aviation regulation 14 CFR 121.374, or the equivalent
non-U.S. regulation, which defines the Continuous Airworthiness
Maintenance Program (CAMP) required for two-engine ETOPS.
„ Each ETOPS twinjet’s Configuration, Maintenance, and Procedures
(CMP) document, which lists all the ETOPS requirements applicable
to that specific airplane type (airframe / engine combination).
Specific
requirements
An ETOPS CAMP enhances operational safety and reliability through
proven ETOPS maintenance practices that include
„ Engine condition monitoring.
„ Oil consumption monitoring.
„ Preventive engine and systems maintenance training.
„ A prohibition against a single maintenance technician working on
both engines, or both the left and right sides of a redundant ETOPS
significant system, during a single maintenance session.
As for an ETOPS CMP, it defines an ETOPS-unique airplane
configuration that yields increased reliability through
„ Airplane systems enhancements.
„ Enhanced cargo fire suppression capability and, for ETOPS
beyond 180 minutes, enhanced communications capability.
„ An ETOPS-specific Minimum Equipment List (MEL).
February 15, 2008
ETOPS Explained
12–2
12. ETOPS Maintenance Requirements (continued)
Engine
condition
monitoring
An ETOPS CAMP implements procedural reliability enhancements. One
example is engine condition monitoring, an ETOPS maintenance practice
in which operators monitor engine operating temperatures, bleed control
signatures, and other health-indicating engine parameters and functions.
Engine condition monitoring allows operators to detect early deterioration
of engines, track this deterioration, and take corrective action before normal
airplane operation is affected.
Data analysis shows that engine condition monitoring more than pays for
itself by reducing engine IFSD rates. Airlines know that IFSDs are costly
and disruptive events whose consequences are magnified as they propagate
through the carrier’s route network, causing flight connections to be missed.
Consequently, engine condition monitoring is an ETOPS “best practice” that
airlines often voluntarily implemented in their non-ETOPS fleets.
Oil consumption
monitoring
Closely monitoring engine and auxiliary power unit (APU) oil levels and
consumption rates is perhaps the simplest and most effective of the many
safety-enhancing ETOPS maintenance procedures. This oil consumption
monitoring is incorporated into the transit check that all airlines perform
before the departure of every flight.
Because increased scrutiny of oil levels and consumption rates translates
directly into fewer IFSDs, many ETOPS operators are today performing
oil consumption monitoring across their entire fleets, regardless of whether
or not ETOPS is being flown.
Checking engine and APU oil levels and calculating consumption rates are
parts of the standard ETOPS pre-departure check. See other aspects of the
ETOPS pre-departure check later in this section.
Preventive
engine and
systems
maintenance
training
Preventive engine and systems maintenance training offers yet another way
for airlines to identify potential problems before they trigger a costly service
disruption. It teaches their maintenance technicians where to look for signs
of deterioration in the wiring and tubing around an engine.
Identifying potential “inside the cowling, outside the engine” trouble spots
increases the value of visual inspections by arming technicians with
precise knowledge of where to look. For example, deterioration frequently
occurs where wire bundles encounter “hot spots,” insulation is subject to
chafing, or tubing vibrates.
This heightened effectiveness of visual inspections has brought about what
one airline calls a “deterioration-intercept mentality.” Not surprisingly,
many carriers also apply this ETOPS “best practice” to further enhance the
operational reliability of their non-ETOPS fleets.
February 15, 2008
ETOPS Explained
12–3
12. ETOPS Maintenance Requirements (continued)
Left- and
right-side
maintenance
prohibition
ETOPS maintenance procedures avoid having one technician perform the
same significant maintenance task on both the left- and right-side airplane
systems (engines in particular) during a single maintenance session. This
prohibition ensures that improperly performed maintenance tasks will not
compromise the functioning of both engines or both sides of a redundant
ETOPS significant system. ETOPS allows operators to either (1) have a
different maintenance technician work on each side of the jetliner; (2) have
one technician do both sides provided a second technician then reviews the
work; or (3) have one technician do all the work under the guidance of the
maintenance control center. All three options require verification to ensure
the effectiveness of actions taken on ETOPS significant systems. Option 3
also requires verification during flight prior to the ETOPS entry point.
Beginning in 1990, some air carriers incorporated this procedural safety
enhancement by splitting the “A” Check for their 767 ETOPS fleets into
two separate checks, one dedicated to each side of the airplane (some
airlines subsequently extended this safety-enhancing policy to their other
fleets as well). When it is not possible to avoid significant work on both
sides of an airplane in a single maintenance session, some carriers require
verification ground testing before returning the airplane to ETOPS service.
ETOPS
data sharing
ETOPS reliability—and aviation safety in general—is further enhanced by
ETOPS data sharing. To help ETOPS operators, the airplane and engine
manufacturers routinely gather and share information about engine in-flight
shutdowns (IFSD), significant system failures, diversions and air turnbacks,
and other reliability-related events. Analysis of this real-world operational
data allows root causes to be identified and corrected, undesirable trends to
be addressed early on, and overall reliability improvements to be achieved.
About the
ETOPS CMP
All ETOPS airplane and engine configuration requirements are listed in the
ETOPS airplane’s CMP. By adhering to a CMP, an operator can know that
the airplane’s configuration remains consistent with its ETOPS type-design
approval. When an air carrier acquires an airplane for ETOPS, its approved
CMP defines the configuration required for ETOPS operations. Subsequent
CMP revisions do not apply to this operator or airplane unless mandated by
an Airworthiness Directive (AD).
As more and more airplanes are designed for ETOPS, the configurational
differences between ETOPS and non-ETOPS examples are shrinking. For
example, 777s, Next-Generation 737s, 787s, and newer 767s need very few
changes to fly ETOPS because they are built already incorporating almost
all ETOPS enhancements (non-ETOPS versions let non-ETOPS operators
avoid the extra weight of upgraded cargo-fire suppression systems).
(continued)
February 15, 2008
ETOPS Explained
12–4
12. ETOPS Maintenance Requirements (continued)
About the
ETOPS CMP
(cont’d)
Today’s comparative ETOPS configurational ease came about because the
commercial aviation community in the 1980s and early 1990s took a hard
look at engine and systems reliability to see where further reliability gains
could be made in support of ETOPS. Initially focusing on engines, that
concerted effort led to the redesign of many airplane systems components
to make them more robust.
At the start of the ’90s, for example, United Airlines reduced the IFSD rate
of its Boeing 767-200 ETOPS fleet by installing fuel pumps redesigned to
prevent engine flameouts resulting from interruptions in the fuel flow. So
successful was this cost-saving ETOPS reliability enhancement that United
also implemented it in its fleet of early-model 747s, which used the same
JT9D engines as its 767-200s.
About
ETOPS
airplanes
A TWA 767 performed the first ETOPS flight in 1985 under U.S. Federal
Aviation Administration (FAA) Advisory Circular AC 120-42 guidelines.
Although the 767 twinjet came into being before ETOPS and was thus not
designed for it, 767s pioneered ETOPS and have logged roughly half of all
ETOPS flights. Today, 767s and 777s are the backbone of ETOPS flying
worldwide (see Sections 1, 3–6, 8, and 9 of ETOPS Explained).
Unlike the 767, the 777, Next-Generation 737, and 787 Dreamliner twinjets
were designed from the outset for ETOPS. So is the 747-8, which of course
is a major derivative of the four-engine 747. All these Boeing commercial
airplanes combine ETOPS capability with reliability that equals or exceeds
that of the pioneering 767.
ETOPS predeparture
checks
When ETOPS began, the pioneering twinjet operators devised extremely
conservative pre-departure checks that in some cases took them two hours
to perform. After a few years of ETOPS experience, they asked Boeing to
review the data and assess the value of these checks from an ETOPS safety
and reliability perspective.
Preliminary Boeing analysis revealed little correlation between what these
carriers were individually doing and consequent ETOPS reliability. Further
analysis proved that the ETOPS pre-departure check could be improved by
focusing just on those practices shown to enhance an airplane’s ability to
perform an extended diversion. In this manner, superfluous checks were
eliminated and those that remained were evaluated according their specific
contributions to ETOPS reliability. At its conclusion, this study showed
that, with only minor modification, the routine checks that airlines perform
at the start of the day and before each flight suffice as a full pre-departure
ETOPS maintenance check.
(continued)
February 15, 2008
ETOPS Explained
12–5
12. ETOPS Maintenance Requirements (continued)
ETOPS predeparture
checks
(cont’d)
The U.S. ETOPS Rule of 2007 lists minimum requirements for this ETOPS
pre-departure service check in regulation 14 CFR 121.374 (b). ETOPSsignificant airplane systems must be checked and applicable maintenance
records must be reviewed. Oil levels and oil consumption rates must be
determined for the engines and APU.
About
the ETOPSspecific MEL
All jetliners have a minimum equipment list (MEL) that dictates when issues
with the jet’s systems preclude or limit dispatch. ETOPS requires twinjets
to have a modified MEL with conservative dispatch requirements. Even so,
Boeing data analysis shows that ETOPS-specific MELs have little impact on
schedule interruptions or overall maintenance requirements.
The U.S. ETOPS
rule of 2007
On February 15, 2007, the U.S. FAA enacted a major regulatory updating of
ETOPS (see Section 2). Referred to above in this section, the U.S. ETOPS
rule of 2007
„ Implemented requirements updated according to the analysis of facts
and data compiled over more than two decades of highly successful
ETOPS twinjet flying worldwide.
„ Applied proven ETOPS requirements more broadly to also embrace
the operation of three- and four-engine passenger jetliners on routes
with the potential for an extended-duration diversion.
„ Has provided for ETOPS beyond 180 minutes, setting the stage for
compliant operators of approved twinjets and other airplanes to fly
optimal routings between virtually any two cities on earth for which
the airplane has sufficient range.
Under this 2007 ETOPS rule, three- and four-engine ETOPS operators
„ Are not required to establish an ETOPS CAMP—the FAA leaves it
up to the tri or quad operators as to whether they wish to bring their
ETOPS fleet maintenance up to ETOPS levels or not.
