NATIONAL TRANSPORTATION SAFETY BOARD
Office of Aviation Safety
Washington, DC 20594
Operational Incident Report
March 28, 2002
OPS01SA002
A.
RUNWAY INCURSION
Location:
Denver International Airport, Colorado
Date:
September 25, 2001
Time:
0948 Coordinated Universal Time (UTC)1
Aircraft:
UPS flight 896 (UPS896), Boeing 757-200
B.
AIR TRAFFIC CONTROL and AIRPORT GROUP
Chairman:
Mr. Scott J. Dunham
National Transportation Safety Board
Washington, D.C. 20594
Mr. Michael Coulter
National Air Traffic Controllers Association
Denver, Colorado
Mr. Dan Diggins
Federal Aviation Administration
Washington, D.C.
Mr. Clayton Hewitt
Federal Aviation Administration
Washington, D.C.
Mr. Brannon Mayer
National Transportation Safety Board
Denver, Colorado
Mr. Mark Taylor
Federal Aviation Administration
Seattle, Washington
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All times are expressed in local time except “History of Flight” which is stated in UTC.
1
SUMMARY
On September 25, 2001, at about 0948 UTC, UPS896, a Boeing 757 operating under 14
Code of Federal Regulations Part 121 as a cargo flight from Denver, Colorado, to Reno,
Nevada with two crewmembers aboard, departed from runway 8 at DEN. The runway
was closed because of construction workers and equipment operating on taxiway R7.
The aircraft passed within 32 feet of a light standard erected near taxiway R7 to
illuminate the construction area. No injuries were reported on the ground or aboard the
aircraft, and the flight continued to its destination. The incident occurred in nighttime
visual meteorological conditions.
D.
DETAILS OF THE INVESTIGATION
The investigative group assembled at the Denver International Airport operations office
on October 10, 2001 to discuss airport issues reflected in this incursion with Mr. Eric
Hall, the acting Chief Aviation Operations Manager, and Mr. Mark Lovin, the Deputy
Airport Manager for Operations. I also supplied the group with copies of the preliminary
FAA incident report, airport diagrams, crew statements, statements from the construction
superintendent, and copies of relevant FAA Advisory Circulars on airport markings and
distribution of notices to airmen. On October 11, 2001, the group met at the Denver Air
Traffic Control Tower (ATCT) to review previously requested air traffic control data,
listen to position tapes, and interview the three controllers on duty during the midnight
shift of September 25. On October 12, the group met to finalize field notes and complete
the field portion of the investigation.
1.
History of Flight and Crew Statements
The crew of UPS896 first contacted Denver ATCT at 0930, requesting their IFR
clearance to Reno. The tower controller used the pre-departure clearance delivery
equipment to relay the aircraft clearance directly to the crew via a datalink receiver
aboard the aircraft. At 0940 the crew reported that they were approaching the taxiway A
hold bar and that they had ATIS arrival information “Hotel”. The tower controller
instructed UPS896 to “stand by” and gave control instructions to another aircraft
intending to land on runway 17R. After completing her exchange with the arriving
aircraft, the tower controller asked the crew of UPS896 if they would like to depart from
runway 35L at the M4 taxiway intersection, which left 8400 feet of runway remaining.
The crew responded that they could accept runway 35L. The tower controller then
instructed the crew of UPS896 to taxi northbound on taxiway M and hold short of
taxiway EA because of company traffic southbound that would be turning right at taxiway
EA. At 0941:31, the crew of UPS896 reported having the company traffic in sight and
advised that they would hold short. At 0942, the tower controller advised UPS896 that
ATIS departure information Victor was current and instructed the crew to change to
frequency 133.3. The crew acknowledged. At 0942:16, the crew of UPS896 was
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instructed to taxi to runway 35L at taxiway M4 and advise when they were ready for
departure. At 0943:57, the crew of UPS896 advised the tower controller that they would
need to use runway 8 because they did not have the necessary departure data for runway
35L. The tower controller responded, “UPS896 no problem, continue northbound to
runway 8.”
At 0947:35, the tower controller contacted the radar departure controller to coordinate an
eastbound departure for UPS896 on the Meeker transition. The tower controller advised
the departure controller that the aircraft would be leaving the airport on a 080 heading.
The departure controller responded, “oh yeah, that’s fine.” At 0947:45, the crew of
UPS896 reported ready to go at runway 8. The tower controller responded, “UPS896 fly
heading 080, wind is 210 at 12, runway 8 cleared for takeoff. Traffic at your 10:00, 12
miles company heavy Boeing 747 on a base for runway 17R.” At 0948:03, the crew of
UPS896 acknowledged, stating, “okay 896 will be looking for him and cleared to go
runway 8.” At 0950:00, the tower controller instructed the crew of UPS896 to contact
departure. The crew acknowledged. UPS896 continued to Reno, and the crew made no
comments about the proximity of the construction equipment.