„ Must meet two ETOPS airplane configuration requirements
„ Cargo fire suppression—operators must upgrade the cargo fire
suppression systems of their tri and quad ETOPS passenger jets.
„ Communications—operators must install satellite communication
(SATCOM) voice communications capability in their tri and quad
ETOPS fleets; another form of communication must also be available.
The 2007 ETOPS rule has granted affected tri and quad ETOPS operators
six (6) years, ending February 15, 2013, to bring their existing fleets into
compliance with the cargo fire suppression requirement. See Sections 2
and 4 for insights about tri and quad operations and the impact on current
operators of the ETOPS rule of 2007.
February 15, 2008
ETOPS Explained
12–6
12. ETOPS Maintenance Requirements (continued)
About ETOPS
maintenance on
tris and quads
As stated, under the 2007 ETOPS rule, an ETOPS CAMP is required for
twinjets but not for three- or four-engine passenger jetliners when they fly
ETOPS. As the FAA explains in the preamble to this 2007 rulemaking:
The FAA strongly believes that all operators would benefit from an
ETOPS maintenance program. However, the FAA agrees with many of
the commenters that the cost of implementing this new requirement for
airplanes with more than two engines would be significant. The FAA
has determined that this cost cannot be justified based on the current
level of safety achieved by the combination of engine reliability and the
engine redundancy of this fleet of airplanes. 1
Therefore, even though Boeing and some operators share the FAA’s belief
that all ETOPS operators would benefit from an ETOPS CAMP, the 2007
ETOPS rule nevertheless allows operators of passenger jetliners with more
than two engines to decide for themselves whether or not to implement this
CAMP. As for tri and quad freighter operators, the 2007 rule exempts them
entirely from ETOPS.
Conclusions
The ETOPS CAMP is what any good airplane maintenance program should
be. It reduces the rate of airplane propulsion and system failures through
disciplined maintenance procedures like engine condition monitoring, oil
consumption monitoring, additional training that teaches technicians how
to spot incipient problems, the aggressive resolution of identified reliability
issues, and procedures to avoid human error during scheduled maintenance.
Data analysis confirms that an ETOPS CAMP effectively reduces costs and
simplifies operations by reducing the rate at which IFSDs and other system
failures occur that can cause diversions and other service disruptions. As a
result, it is quite common to find air carriers applying ETOPS maintenance
practices to non-ETOPS fleets. ETOPS maintenance is required for ETOPS
twinjet operations. In contrast, the 2007 ETOPS rule makes it optional for
tri and quad ETOPS operations.
ETOPS configuration requirements are listed in each ETOPS airplane’s
CMP document. Under the ETOPS rule of 2007, three- and four-engine
passenger airplanes that fly ETOPS airplanes will be subject to two ETOPS
configuration requirements (increased cargo fire suppression capacity and
SATCOM voice communications). This rule grants operators compliance
windows of six years and one year, respectively, to mitigate the costs of
meeting these configuration requirements.
1
U.S. Federal Register, Washington, DC, vol. 72, no. 9, January 16, 2007, p. 1836.
February 15, 2008
ETOPS Explained
12–7
Section 13
ETOPS Economics
ETOPS Explained, by Boeing Commercial Airplanes
Summary
In briefly assessing the economics of ETOPS, this section
„ Observes that the global success of ETOPS attests to the fact that it is
a cost-saving program—it would not succeed if it did not ultimately
deliver net positive economic value to airlines and their passengers.
„ Shows that ETOPS offers economic benefits to operators in three areas:
„ Increased market flexibility. „ Reduced economic risk.
„ Reduced operating costs.
„ Identifies and assesses the costs of ETOPS to operators in these areas:
„ Airplane configuration.
„ Spares provisioning.
„ Regulatory approval.
„ Maintenance (twinjets only).
„ Flight operations.
„ Briefly reviews economic aspects and implications of the U.S. ETOPS
rule of 2007, which opens up the world to ETOPS twinjets, and applies
selected ETOPS requirements more broadly to also embrace extended
operations by three- and four-engine passenger jetliners (see Section 2
for more about the 2007 ETOPS rule, and Section 4 for an assessment
of how it affects existing tri and quad operations).
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
The success of ETOPS since 1985 has shown the world that two-engine
jetliners, or twinjets, are well suited to long-haul flight operations on routes
with the potential for an extended-duration diversion to an alternate airport
(see the Introduction and Sections 1 and 3). ETOPS twinjet operations over
more than two decades have also demonstrated the exceptional safety and
reliability of two-engine jets.
Important as safety and reliability are, however, they didn’t drive the world
to embrace ETOPS. Instead, it is the economics of ETOPS that explain its
success. ETOPS is the global regulatory framework under which operators
fly twinjets on extended-diversion-time air routes. As such, it lets carriers
and their passengers benefit from the economic advantages of twinjets on
routes with the potential for an extended-duration diversion to an alternate
airport (see Introduction, Section 1, and Section 8).
(continued)
February 15, 2008
ETOPS Explained
13–1
13. ETOPS Economics (Continued)
Overview
(cont’d)
While all commercial jet transports are safe, twinjets as a category are the
safest and most reliable of all. They use less fuel, create fewer emissions,
come in more sizes, and can operate at more airports around the world. As
a result, twinjets are the industry standard. In fact, more than 90 percent of
jetliners delivered today are twins, and new jetliners are only designed with
more than two engines when two would not provide sufficient thrust due to
limitations in engine technology.
The success of ETOPS itself shows that the economic advantages of twinjet
extended operations outweigh the associated cost burden of ETOPS. This
burden falls in three areas: airline operations, airline maintenance, and
airframe / engine type design. Because the economic burden of type design
is primarily born by airplane and engine manufacturers, this section will
focus entirely on operations and maintenance (primarily the former).
On February 15, 2007, the U.S. Federal Aviation Administration (FAA)
enacted a comprehensive regulatory updating of ETOPS that provides for
ETOPS beyond 180 minutes, setting the stage for twinjet operators to fly
direct routings between virtually any two cities on earth. Beyond 180
minutes, this rulemaking also applies ETOPS more broadly to further
enhance three- and four-engine passenger airplane extended operations.
The U.S. ETOPS rule of 2007 provides a regulatory framework by which
compliant operators can fly any direct routing in the world for which their
approved airplanes—twinjets included—have sufficient range. This rule
thus opens up new opportunities for air carriers as they continue to exploit
the leading efficiency and reliability of today’s long-range twinjets in longhaul markets. Because twinjets come in more sizes, this ETOPS rule also
greatly enhances airline opportunity to flexibly pursue individual business
strategies that maximize value for themselves and their passengers.
Relatively few routes in the world have diversion times that exceed three
hours. The 2007 ETOPS rule mitigates risks by applying selected ETOPS
requirements to three- and four-engine passenger airplanes when they fly
these challenging routes. These proven ETOPS operational protections add
only minor cost. Tri and quad passenger operators are exempted from the
2007 rule’s ETOPS maintenance requirements, and tri and quad all-cargo
operators are exempted entirely from ETOPS (see Section 2).
Observations
about twins,
tris, and quads
February 15, 2008
A 1953 regulation limited two-engine airliners to routes that did not take the
airplane beyond one hour’s flying time, at single-engine cruise speed, of the
nearest en route alternate airport. For many years, this operating restriction
kept airlines from realizing the economic benefits of modern twinjets on
long overwater or other challenging routes. In the past, the limited range
of twinjets also kept them confined primarily to continents.
(continued)
ETOPS Explained
13–2
13. ETOPS Economics (Continued)
Observations
about twins,
tris, and quads
(cont’d)
In 1985, the ETOPS program provided the world’s airlines with a way to
safely fly twinjets beyond one hour of a suitable en route alternate airport.
Based on the analysis of facts and data, this conservative, evolutionary
program has preserved or enhanced safety while making available to the
world’s airlines progressively greater maximum diversion authorizations.
As a result, air carriers have been able to operate fuel-efficient twinjets on
more-direct flight routings between a rising number of city pairs around the
globe. Progressively longer ETOPS diversion times have also simplified
twinjet extended operations by reducing the number of ETOPS alternate
airports required to support these flight operations.
In contrast, for many decades, four-engine airliners in particular—which
have never been subject to a regulatory operating restriction—offered the
greatest range capability. Before 2007, moreover, three- and four-engine
jets were not subject to ETOPS. Consequently, long-haul flight operations
around the world were pioneered largely by four-engine airplanes.
As jetliner range capabilities have grown over the decades, commercial
flight operations have increasingly overflown remote parts of the world.
A few of these long intercontinental routes have exposed air travelers to
risks that ETOPS can reduce. Consequently, the FAA has included threeand four-engine passenger jetliners in its regulatory updating of ETOPS.
The economic penalty that the ETOPS rule of 2007 imposes on three- and
four-engine passenger operators is small and closes a gap in safety.
In 2000, four-engine jetliners were making 32 percent more long flights 1
than twinjets around the world. By 2003, quads and twins were making
about the same number of long flights. By 2007, twins had taken the lead,
accounting for 75 percent more long flights than quads (fig. 13-1). This
rapid transition to twinjets worldwide is primarily the result of the superior
economics of long-haul twinjets, which ETOPS and twinjet safety together
make available for extended-diversion-time operations.
Specific
ETOPS
economic
benefits
1
Making twinjets available on air routes with the potential for an extendedduration diversion may be the primary economic benefit of ETOPS, but it
is by no means the only one. Among its other economic benefits, ETOPS
„ Reduces schedule interruptions because twinjets hold to schedule
better than do tris or quads (fig. 13-2)—twinjets demonstrate the
„ Highest dispatch reliability, meaning fewer airplane-related
delays than other categories of jetliner.
„ Lowest rate of air turnbacks to the airport of origin and
diversions to en route alternate airports.
(continued)
Defined as a scheduled flight of 8 hours or more as listed in the August Official Airline Guide.
February 15, 2008
ETOPS Explained
13–3
13. ETOPS Economics (Continued)
Specific
ETOPS
economic
benefits (cont’d)
About market
fragmentation
„
„
Reduces the severe economic consequences of service disruptions propagating through their route networks as connecting flights are missed.
Allows smaller capacity twinjets to fly long-haul and very-long-haul
routes, creating new revenue opportunities by letting airlines
„ Serve existing markets more frequently for higher passenger
satisfaction through more travel options and better connections.
„ Pioneer new markets with insufficient total travel demand for
profitable service by large four-engine jetliners.
„ Directly link more of the world’s population centers, including
services to secondary airports too small for four-engine jets.
As the above suggests, ETOPS and the capabilities of newer airplanes—
together with the ongoing liberalization of air markets around the world—
have ushered in a profound transformation of global air service patterns.
Called market fragmentation, this trend makes air travel more direct and
convenient. It is continuing to transform how the world flies.
Airlines were quick to exploit the new opportunities offered by ETOPS.
As of 2007, twinjets account for more than 70 percent of all flights across
the North Atlantic, and 45 percent of all long-range North Pacific flights.
See Sections 5 and 6 respectively for more information about these key
intercontinental air markets and the market fragmentation that lets airlines
exploit new opportunities, enhance revenues, and deliver greater value.
Three areas
of ETOPS
economic
benefits
ETOPS offers operators economic benefits in three areas:
„ Lower operating costs—ETOPS makes available the superior fuel
efficiency of long-haul twinjets on extended-diversion-time routes.
„ Increased market flexibility—long-haul twinjets come in more sizes,
allowing operators to more closely match airplane capacity to market
demand. Flying fuel-efficient, smaller capacity airplanes also allows
operators to serve existing markets more frequently, and pioneer new
services to more total airports.
„ Reduced economic risk—ETOPS reduces airline risk exposure through
greater profitability, higher passenger satisfaction, superior market
flexibility, increased ability to adapt as travel demand shifts, and lower
initial capital investment because twinjets cost less to acquire.
Lower operating
costs
Twinjets are the most economical jets. They consume less fuel (fig. 13-3),
create fewer emissions, and cost less to maintain than do jets with more
engines. Twinjets are also structurally more efficient, with lower operating
empty weights per passenger seat than tris and quads. As a result, more than
95 percent of all new jetliners delivered in 2006 were twinjets (fig. 13-4).
February 15, 2008
ETOPS Explained
13–4
13. ETOPS Economics (Continued)
Increased
market
flexibility
Large widebody jets with three or four engines were once the mainstay of
long-haul air travel. Then, beginning in the 1980s, fuel-efficient twinjets
appeared on the scene that combined long range with smaller passenger
capacities. Exploiting these new capabilities, the world’s airlines began
delivering greater value to passengers by flying nonstop ETOPS and other
long-haul services that bypassed traditional hubs to directly link a much
larger and still growing number of the world’s population centers.
ETOPS helps airlines succeed through this increased market flexibility,
which provides additional revenue opportunities and makes flying more
direct and convenient for business and other travelers (fig. 13-1).
Reduced
economic risk
When market conditions are uncertain or volatile, flying ETOPS twinjets
can reduce an airline’s exposure to economic risk by increasing its ability
to adapt to seasonal and other shifts in travel demand.
For example, a fleet of 20 intermediate-capacity ETOPS twinjets with 250
seats each may offer the same total number of seats as 10 jumbos with 500
seats each. However, adapting to change is far easier with the former fleet
because considerably more and better options exist if the need should ever
arise to redeploy airplanes within the airline’s route network.
Quantifying
ETOPS benefits
is difficult
Assessing the economic costs and benefits of ETOPS is difficult because
„ Each airline’s situation differs in terms of route structure, operating
environment, internal policies, and accounting methods.
„ It is impossible to say how or to what degree the benefits of ETOPS
translate into money—for example, how does one ascribe a monetary
value to service disruptions precluded by ETOPS engine and systems
reliability enhancements?
„ An accounting system that tracks all available statistics per flight will
inevitably ignore pertinent factors, such as heightened satisfaction and
brand loyalty on the part of frequent fliers who value the direct travel
and more conveniently timed services that ETOPS makes possible.
„ Airline financial information is proprietary—for example, the actual
amount an airline pays for its airplanes is a closely guarded secret.
ETOPS
cost factors
Compared to the benefits described above, the costs to operators of ETOPS
are relatively minor. These ETOPS costs occur in five areas:
„ ETOPS maintenance (twinjets only).
„ Airplane configuration.
„ Regulatory approval.
„ Spares provisioning.
„ Flight operations.
February 15, 2008
ETOPS Explained
13–5
13. ETOPS Economics (Continued)
Airplane
configuration—
twinjets
Twinjets—depending on the model Boeing twinjet, little or no additional
customer investment is required in terms of airplane configuration before
the customer can take delivery and perform ETOPS. The reason is that all
Boeing twinjets today in production are delivered either ETOPS ready or
ETOPS capable. For example, these twinjets are delivered ETOPS ready:
„ 777—standard configuration approved for 180-minute ETOPS. Some
models expect to have 330-minute options available soon.
„ 767—standard configuration approved for 180-minute ETOPS. May
be extended to 207 minutes for North Pacific operations.
And these Boeing jets are delivered ETOPS capable:
„ Next-Generation 737—180-minute ETOPS capability is available to
customers as a standard option.
„ 717—currently approved for 75-minute ETOPS, this short-haul
twinjet could be extended to 120 minutes if operators request it.
The Boeing 787 Dreamliner will also be delivered ETOPS capable. This
all-new twinjet was designed for a maximum diversion authorization of 330
minutes to ensure that compliant ETOPS operators can fly optimal routings
between any two cities on earth for which their 787s have sufficient range.
Airplane
configuration—
four-engine jets
Four-engine jetliners—the 747-400 is scheduled to fall out of production
around 2011. It will not require ETOPS type-design approval because,
under the terms of the ETOPS rule of 2007 (see Section 2), only currentproduction jetliners still in production as of February 17, 2015, will have
to incorporate ETOPS design changes in order to fly ETOPS.
For 747 operators who are subject to ETOPS because they fly passenger
versions of this jumbo jet beyond three hours of an airport, the primary
configuration cost is the requirement to upgrade the cargo fire suppression
capability of their 747 ETOPS fleets. The ETOPS rule of 2007 grants these
operators 6 years, ending February 15, 2013, to meet this requirement (see
Sections 2 and 4).
The Boeing 747-8 Intercontinental will have ETOPS type-design approval
for up to 330-minute ETOPS. This capability is available as an option for
customers of the 747-8.
About
aftermarket
modification
February 15, 2008
Modifying twinjets already in service to perform ETOPS can be expensive
if Boeing did not originally deliver these airplanes for ETOPS. This is true
in particular for aftermarket modification of the 757 and 767. For example,
a hydraulic motor generator must be installed and associated modifications
must be made to the hydraulic and electrical systems to achieve the level of
electrical system redundancy required for ETOPS.
ETOPS Explained
13–6
13. ETOPS Economics (Continued)
Airplane
configuration
observations
When discussing the ETOPS configuration costs of new Boeing airplanes,
it should be observed that:
„ Over time, Boeing and other manufacturers have folded ETOPS
safety and reliability enhancements into their original airplane
and engine designs, making ETOPS levels intrinsic rather than
added on.
„ Because most Boeing Next-Generation 737s operate in domestic
service, ETOPS is a standard option
„ Boeing chose not make ETOPS standard to avoid imposing a
weight penalty on the majority of operators, who do not need
increased cargo-fire-suppression capability.
„ Converting a Next-Generation 737 twinjet from non-ETOPS to
ETOPS configuration, or vice-versa, is simple and inexpensive.
„ The Boeing 787 Dreamliner—like the 777 before it—has been
designed from the outset for ETOPS capability.
„ The Boeing 747-400 and new 747-8 Intercontinental have simple
options available for ETOPS up to 330 minutes.
Note that the 757 and 767 are being replaced by the 787 Dreamliner, and
that the 717 and 757 twinjets are no longer in production.
ETOPS
operational
approval
The process by which an air carrier new to ETOPS obtains its ETOPS
operational approval (i.e., regulatory approval to fly ETOPS) typically
begins many months before it takes delivery of its first ETOPS airplane.
This process starts with the airline creating a dedicated multi-departmental
ETOPS committee that works with the applicable regulatory agency and
other parties, such as third-party vendors, to lay the requisite groundwork.
To obtain its ETOPS operational approval, the air carrier must also establish
an ETOPS flight operations program, develop the required documentation,
conduct initial ETOPS training, and so on. Moreover, twinjet operators
must establish an ETOPS continuous airworthiness maintenance program
(CAMP) whereas tri and quad ETOPS operators are exempted from ETOPS
maintenance requirements (see below and Section 12).
An airline can complete the entire ETOPS operational approval process
before it takes delivery of its first new ETOPS jetliner, so this airplane’s
first revenue flight can be ETOPS up to 180 minutes. This early-start
approval method is called accelerated ETOPS (see Section 1).
Early ETOPS is by far the preferred way by which the world’s airlines get
their ETOPS operational approvals. Whereas the initial required investment
is significant, introducing subsequent ETOPS airplane models to service is
far simpler and less costly.
February 15, 2008
ETOPS Explained
13–7
13. ETOPS Economics (Continued)
Flight
operations
ETOPS “flight ops” costs are generally minimal and occur in five areas:
„ ETOPS flight crew and dispatcher training.
„ Performance data generation.
„ Monitoring the ongoing availability of ETOPS alternate airports.
„ ETOPS critical fuel supply computation.
„ ETOPS-specific minimum equipment list (MEL).
ETOPS flight crew and dispatcher training—for pilots, ETOPS requires
ground training but not flight training because no ETOPS-unique piloting
skills exist that must be taught. Nevertheless, operators typically include
ETOPS-related scenarios in their regularly scheduled simulator training
(see Section 11). ETOPS training is also required for flight dispatchers.
Performance data generation—the cost of adding an airplane performance
database to support ETOPS flight planning to the airline’s standard airplane
performance database may be negligible. Boeing provides its airline customers with ETOPS flight-ops performance data and software tools.
Monitoring the ongoing availability of ETOPS alternate airports—in the
planning stage before an ETOPS route is approved, the operator identifies
ETOPS alternate airports on which its extended operations on that route will
rely. Before an ETOPS flight may dispatch, the airline must determine
whether these ETOPS alternate airports are then above the required weather
minimums and look to remain available if needed as the flight progresses.