At 0950:53, the tower controller was called on the ground control frequency by
Engineering 567. The tower controller misunderstood the identification and responded,
“Agent air 567 Denver ground?” Engineering 567 then transmitted, “this is tower?” The
controller responded, “This is Denver tower.” Engineering 567 then transmitted,
“engineering 567 8-26 is believed closed?” The tower controller responded, “Agent air
526 (sic) affirmative.” She then transmitted, “oh”. The controller then engaged in
communications with other aircraft on the airport. At 0951:51, Engineering 567
transmitted, “Engineering 567 why did a plane take off from 8-26?” The controller did
not respond. At 0954:34, Airport Operations 8 contacted ground control and requested
permission to drive to the east side of the airport. (Information provided during
interviews indicated that the airport operations staff was responding to the construction
site after being contacted by the construction crew about the incident.) The tower
controller responded, “Ops 8 you are approved to the east side taxiways, give way to all
traffic, remain clear of all runways.”
According to statements submitted by the captain and first officer, they decided to use
runway 8 for departure after finding that they did not have suitable takeoff data for
runway 35L, their originally cleared runway. They requested the change and were cleared
by the tower controller to taxi to runway 8. After moving into takeoff position on the
runway, both pilots noticed the lights around the construction area downfield. However,
the activity all appeared to be clear of the side of the runway, so they decided to take off.
According to their statements, the aircraft passed through a cloud of dust near the
construction site, but the pilots were unaware that they had departed from a closed
runway until the next day when notified of the reported incident by UPS flight operations.
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2.
Personnel Interviews
Mark Lovin
City and County of Denver Airport Management
Eric B. Hall
Mr. Hall and Mr. Lovin are employed by the City and County of Denver (CCD) and are
responsible for operational management of the Denver International Airport. Mr. Lovin
is the Deputy Manager for Airport Operations, and Mr. Hall works for him as the acting
Chief Airport Operations Manager. Mr. Hall supervises 12 airport operations managers
and 20 to 25 assistant airport operations managers. These individuals are directly
responsible for airport compliance with all Part 139 airport certification requirements, and
provide oversight of airport operations 24 hours a day. They are responsible for
monitoring activities such as construction projects and handling any other operational
issues that arise on a day-to-day basis.
If runway closures are necessary, the operations managers are responsible for
coordination with air traffic control via telephone or radio to ensure that the tower is
aware of the closure. When on-field construction occurs, the operations manager is
responsible for ensuring that the construction site is set up and marked properly.
Communications are maintained between the contractor and the airport operations
manager with radios and cellphones. The specifications for work to be performed are
provided by the airport engineering department and supervised by an airport engineering
foreman. While there is no airport requirement that an airport employee be on duty with
the contractor team at all times, when this incursion occurred the work was being
monitored by Mr. Francisco Montejano on behalf of CCD. (Following the incident, Mr.
Montejano filed a written report with airport operations. This report is included in the
docket information.)
The contractor was replacing a concrete joint on taxiway R7, which is located about 3500
feet east of the approach end of runway 8. While the worksite was on the taxiway, the
construction crew was operating within the runway safety zone and sweeper equipment
was occasionally entering the runway itself to turn around and reenter the taxiway. The
contractor had been told by CCD staff to remain clear of the runway to the maximum
extent possible. The R7 taxiway ends were blocked by portable flashing red lights.
Based on information received from the operations manager on duty, Mr. Hall is satisfied
that the contractor was operating within the constraints imposed by CCD on the work
site.
Airport operations staff have access to a Systems Atlanta Information Display System-4
(IDS4) data communications and retrieval computer. This is part of a system that is
maintained by Denver Terminal Radar Approach Control to promote information
exchange between Denver area airport and air traffic control facilities. The IDS4 is used
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to transmit NOTAM information to Denver AFSS for distribution on behalf of the
airport. On the evening of September 24, the airport communications log showed that a
NOTAM had been sent to Denver AFSS stating that runway 8-26 would be closed
overnight. However, later investigation by the airport operations office revealed that
there was a failure in the IDS network that may have lasted as long as nine hours and
prevented the NOTAM from being transmitted to the AFSS. As a result, the NOTAM for
the closure of runway 8-26 was never distributed to the public. Mr. Hall stated that the
procedure for NOTAM issuance is that the information is entered in IDS4 and generally
acknowledged by the AFSS specialist receiving the data. If the acknowledgement is not
received within 30 minutes of transmission, the airport communications specialist is
supposed to telephone the AFSS to confirm receipt. This confirmation call was not
made, so the airport communications staff did not know that the NOTAM was effectively
lost. There is no established process for ensuring that the IDS4 system is fully
operational and that the messages are going through: the only backup is the phone call
made if the AFSS does not send an acknowledgement message.