At the start of the ETOPS phase of flight, the flight crew must again verify
the alternate airports’ continuing availability. The cost to airlines of this
safety-enhancing ETOPS alternate-airport planning is generally negligible
because weather is routinely reported by most alternates. Note that carriers
will incur additional cost on those extremely rare occasions when, owing to
the unavailability of one or more alternate airports, the ETOPS flight either
cannot dispatch or must follow a less direct flight routing.
ETOPS critical fuel supply computation—ETOPS defines the amount of
reserve fuel that must be carried to protect the airplane and its occupants
through a worst-case diversion at low altitude, either to an alternate airport
or to the destination, following a loss of cabin pressure with or without an
associated engine failure (whichever would require more fuel is assumed).
Airline ETOPS flight planning takes this critical fuel supply computation
into account. For ETOPS beyond 180 minutes, they must also take into
account the flight’s forecast winds.
Chart and flight-plan providers like Boeing business unit Jeppesen offer
en route critical fuel supply analysis and other vended services to airlines.
These initial and ongoing flight-plan services, including those that factor in
winds, add very little cost relative to non-ETOPS flight operations.
(continued)
February 15, 2008
ETOPS Explained
13–8
13. ETOPS Economics (Continued)
Flight
operations
(cont’d)
ETOPS-specific MEL—an airplane’s minimum equipment list describes
whether airplane equipment being inoperative allows, limits, or precludes
flight dispatch. Although twinjets that fly ETOPS have a modified MEL,
Boeing data analysis shows ETOPS MEL restrictions have no meaningful
impact on the rate of flight schedule disruptions. Thus, ETOPS MELs are
not a contributor of additional cost to operators (see also Section 12).
ETOPS
maintenance
An ETOPS continuous airworthiness maintenance program (CAMP) is
required for ETOPS twins but not for tris or quads when they fly ETOPS.
As the FAA itself explains in the preamble to its ETOPS rule of 2007:
The FAA strongly believes that all operators would benefit from an
ETOPS maintenance program. However, the FAA agrees with many of
the commenters that the cost of implementing this new requirement for
airplanes with more than two engines would be significant. The FAA
has determined that this cost cannot be justified based on the current
level of safety achieved by the combination of engine reliability and the
engine redundancy of this fleet of airplanes. 1
Therefore, even though Boeing and some operators share the FAA’s belief
that all ETOPS operators would benefit from an ETOPS CAMP, the 2007
ETOPS rule nevertheless allows operators of jetliners with more than two
engines to decide whether to implement one or not (see Sections 2 and 12).
ETOPS CAMP requirements minimize airplane systems failures through
disciplined maintenance procedures such as engine condition monitoring,
oil consumption monitoring, additional training to teach technicians how
to spot incipient problems, the aggressive resolution of identified reliability
issues, and procedures to avoid human error during scheduled maintenance.
For example, ETOPS requirements prohibit a maintenance technician from
working on the same engine or ETOPS significant system on both sides
of the twinjet during one maintenance session. This prohibition prevents
a maintenance error from affecting both engines or two redundant systems.
In general, ETOPS operators do not find ETOPS maintenance onerous or
burdensome. One reason is that a good airplane maintenance program will
already incorporate many of the elements in a CAMP.
Data analysis confirms that CAMP practices effectively reduce costs and
simplify operations for ETOPS twinjet operators by reducing the rate at
which engine in-flight shutdowns and other potentially disruptive system
failures occur. As a result, it is not uncommon to find airlines applying
these beneficial ETOPS maintenance practices to their non-ETOPS fleets on
a voluntary basis even though it is not required of them.
1
U.S. Federal Register, Washington, DC, vol. 72, no. 9, January 16, 2007, p. 1836.
February 15, 2008
ETOPS Explained
13–9
13. ETOPS Economics (Continued)
ETOPS
maintenance
data tracking
Over and above these direct maintenance tasks, ETOPS reduces airplanerelated diversions through the tracking and analysis of operator-reported
ETOPS maintenance data. Propulsion failures and other reliability-related
events during ETOPS flights are analyzed to identify their root causes and
determine whether or not the single event marks an emerging reliabilitycompromising trend that the industry should address. The visibility thus
provided across the world ETOPS fleet is an enormously powerful tool that
allows concerted, effective action to be taken that may ultimately make all
commercial flying safer and more reliable.
Five ETOPS
maintenance
cost areas
ETOPS maintenance costs occur in five areas:
„ Maintenance training.
„ Pre-departure check.
„ Engine and APU monitoring.
„ Reliability program.
„ Limiting work on left- and right-side ETOPS significant systems.
Maintenance training—maintenance technicians and other maintenance
personnel receive instruction on the history and philosophy of ETOPS.
This understanding quickly gains converts, who see the value of ETOPS
in preventing service interruptions and reducing unscheduled maintenance.
In general, this preventive training saves airlines money by helping ensure
that potential problems are addressed before they become a costly event for
the operator, such as an engine in-flight shutdown, diversion, air turnback,
or unscheduled engine removal (see Section 12).
Pre-departure check—the daily and pre-departure checks that all airlines
routinely perform are slightly modified for ETOPS operations (see Section
12). In conjunction with a proper scheduled-maintenance program and an
ETOPS-specific MEL, these revised checks help ensure ETOPS reliability
at little added cost.
Engine and APU monitoring—ETOPS operators closely monitor engine
parameters to detect engine deterioration sooner and more effectively. As
a result, they can take corrective action before normal airplane operation is
affected. Engine and APU oil level monitoring and consumption rates are
also tracked to help identify early problems or system deterioration. This
condition monitoring more than pays for itself by helping to reduce costly
in-flight shutdowns. As a result, some operators have also implemented
these ETOPS “best practices” across their non-ETOPS fleets.
Reliability program—this required program is event oriented in that each
ETOPS significant maintenance event (failure, removal, or write-up) is
(continued)
February 15, 2008
ETOPS Explained
13–10
13. ETOPS Economics (Continued)
Five areas
of ETOPS
maintenance
costs (cont’d)
investigated to determine its cause; corrective action is taken; and the fix is
verified to ensure the root cause has been properly identified and corrected.
An event-oriented reliability program is notably superior to a rate-oriented
program because it does not wait for a threshold rate to be exceeded before
action is taken. This component of ETOPS maintenance requirements
„ Effectively reduces airplane maintenance and operating costs.
„ Further ensures the availability of flight-critical airplane systems
and components on routes with the potential for an extendedduration diversion to an en route alternate airport.
Limiting work on left- and right-side ETOPS significant systems—this
prohibition (see page 13-9 and Section 12) precludes the possibility that a
mistake will be repeated on multiple key systems before an ETOPS flight.
The only significant potential cost to operators of this ETOPS maintenance
requirement is the possible need for a verification flight before ETOPS
service in those instances when multiple similar-systems work by a single
technician cannot be avoided.
An investment
rather than
a cost….
As the above suggests, regardless of distances flown or how many engines
the airplanes in a given fleet may have, ETOPS maintenance practices can
preclude costly service disruptions. Because these industry “best practices”
yield significant economic returns for operators, many airlines tend to view
ETOPS maintenance as an investment rather than a cost.
Spares
provisioning
The effect of ETOPS on airline spares provisioning varies from carrier to
carrier according to route structure, type of operations flown, and specific
airline policies. Since reliability is built into ETOPS twinjets, airlines do
not report a significant increase in spares investment burdens as a result of
ETOPS. Moreover, many special-equipment requirements associated with
long-range overwater operations are not unique to ETOPS, for example
special navigation and communications equipment. Consequently, threeand four-engine operators flying overwater routes have similar provisioning
requirements and investment levels as ETOPS twinjet operators.
Boeing provides ETOPS operators with a recommended spare parts list
(RSPL) based on the ETOPS fleet’s master minimum equipment list
(MMEL). Airlines may adjust the Boeing RSPL to reflect their actual
experience with component reliability, out-station provisioning needs,
diversion times of ETOPS routes they fly, and other operational factors.
The ETOPS reliability program described on the previous page allows air
carriers make informed decisions based on ETOPS maintenance program
requirements and in-service experience. As a result, some airlines use it as
a tool to help them fine-tune their ETOPS spares provisioning levels.
February 15, 2008
ETOPS Explained
13–11
13. ETOPS Economics (Continued)
ETOPS sets
the standard
for safe, reliable
long-haul flying
Flown since 1985, ETOPS ranks among the very safest and most reliable of
all flight operations, and is the state of the art in long-haul air travel. As of
December 2006, airlines had performed about 5.5 million ETOPS flights.
As airline range has increased, so too has the number of flight operations
that traverse remote areas of the world where airplanes are at times far from
an airport. Regardless of how many engines they have, all jets flying these
extended-diversion-time air routes share a common operating environment.
Thus, they all contend with similar operating challenges in terms of terrain,
weather, and limitations in navigation and communications infrastructure.
By the 1990s, awareness had arisen within the global aviation community
that the ETOPS regulatory framework—which then applied just to twinjet
extended operations—could also further protect and enhance the extended
operation of three- and four-engine airplanes. Consequently, work began
on many fronts to apply ETOPS-pioneered “best practices” more broadly
in order to lift the global industry to a higher and more uniform standard.
The first of these collaborative global efforts to reach fruition was a comprehensive regulatory updating of ETOPS by the U.S. FAA in 2007.
The U.S. ETOPS
rule of 2007
Enacted by the FAA on February 15, 2007, the U.S. ETOPS rule of 2007
„ Implements requirements updated according to the analysis of data
compiled during more than two decades of enormously successful
ETOPS twinjet operations worldwide.
„ Provides for beyond-180-minute ETOPS diversion authority while
ensuring that existing safety levels are preserved.
„ Applies selected ETOPS requirements more broadly to further
protect the operation of three- and four-engine passenger jetliners
on routes with the potential for an extended-duration diversion.
„ Allows compliant operators of approved long-range jet transports
to fly optimal routings between virtually any two cities on earth for
which their twins, tris, or quads have sufficient range.
See Section 2 for a full review of the U.S. ETOPS rule of 2007.
The 2007
ETOPS rule’s
cost impact on
twin operators
The ETOPS rule of 2007 has an insignificant impact on the cost of existing
ETOPS twinjet operations. Requirements remain essentially unchanged for
these operations at 180 minutes and below, as well for 207-minute ETOPS.
However, based on the analysis of facts and data gathered over more than
two decades of enormously successful ETOPS, the FAA has relaxed some
of the conservatism inherent in the ETOPS fuel-reserve calculations. This
reduced reserve requirement should come as welcome news to operators.
(continued)
February 15, 2008
ETOPS Explained
13–12
13. ETOPS Economics (Continued)
The 2007
ETOPS rule’s
cost impact on
twin operators
(cont’d)
As described above, the ETOPS rule of 2007 introduces a framework for
ETOPS beyond 180 minutes, setting the stage for operators to apply the
leading efficiency and reliability of long-haul twinjets on optimal routings
between virtually any two cities on earth. The result is a spectrum of new
service and revenue opportunities for carriers who fly ETOPS twinjets.
ETOPS twinjet operators will incur slightly higher ETOPS costs when they
fly ETOPS beyond 180 minutes. This increased burden, which is dwarfed
by the potential economic benefits described above, is the result of higher
propulsion reliability and operating standards than for ETOPS at or below
180 minutes. See Section 2 for an in-depth description of the ETOPS rule
of 2007 and its specific requirements.
The 2007
ETOPS rule’s
cost impact
on tri and quad
operators
The 2007 ETOPS rule will not add significant cost to three- and four-engine
passenger jetliner extended operations because only a small percentage
of these flights will ever find themselves more than three hours from an
airport. Unlike twinjets, which are subject to ETOPS once they fly beyond
60 minutes of an airport, the threshold at which tris and quads are subject
to ETOPS requirements is 180 minutes.
For operators who do fly three- or four-engine passenger jetliners beyond
three hours of an airport, the economic impact of the ETOPS rule remains
small and yields the important benefit of closing an existing gap in safety.
The rule requires tri and quad extended-diversion-time operators to perform
alternate-airport planning, create passenger recovery plans for the alternate
airports on which their ETOPS operations rely, carry a decompression fuel
reserve, and have upgraded cargo fire suppression systems.
These proven ETOPS operational requirements—which also apply to twins
when they fly beyond-180-minute ETOPS—enhance safety on challenging
routes by applying the ETOPS program’s preclude and protect philosophy,
which (1) reduces the overall rate at which airplanes divert, and (2) further
protects the airplane, its crew, and its passengers when diversions do occur.
Further reducing the cost burden on affected tri and quad passenger jetliner
operators, the 2007 ETOPS rule exempts them from ETOPS maintenance
requirements. As for tri and quad all-cargo (i.e., freighter) operators, they
are entirely exempted from ETOPS.
Conclusions
ETOPS is best described as a disciplined investment yielding significant
economic rewards. For obvious reasons, however, it is extremely difficult
if not impossible to assign a monetary value to avoided service disruptions.
Moreover, specific economic benefits will vary from one airline to another
(continued)
February 15, 2008
ETOPS Explained
13–13
13. ETOPS Economics (Continued)
Conclusions
(cont’d)
according to individual route structure, operating environment, fleet type,
accounting methodologies, and internal policies.
Although the economic benefits of ETOPS defy quantification, the global
success of ETOPS itself confirms that it provides net positive economic
value to operators. ETOPS is ultimately a cost-saving program that
„ Makes available to airlines the leading fuel efficiency, economy,
reliability, and safety of twinjets on long-haul routes.
„ Lets operators provide greater frequency of service through the use of
smaller capacity twinjets, which enhances airline revenues through:
„ More travel choices and greater convenience in travel times.
„ More of the direct nonstop flights that passengers strongly prefer.
„ Lets operators pioneer new markets, including services to secondary
population centers with insufficient aggregate travel demand to be
profitably served by large four-engine jetliners.
„ Increases market flexibility by giving airlines more ways to exploit
new service opportunities.
„ Reduces economic risk through greater ability to flexibly adapt to
seasonal and other changes in travel demand.
The U.S. ETOPS rule of 2007 provides for ETOPS beyond 180 minutes,
potentially setting the stage for compliant operators to fly their approved
ETOPS airplanes between virtually any two cities on earth for which they
have sufficient range. For twinjet operators, requirements remain largely
unchanged for ETOPS below 180 minutes, although a slight reduction in
the specified ETOPS fuel reserve will save them money. While additional
requirements apply for ETOPS beyond 180 minutes, the slight increase in
cost burden is more than offset by the enhanced revenue opportunities.
ETOPS will add very little cost to existing operations with three- and fourengine passenger jetliners (tri and quad freighter operations are exempted
from ETOPS). Most passenger jetliners will never find themselves more
than three hours from an airport, the threshold at which ETOPS applies to
tris and quads. Even on those challenging long-haul routes where ETOPS
does apply, the cost to tri and quad operators will be relatively minor and
is more than offset by the fact that ETOPS closes an existing gap in safety.
Further reducing the burden of ETOPS for tri and quad extended operators,
the ETOPS rule of 2007 exempts these operators from ETOPS maintenance
requirements.
February 15, 2008
ETOPS Explained
13–14
Most Long-Range Flying Today is by Twinjet
Total Flights Over 3,000 nmi (~8 hrs) from August Official Airline Guide each year
Twin Total
10,000
737
757
767
777
A300
A310
A320
A330
Tri Total
Quad Total
DC10
L1011
MD11
707
DC8
Twins
747
A340
8,000
6,000
4,000
2,000
Tri's
Figure 13-1
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1987
1986
0
1985
(from
August
OAG
each year)
Quads
1984
Scheduled
flights
per
week
Twinjets are Best at Holding to Schedule
Boeing and Airbus 2006 rates, airplane related technical causes only
100%
Twins
Quads
98%
97%
Percentage of flights without
a delay or cancellation
747-400
A340
97%
747-400
A340
98%
99%
737NG
757*
767*
777
A320 Series
A310*
A300*
A330
99%
Schedule Reliability
737NG
757*
767*
777
A320 Series
A310*
A300*
A330
100%
Dispatch Reliability
Twins
Quads
Percentage of flights without a delay,
cancellation, air turnback or diversion
Air Turnback & Diversion Rates
0.4
0.2
0.0
Twins Hold to Schedule 2006.cvn
747-400
A340
0.6
737NG
757*
767*
777
A320 Series
A310*
A300*
A330
Air
Turnbacks
&
Diversions
per 1,000
revenue
flights
Twins
Quads
Figure 13-2
Except for twins
entering service
prior to 1983 (*),
quads have the
highest air
turnback and
diversion rates
Twinjets Are Inherently More Fuel Efficient
The Airbus A330-300 vs. A340-300 Provides a Good Example
$20
$18
$1.2 million
per year (7%)
$17.97
$16
$16.76
$14
Cost of fuel
per year
U.S. $
(millions)
$12
A jetliner with two engines uses about
7% less fuel than one with four engines.
The airplanes in this comparison:
• Are same generation (designed at the
same time by the same manufacturer)
• Carry the same number of passengers
in the same size fuselage.
$10
• Are evaluated over the same distance.
$8
If fuel cost rises from $2.13 to $3.00 per
gallon, this twin saves $1.7 million per
year in fuel.
$6
$4
Comparison assumptions
$2
$0
A330-300
two engines
A340-300
four engines
Figure 13-3
Mission Length: 3000 NM
Annual Utilization: 640 Trips
Fuel Price: $2.13/USG
344 Seats/Dual Class (30/314)
Over 95% of Deliveries Are Twins
Boeing and Airbus 2006 deliveries
800
700
717 (5)
A300 (9)
767 (12)
794 Twins
A330 Family
(62)
777 Family
(65)
600
Commercial
Jet deliveries
in 2006 by
Airbus
and
Boeing
500
A320 Family
(339)
400
300
200
737 Family
(302)
100
38 Quads
A340 Family (24)
0
Deliveries - Twins 95% in 2006.cvn
Twins
Quads
Figure 13-4
747 (14)
Section 14
Additional Boeing and Engine
Manufacturer Services
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This section of the informational ETOPS Explained document
„
Provides a brief overview of the full-spectrum of ETOPS support that
is available from Boeing and the manufacturers of engines that power
Boeing ETOPS twinjets.
„
Explains that as the ETOPS program has broadened beyond twinjets
to also embrace three- and four-engine extended operations, so too
have the support services described below.
Note that this section, like all sections of ETOPS Explained, is formatted as
a stand-alone document for ease of use. Each section addresses a different
aspect of ETOPS. See the Introduction for a brief overview of ETOPS, key
definitions, and this BCA informational publication’s full table of contents.
Overview
Boeing and other manufacturers do an enormous amount to help operators
implement safe, reliable ETOPS programs. The intent of this collective
manufacturer support is to make ETOPS simple and seamless from the
operators’ perspective. Boeing full-spectrum ETOPS assistance includes
„ Flight operations support.
„ Maintenance support.
„ Assistance to the operator’s local aviation authority for establishment
and/or maintenance of the operator’s ETOPS operational approval.
Boeing
ETOPS flightops support
Boeing ETOPS flight operations support can include the following:
Briefings and orientation—Boeing
„ Explains the requirements for an ETOPS flight operations program.
„ Advises the airline about the ETOPS approval application process.
ETOPS program development and review—Boeing
„ Provides documentation templates and guidance to help the airline
establish its ETOPS operational and training program (including
accelerated ETOPS.)
„ Reviews the airline’s planned ETOPS flight operations program
before the application is submitted to the aviation authority.
(continued)
February 15, 2008
ETOPS Explained
14–1
14. Additional Boeing and Engine Manufacturer Services (Continued)
Boeing
ETOPS flightops support
(cont’d)
„
„
Can provide the airline’s flight operations personnel with ETOPS
training if so desired.
Will help the airline demonstrate to its aviation authority that all
required ETOPS processes are in place in the ETOPS program
that it has defined.
ETOPS program evaluation—on request or following one year of ETOPS
flying by the airline, Boeing
„ Can evaluate the operator’s existing ETOPS flight operations
program to assess its effectiveness.
„ Will offer additional assistance where desired or necessary.
Boeing ETOPS
maintenance
support
Similarly, Boeing ETOPS maintenance support can include the following:
Briefings and orientation—Boeing
„ Explains the requirements for an ETOPS Continuous Airworthiness
Maintenance Program (CAMP).
„ Advises the airline about the ETOPS approval application process.
ETOPS program development and review—Boeing
„ Provides documentation templates and guidance to help the airline
establish its ETOPS maintenance and training program.
„ Reviews the airline’s planned ETOPS maintenance program before
the application is submitted to the aviation authority.
„ Can also provide ETOPS training to airline maintenance personnel.
„ Provides guidance on the development of the airline’s Accelerated
ETOPS approval plan.
„ Will help the airline demonstrate to its aviation authority that all
required ETOPS processes are in place in its ETOPS program.
ETOPS program evaluation—on request or after one year of ETOPS
flying by the airline, Boeing
„ Can evaluate the operator’s existing ETOPS maintenance program
to assess its effectiveness.
„ Will offer additional assistance where desired or necessary.
Boeing support
to aviation
authorities
February 15, 2008
At the request of the airline undertaking ETOPS, Boeing will provide the
local aviation authority with any required assistance. Boeing can also help
the airline work with its authority to achieve ETOPS approval. In general,
Boeing seeks to keep aviation authorities apprised of the latest changes in
„ International aviation regulations.
„ Methods for evaluating airlines’ ETOPS operational
applications and procedures.
ETOPS Explained
14–2
14. Additional Boeing and Engine Manufacturer Services (Continued)
AOG assistance
Airplane-on-ground (AOG) situations are very rare events that are certainly
not a feature of ETOPS. Nevertheless, ETOPS operators know that Boeing
and engine manufacturers provide full AOG support should they ever have
a Boeing airplane stranded by damage. All Boeing customers—including
Boeing ETOPS operators—benefit from this industry-leading commitment
to rapid, effective AOG repairs.
While diversions during the ETOPS portion of flight are extremely rare,
and post-diversion AOG situations are rarer still, they can and do happen.
Air France’s 777 ETOPS diversion of July 1998 provides a good example
of the quality of Boeing support during such situations (see Section 10).
Engine
manufacturer
ETOPS support
The manufacturers of the engines that power ETOPS twinjets provide
comprehensive ETOPS support of their own. Their support includes
„ Enhancing the reliability and robustness of propulsion-related
systems (engines, accessories, and components).
„ Gathering data from the operational use of their products in
ETOPS and other service.
„ Analyzing this data and applying the lessons learned to make
tomorrow’s engines even more reliable than today’s.
„ Providing AOG engine support to help get stranded airplanes
back into revenue service as quickly as possible.
While this Boeing document cannot speak to other manufacturers’ specific
service offerings, the Air France 777 diversion described in Section 10 of
ETOPS Explained clearly demonstrates that General Electric, like Boeing,
is totally committed to providing rapid, effective AOG support.
The U.S. ETOPS
rule of 2007
On February 15, 2007, the U.S. Federal Aviation Administration (FAA)
enacted a comprehensive regulatory updating of ETOPS. Known as the
U.S. ETOPS rule of 2007, this rulemaking
„ Provides for ETOPS beyond 180 minutes, letting airlines build further
on the leading safety and reliability of long-range twinjets on routes
with the potential for an extended-duration diversion.
„ Applies selected ETOPS requirements to also embrace the extended
operation of three- and four-engine passenger jetliners when flown
on routes that take them more than three hours from an airport.
„ Ensures existing safety is maintained while creating for air carriers
the opportunity to fly properly configured and approved airplanes
on optimal flight routings between virtually any two cities on earth.
See Section 2 for more information about the FAA’s 2007 ETOPS rule.
February 15, 2008
ETOPS Explained
14–3
14. Additional Boeing and Engine Manufacturer Services (Continued)
The 2007
rule’s effects on
manufacturer’s
ETOPS services
As the scope of ETOPS expands under the ETOPS rule of 2007, so too do
the services and support described in this section. They are available to all
Boeing ETOPS operators, regardless of how many engines the airplanes in
their ETOPS fleets may have.
See Section 2 for a detailed look at the ETOPS rule of 2007 and its specific
requirements. Also see Sections 3 for information about twin-engine flight
operations, Section 4 for a review of three- and four-engine operations and
how they are affected by the new rule, and Section 13 for insights about the
economics of ETOPS.
Conclusions
Boeing and the engine manufacturers provide comprehensive support to all
Boeing ETOPS operators in the areas of
„ Flight operations.
„ Maintenance.
„ Assistance with operators’ local regulatory authorities.
As ETOPS itself changes with passage by the FAA of the U.S. ETOPS rule
of 2007, so too do the additional ETOPS-related services that Boeing and
the engine manufacturers provide to Boeing ETOPS operators.
February 15, 2008
ETOPS Explained
14–4
Appendix
ETOPS Questions & Answers
ETOPS Explained, by Boeing Commercial Airplanes
Summary
This ETOPS Q&A
„ Lists and answers frequently asked questions about ETOPS.
„ Divides these ETOPS questions and answers among the following
subject categories:
1. ETOPS Overview
4. Safety and Reliability
2. ETOPS Twinjet Operations
5. ETOPS Diversions
3. The U.S. ETOPS Rule of 2007 6. ETOPS Economics
Note that this Q&A is the appendix to ETOPS Explained, an informational
white paper whose individual sections address different aspects of ETOPS.
They and this appendix are formatted as stand-alone documents for ease of
use. See the Introduction of ETOPS Explained for an overview of ETOPS,
key definitions, and this publication’s full table of contents.
ETOPS Overview
Part 1
Question
What is ETOPS?
Answer
ETOPS (extended operations) is a conservative, evolutionary program that
allows the operators of approved two-engine jetliners, or twinjets, to fly air
routes that at some point take the airplane beyond one hour’s flying time of
an alternate airport. Flown worldwide since 1985, ETOPS ranks among the
very safest and most reliable of all flight operations; it is the state-of-the-art
in long-distance air travel.
Since 1953, airliners with two engines have been restricted to routes that
remain within one hour of an airport. In 1985, ETOPS allowed compliant
operators to fly properly equipped twinjets up to 120 minutes of an airport.
In 1988, this maximum-diversion-time limit was extended to 180 minutes.
In 2000, 207-minute ETOPS became available in certain cases.
The U.S. ETOPS rule of 2007 is a regulatory updating of ETOPS that took
effect on February 15, 2007. This rule’s requirements ensure that existing
safety is maintained while setting the stage for greater diversion authority,
potentially up to the design limit of the airplane type. Under the 2007 rule,
three- and four-engine passenger jetliners are now also subject to ETOPS
when they fly air routes that take them beyond 180 minutes of an alternate
airport. In contrast, the threshold for twinjet ETOPS remains 60 minutes
as before. See Part 3 below for more about the 2007 ETOPS rule.
March 17, 2008
ETOPS Explained
Appendix–1
Appendix
ETOPS Questions & Answers (continued)
Question
Has ETOPS been a success?
Answer
Yes, ETOPS is one of aviation’s most dramatic success stories. Performed
worldwide since 1985, it ranks among the very safest and most reliable of
all flight operations. It is the state-of-the-art in long-range air travel. As
of December 2007, over 6 million ETOPS twinjet flights had been logged.
Some 149 operators log over 1,900 more each and every day.
Question
What are the benefits to airlines that operate twinjets as opposed to
jetliners with three or four engines?
Answer
In general, airlines that fly twinjets experience fewer airplane-related delays
than do competitors flying three- and four-engine jets on the same routes.
When flying the same distance and carrying an equivalent payload, twinjets
cost less to operate, consume less fuel, and are environmentally preferred
relative to three- or four-engine jets of comparable size and performance.
Question
Are there many flights over the Atlantic Ocean by twin-engine jetliners?
Answer
Yes. In fact, two-engine jetliners in 2007 accounted for more than 77
percent of all flights across the North Atlantic. While all jetliners are
enormously safe, twinjets combine the highest overall safety and reliability
with lower fuel consumption and lower environmental emissions than other
jets.
Twinjets are not just more economical than three- and four-engine jets;
they come in more sizes. The option of smaller airplanes allows airlines to
profitably link smaller cities with direct air services. As a result, you’re
far more likely today to find nonstop flights across the Atlantic than you
were 25 years ago when three- and four-engine jets predominated across
the North Atlantic.
Question
What about other extended air routes, such as across the Pacific Ocean?
Answer
The four-engine Boeing 747 still dominates in long-range, nonstop services
across the North Pacific. Nevertheless, smaller-capacity ETOPS twinjets,
like the 767 and 777, today account for nearly twice as many transpacific
flights per day as three- and four-engine jetliners combined.
The 777 was designed from the outset with the Pacific Ocean in mind. The
world’s largest twin-engine airplane, the 777 offers greater range than any
other jetliner. After the 747, in fact, the workhorse 777 carries the greatest
number of people between Asia and North America.
March 17, 2008
ETOPS Explained
Appendix–2
Appendix
Part 2
ETOPS Questions & Answers (continued)
ETOPS Twinjet Operations
Question
Do airlines have to modify their Boeing twinjets to fly ETOPS?
Answer
Whereas some earlier Boeing twinjets were not delivered ETOPS equipped,
all the twinjets that Boeing builds today are delivered “ETOPS capable.”
Making them “ETOPS ready” is generally a quick and simple matter not
involving great expense.
Question
How are twin-engine, long-haul operations different from three- and fourengine long-haul operations?
Answer
The requirements for long-haul operations are identical if the route does
not take the airplane beyond one hour’s flying time of an alternate airport.
A nonstop flight between Singapore and London provides an example of a
route with identical operational requirements for all jetliners, regardless of
how many engines they may have.
In contrast, on routes that take the airplane beyond one hour of an airport,
ETOPS comes into effect for twinjets. The operators of these twins must
meet additional maintenance and operational requirements that
„ Further enhance the reliability of operations.
„ Further protect the airplane, its passengers, and its crew in the event a
diversion is made to an en route alternate airport.
Finally, on routes that take the airplane beyond three hours of an airport,
twinjets and passenger jets with more than two engines are all subject to
ETOPS rules. See Part 3 about the U.S. ETOPS Rule of 2007, which for
the first time applies ETOPS to three- and four-engine passenger jetliners.
Question
What about flying over polar or mountainous regions in a twinjet?
Answer
Airlines currently fly Boeing 747 and 777 aircraft on routes across the North
Polar Region (i.e., north of 78 degrees north latitude). Operation of 777
twinjets in this region is performed under 180-minute ETOPS rules.
Examples of airlines currently flying these new polar routes between Asia
and North America are United Airlines (747s and 777s), Continental
Airlines (777s), American Airlines (777s), and Air China (747s).
Regulations and standards for operating over mountainous terrain require
performance margins in the event that jetliners must cruise at reduced
altitude as a result of a propulsion failure (i.e., “drift-down performance”).
The calculated drift-down performance of two- and four-engine jetliners
(continued)
March 17, 2008
ETOPS Explained
Appendix–3
Appendix
ETOPS Questions & Answers (continued)
Answer
(cont’d)
is comparable based on the U.S. Federal Aviation Administration (FAA),
European Joint Airworthiness Authorities (JAA) rules, and International
Civil Aviation Organization (ICAO) standards for route planning.
Question
How much operational experience is required at each level of ETOPS
before advancing to the next higher level?
Answer
Widely used worldwide since 1995, the Accelerated ETOPS Operational
Approval method allows airlines to fly up-to-180-minute ETOPS with no
prior experience in the specific airplane type (airplane/engine combination)
that is planned for ETOPS. In the early 1990s, regulators and the industry
realized that sound, proven processes matter more to ETOPS success than
prior experience in type. Exploiting the process-oriented nature of ETOPS,
the Accelerated ETOPS Operational Approval method instead requires air
carriers to show they have these required processes in place.
Under the U.S. ETOPS rule of 2007, a current 180-minute ETOPS operator
can use Accelerated ETOPS to obtain operational approval to fly up to 240minute ETOPS. For beyond-240-minute approvals, however, the operator
must have accumulated two years of ETOPS experience including one year
on the actual airplane type (airplane/engine combination).
Question
Are there times when ETOPS twinjets must fly indirect routings?
Answer
That was sometimes the case in the past. With passage of the 2007 rule,
however, ETOPS twinjets can today fly optimal routings between virtually
any two airports in the world for which they have sufficient range.
Part 3
The U.S. ETOPS Rule of 2007
Question
I understand that the ETOPS rule enacted by the U.S. Federal Aviation
Administration (FAA) in early 2007 updates and standardizes ETOPS
requirements. Is this correct?
Answer
Yes, the latest development in the continuing evolution of ETOPS is the
U.S. ETOPS rule of 2007, which took effect on February 15, 2007. This
FAA rulemaking provides for ETOPS beyond 180 minutes and makes the
design capabilities of the airplane type itself the basis for determining that
type’s maximum diversion-time limit. It gives the compliant operators of
approved long-range twinjets newfound flexibility to fly optimal routings
between virtually any two cities on earth. This rule also applies ETOPS
more broadly to enhance the extended operation of passenger jetliners with
three or four engines, so ETOPS doesn’t just apply to twinjets anymore.
March 17, 2008
ETOPS Explained
Appendix–4
Appendix
ETOPS Questions & Answers (continued)
Question
What does this 2007 ETOPS rule mean to 767 and 777 operators?
Answer
Under this rule, we expect the 767 to qualify for 207-minute ETOPS, which
is a 15-percent operational extension over its current 180 minutes. As for
the 777, its operators will be able to fly any route in the world for which the
airplane has sufficient range capability and cargo fire suppression capacity.
Question
What about the new Boeing 787 twinjet?
Answer
Like the 777, the new 787 twinjet is being designed for ETOPS up to 330
minutes. Under the 2007 rule, 787 Dreamliner operators will also be able
to fly any route in the world for which the ultra-efficient 787 has sufficient
range capability and cargo fire suppression system capacity.
Question
Since the 2007 ETOPS rule also embraces passenger jets with three and
four engines, how does this rule affect existing “tri and quad” operations?
Answer
Previously, the operators of three- and four-engine passenger jetliners were
permitted to fly any routes in the world regardless of how far those routes
took the airplane from an alternate airport. Under the FAA ETOPS rule of
2007, existing tri and quad operators can still go anywhere regardless of
diversion time. However, when they fly routes that take their passenger
jets beyond 180 minutes of an airport, they must now comply with updated
safety and reliability enhancements that ETOPS twinjet operators have met
since 1985. Specifically, these tri and quad ETOPS operators must
„
Identify alternate airports for the ETOPS routes they fly and verify that
these diversion airports are above specified weather minima at the time
of dispatch and again when the jet enters the ETOPS portion of flight.
„
Develop plans that ensure the well-being of passengers at diversion
airports and provide for their safe retrieval without undue delay.
„
Carry an ETOPS fuel reserve to ensure sufficient fuel in the event
of a loss of cabin pressure and subsequent diversion at low altitude
where speed is reduced and fuel consumption increases.
„
Have the most reliable voice-based communications technology, and
have another means of communication in areas where communication
is not possible using this most reliable technology.
„
Have available all airplane performance data that might be required.
„
Be able to continuously suppress a cargo fire throughout the
maximum planned diversion time for that route.
Additionally, all jets that operate in the polar regions are subject to updated
requirements implemented by the FAA at the same time as the 2007 rule.
(continued)
March 17, 2008
ETOPS Explained
Appendix–5
Appendix
ETOPS Questions & Answers (continued)
Question
What do the new rules mean to the 747?
Answer
As stated, 747 operators can still fly the same routes as before. However,
passenger versions of the 747, like all three- and four-engine passenger jets,
must now meet ETOPS requirements that make these very safe extended
operations even safer and more reliable. In contrast, three- and four-engine
freighters are exempted from ETOPS, unlike all-cargo twinjets.
The 2007 ETOPS rule grants tri and quad ETOPS operators until February
15, 2013, to bring their existing fleets into compliance with the rule’s cargo
fire suppression system requirements. This six-year compliance window
serves to mitigate operator costs by allowing cargo fire suppression system
upgrades to be performed during regularly scheduled heavy-maintenance
intervals. It also gives airplane manufacturers time to develop and certify
these upgraded systems in their existing three- and four-engine airplanes.
Question
Does the reduction in reserve fuel requirements for ETOPS twinjets mean
a reduced level of safety?
Answer
No. Under the new ETOPS rules, twinjets in extended service will remain
fully protected while carrying somewhat less reserve fuel than in the past.
ETOPS specifies a fuel reserve to ensure adequate fuel in the exceedingly
rare event of a loss of cabin pressure followed by an airplane diversion at
low altitude where fuel consumption increases. Under the rules, this fuel
reserve requirement has simply been updated based on extensive review of
data relating to the accuracy of wind forecasting and the icing scenario of
the Canadian Atlantic Storms Program (CASP II). Under the ETOPS rule
of 2007, passenger jetliners with more than two engines will be required
to carry a depressurization fuel reserve for the first time, although many tri
and quad operators already do as a matter of internal airline policy.
Question
What about other aviation regulatory authorities? Will they enact the same
or similar regulations governing extended operations as has the FAA?
Answer
Australia recently enacted a rule similar to the U.S. ETOPS rule of 2007.
Canada has enacted a similar rule for twinjets and is now working on one
for other airplanes. It is our understanding that the extended-operations
regulations currently being developed by the European Aviation Safety
Agency (EASA), New Zealand’s aviation regulatory authority, and ICAO
are also very similar to the 2007 U.S. rule.
The Boeing Company supports the harmonization of aviation standards
among regulatory authorities worldwide.
March 17, 2008
ETOPS Explained
Appendix–6
Appendix
ETOPS Questions & Answers (continued)
Question
How will the FAA’s new ETOPS rules affect the ability of airlines to obtain
ETOPS operational approvals?
Answer
There are two basic methods by which airlines may obtain approval to
perform ETOPS:
„
In-service experience.
„
Accelerated ETOPS.
When ETOPS began, in-service experience was the only method by which
airlines could obtain approval. Based on industry experience, a second
method, accelerated ETOPS, was developed that proved very effective.
Accelerated ETOPS is a process-based approach that reduces or eliminates
the need for airlines to demonstrate in-service experience before initiating
ETOPS operations. Widely used worldwide, accelerated ETOPS is today
the preferred means for obtaining ETOPS operational approvals.
The new U.S. ETOPS regulations make it easier for airlines to obtain these
approvals by clearly formalizing requirements for both of these methods.
Question
Will the new FAA ETOPS rules require airlines to make any modifications
to their existing Boeing twinjets?
Answer
In general, operators will not have to modify their existing Boeing twinjets
to fly ETOPS. The reason is that virtually all Boeing twins built today are
delivered ETOPS capable.
Part 4
Safety and Reliability
Question
Are two-engine jetliners as safe as those with three or four engines?
Answer
Absolutely. Data analysis shows that
„ All modern commercial jet transports are enormously safe as ensured
by the rigorous type certification process.
„ Twinjets as a category are at least as safe as jets with more than two
engines.
Since 1958 through 2007, the Western world’s airlines logged about 509
million jet flights. Out of this total, twinjets accounted for 352 million
flights, or 69 percent of all commercial jetliner departures. Analysis of this
vast operational experience shows that twins consistently demonstrate the
„ Lowest overall accident rate.
„ Lowest engine-related accident rate.
(continued)
March 17, 2008
ETOPS Explained
Appendix–7
Appendix
ETOPS Questions & Answers (continued)
Answer
(cont’d)
It should be noted that although twinjets consistently rank as the safest of
all jetliners, in the real world their statistical advantage is meaningless. In
fact, the possibility of any accident occurring is so enormously remote that
for all practical purposes all jetliners are equally safe.
Question
How safe are jet engines?
Answer
Today’s high-bypass-ratio fanjet engines are enormously reliable—so much
so that it’s not uncommon for airline pilots to fly an entire career without
ever experiencing an engine failure in flight!
Concern about engines failing is an understandable holdover from aviation’s
earlier days. However, modern fanjets are vastly more reliable than the
piston engines that powered airliners back in the propeller era a half-century
ago. And since the start of the jet age, this engine reliability has continued
to increase in a dramatic ongoing trend that helps make air travel by far the
safest mode of mass transportation ever devised.
Question
Are four-engine jetliners safer over long distances than two-engine jets?
Answer
The safety and reliability of twinjets are unaffected by distances flown. At
any range, modern twinjets retain leading safety. Whether your next flight
is short, medium, long or very long, you can feel confident aboard a twin!
Over 90 percent of new commercial jetliners delivered today are twinjets,
and 90 percent of commercial flights in 2006 were made by twinjets. Since
they’re the safest, most reliable, most efficient, most economical, and most
environmentally preferred airliners, it’s hardly surprising that the industry
has standardized on two engines as the preferred configuration.
Question
Even if engine failures are rare, what happens when one fails in flight?
Answer
Twinjets are designed to fly safely in the event of an engine failure at the
most challenging time, which is during takeoff when the airplane has just
attained flying speed and is at its heaviest. Exacting certification safety
standards require the engines of twinjets to be 100 percent “overpowered”
so that either engine alone can provide all needed thrust to take off and
climb out successfully if an engine fails on takeoff.
If an engine fails or is shut down by the crew during cruise, twins can fly
indefinitely on the remaining engine. Although a diversion due to engine
failure is technically an emergency, single-engine cruise itself is entirely
safe because it is a planned, designed, and certified capability of twinjets.
March 17, 2008
ETOPS Explained
Appendix–8
Appendix
ETOPS Questions & Answers (continued)
Question
What are the chances of both engines failing on a twinjet? If that happens,
it clearly cannot sustain flight.
Answer
There are two ways that both engines can fail in flight on a twinjet. One
is for related reasons, such as running out of fuel or flying into a cloud of
volcanic ash. Events like these are enormously rare and can strike any
jetliner, regardless of how many engines it has.
Of course, both of a twinjet’s engines could also fail in flight for unrelated
reasons. What is the likelihood of this happening? In fact, the probability
of two sequential, unrelated in-flight engine failures occurring is about
1x10-10 or one chance in ten billion per flight hour.
Given such a remote probability, it is not surprising that in five decades and
352 million flights, no Western-built twinjet has ever been lost as a result of
a loss of thrust in both engines due to unrelated causes. This does not mean
that it can’t happen, but past experience and ongoing improvements in the
reliability of fanjet engines suggest that it is highly unlikely.
Question
Do some parts of a flight expose travelers to more risk than others?
Answer
Yes, some parts are riskier than others—although none is anywhere near as
risky as many of the other things that people do regularly, such as traveling
by car. All commercial flights have three phases: takeoff and climb, cruise,
and approach and landing.
Looking at jetliner fatal accident rates by phase of flight, it turns out that
cruise is the safest portion of any flight. Only about 10 percent of all fatal
accidents occur during the cruise phase, which is where ETOPS is flown.
Because so few accidents occur in cruise, long flights are not significantly
riskier than short ones. Statistically speaking, taking a single long nonstop
flight is generally safer than taking multiple shorter ones because it reduces
one’s exposure to takeoffs and landings, which are the “higher risk” phases
of flight. In practice, however, commercial air travel is so enormously safe
that there’s no meaningful difference.
Question
How reliable are twinjets compared to three- and four-engine jets?
Answer
Analysis of in-service data shows that twinjets are the most reliable of all
jetliners. They are less likely to suffer an airplane-related departure delay
and they perform fewer airplane-related air turnbacks (returns to the airport
of origin) and diversions (unscheduled landings at alternate airports). As a
result, you’re a bit more likely to get where you’re going on time on a twin.
March 17, 2008
ETOPS Explained
Appendix–9
Appendix
ETOPS Questions & Answers (continued)
Question
How has ETOPS made long-range travel safer and more reliable?
Answer
The ETOPS program is based on a dual preclude and protect philosophy
that enhances safety and reliability in two ways:
„ ETOPS-related design improvements and maintenance practices
increase the reliability and robustness of airplane engines and systems,
making it less likely that a jet will need to divert from its intended
course to an unscheduled landing at an alternate airport.
„ ETOPS operational requirements introduce proactive measures that
further protect the airplane, its passengers, and its crew should a
diversion nevertheless become desirable or necessary.
This philosophy has indirectly benefited the entire airline industry, not just
ETOPS operators. All commercial flight operations today, including those
made with three- and four-engine jetliners, benefit from gains made in the
reliability and robustness of fanjet engines and systems that were initially
achieved through the ETOPS program and have subsequently been broadly
implemented by the world’s airframe and engine manufacturers.
Part 5
ETOPS Diversions
Question
When an engine fails in flight, I know twinjets have to divert to an alternate
airport. Are three- and four-engine jets also required to divert?
Answer
In the event of an in-flight engine failure, all jetliners are required to land at
the nearest suitable airport. This is not necessarily the very nearest airport,
however, because the applicable FAA regulation (14 CFR 121.565) gives
the pilot-in-command some flexibility in determining which airport is best.
This regulation also lets tris and quads continue beyond the nearest suitable
airport if the pilot-in-command determines that so doing will not diminish
the overall safety of the flight. Nevertheless, many tri and quad crews elect
to perform precautionary diversions to the nearest suitable airport based on
their discretion or the airline’s internal policies.
Question
Does a three- or four-engine airplane have more systems redundancy than
a two-engine airplane?
Answer
Redundancy is no longer necessarily related to the number of engines on an
airplane. For example, the 777 has more sources of electrical power than
the 747. What is important is that the overall probability of total loss of
each and every critical system has been assessed and determined to provide
acceptable safety for the intended mission.
(continued)
March 17, 2008
ETOPS Explained
Appendix–10
Appendix
ETOPS Questions & Answers (continued)
Answer
(cont’d)
In this age of conservative design and enormously reliable fanjet engines,
data analysis confirms that the two-engine configuration provides optimal
propulsion redundancy as well as a safe level of system redundancy. As a
category, twinjets consistently demonstrate the lowest overall accident rate
as well as the lowest engine-related accident rate.
Question
Does Boeing design its aircraft to preclude diversions?
Answer
Yes, Boeing leads the industry in spearheading ETOPS and other reliability
enhancements that have dramatically lowered the rate of airplane-related
diversions in recent decades. Attesting to the effectiveness of these efforts,
Boeing jetliners consistently demonstrate the highest reliability rates in the
industry. The Boeing Next-Generation 737 is the most reliable jetliner in
service and the Boeing 777 follows close on its heels as the most reliable
twin-aisle jetliner. Both feature dispatch reliability above 99 percent.
Question
What more can Boeing do on the design front to avoid diversions?
Answer
Boeing and the industry have been tremendously successful over the years
at reducing the rate of technical diversions (i.e., airplane-related diversions).
While efforts continue to further enhance the reliability and robustness of
jetliner systems, however, such efforts cannot entirely eliminate diversions
because the vast majority are the result of passenger illness, bad weather,
and other factors unrelated to the airplane.
Question
Should all air carriers take alternate airports into consideration when they
plan their flights, or is this something only ETOPS operators should do?
Answer
The availability of alternate en route airports enhances safety for all flights,
not just ETOPS flights. Although diversions are rare events, any airplane
(regardless of how many engines it has) might someday need to divert to
an airport other than its intended destination for reasons that can include
passenger illness, smoke in the cabin or cockpit, turbulence, adverse winds,
weather, fuel leak, cargo fire, or the failure of an engine or other significant
system. Formalizing this alternate-airport planning, and requiring operators
to verify that their planned alternates are available through weather checks
are among the ways ETOPS enhances operational safety.
Part 6
Question
March 17, 2008
ETOPS Economics
What are the economic benefits of ETOPS?
ETOPS Explained
Appendix–11
Appendix
ETOPS Questions & Answers (continued)
Answer
The key economic benefit of ETOPS is that it allows airlines to fly twinjets
in extended service. Twinjets use less fuel, cost less to fly, and are more
reliable than tris and quads. They come in more sizes, letting airlines more
closely match airplane capacity to market demand. Smaller capacity twins
can also fly point-to-point services that would be unprofitable with a 747size airplane. All of this saves airlines money and reduces economic risk.
Question
What costs are there to ETOPS (training, maintenance, spares, etc.)?
Answer
While there are minor cost elements associated with ETOPS, experience
suggests that it is ultimately a cost-saving program. Moreover, a number
of tri and quad operators over the years have implemented some ETOPS
safety and reliability enhancements on a voluntary basis. This elective
application of ETOPS “best practices” suggests that the operational and
maintenance benefits of ETOPS are recognized by the global industry at
large, and that airlines generally find ETOPS cost effective.
Flight training—regulations require some ground training for flight crews
but not flight training as no ETOPS-unique piloting skills exist that must
be taught or practiced. Nevertheless, many airlines elect to familiarize their
flight crews during recurrent simulator training with operational procedures
and ETOPS alternate airports they might someday need to use.
Maintenance—ETOPS twinjet operators must implement an ETOPS
maintenance program that
„ Dramatically reduces the rate of on-wing engine failures and other
in-flight failures of critical systems, sparing airlines many potentially
costly service disruptions.
„ Is generally characterized by ETOPS operators as being neither
burdensome nor onerous.
Spares—the ETOPS program does not specify or recommend spare parts
provisioning levels for airplanes. Spares provisioning is up to the airlines
and is not necessarily affected by whether a flight is ETOPS or not. Spares
are generally not identified by operators as a source of ETOPS-related cost.
Question
How does an ETOPS twinjet compare against a four-engine jetliner in
terms of maintenance and spares?
Answer
Twinjets require less maintenance since they have half as many engines and
fewer parts overall than four-engine airplanes. For these same reasons, the
quantity of spare parts that airlines must stock is somewhat lower for twinjet
fleets than for tri or quad fleets.
March 17, 2008
ETOPS Explained
Appendix–12