When asked about the minimum required markings for a closed runway, Mr. Lovin
responded “Nothing.” There are no regulatory requirements for marking temporarily
closed runways.
Since the incident, Mr. Lovin stated that CCD has begun obstructing the runway
entrances closest to the thresholds of a closed runway with cones or an airport vehicle,
and also activating the in-pavement stop bars at those intersections. (Note: According to
subsequent observation by the tower controllers, this procedure is not consistently
applied.) They have elected not to use the stop bars at all intersections because it may be
necessary for vehicles to cross the stop bars during their construction work, and the
airport does not want to teach drivers that it is ever acceptable to cross a lit stop bar.
Airport operations managers have been verbally instructed to have the runway lights shut
off unless the nature of the work being performed requires that they be on. (Note: Tower
controllers report that this procedure is not consistently applied.) Normal practice is to
also ask the tower to confirm that the approach lights are off as well. Specific procedures
for closures are left to the discretion of the airport operations manager involved because
of the variety of possible situations they encounter. He stated that the airport depends on
controllers to do their jobs properly and control access to the airport movement areas. Air
traffic procedures must be reliable and compensate for the possibility of human error.
Mr. Lovin believes that the FAA’s efforts in research and development of airport surface
technology are inadequate and fail to keep up with the needs of airport operators. He also
expressed serious concerns about the FAA Notice to Airmen system, stating that it was
badly in need of replacement with a more modern system that better meets the needs of
users. Mr. Lovin agreed to supply NTSB with background information on previous
exchanges with FAA on airport marking issues.
5
Lora Jackson
Denver ATCT LC2
Ms. Jackson began working for the FAA at Stapleton Airport, Denver, Colorado, on
January 7, 1992. She completed training at Stapleton on September 5, 1993, and
transferred to Denver International Airport in February 1995 when the airport opened.
She has a control tower operator certificate, and her current medical certification expires
August 31, 2002, with no limitations or waivers. Ms. Jackson provided the following
answers in response to questions.
On the night of the incident involving UPS896, Ms. Jackson was assigned a 2300-0700 L
shift. Earlier that day, she had worked a 0530-1330 shift, went home, and in the
intervening period got 60 to 90 minutes sleep before returning to work. The night before
her 0530L shift, she reported going to bed at 2000 or 2100 and waking up at about 0345L.
She reported no unusual life events, personal problems, or other issues that might have
affected her performance. Ms. Jackson’s self-assessment was that she was feeling “pretty
good” at the time of the incident.
Ms. Jackson arrived at work at about 2230, in accordance with local policies that allow
controllers to begin work up to 30 minutes in advance of their scheduled shift time. She
was not originally assigned to be controller-in-charge for the shift, but agreed to take that
responsibility after a request from Kimberlynn Cannioto, the originally assigned CIC.
Consequently, Ms. Jackson spent the initial part of the shift performing administrative
duties: completing logs from the previous day, transferring carry-over items to the next
day’s log, confirming equipment status with the maintenance control center, etc. During
this period, Ms. Cannioto left the cab, and Craig Sullivan was working all control
positions combined. Ms. Jackson completed the administrative duties at about 0100. Ms.
Cannioto returned to the cab, received a position relief briefing from Mr. Sullivan, and
took over the control positions. Ms. Jackson and Mr. Sullivan then left the cab on a
break. Ms. Jackson returned at approximately 0300, received a position relief briefing
from Ms. Cannioto, and began working aircraft. Ms. Cannioto remained in the cab
engaging in conversation with Ms. Jackson until about 0325. She then left the area,
leaving Ms. Jackson as the only controller in the tower cab. Mr. Sullivan was still absent.
There were “a couple” of inbound aircraft in the vicinity of the airport. UPS896 called
for IFR clearance to Reno, and Ms. Jackson used the tower’s pre-departure clearance
system to transmit the clearance. A few minutes later, UPS896 requested taxi
instructions, and was cleared to runway 35L at intersection M4 for departure. When the
aircraft reached that point, the pilot advised that they would need runway 8 for departure.
Ms. Jackson responded by clearing the aircraft to runway 8. She then contacted Denver
TRACON to coordinate the aircraft’s departure heading. Following that coordination,
Ms. Jackson cleared UPS896 to take off on runway 8.
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Less than a minute later, Ms. Jackson received a radio call from what proved to be the
construction crew working next to runway 8, inquiring about whether runway 8 was
closed. She looked at the placard in the strip bay showing that runway 8 was closed, and
advised the construction crew accordingly. She then realized what had happened.
The placard and aircraft flight strips were all located in the strip bay above the ASDE
display at LC2. Ms. Jackson believes that she may have moved the UPS896 strip to the
countertop when the pilot requested the runway change, but she is not sure. The Runway
Incursion Device (RID) was active and audible, and her relief briefing included
information on the runway closure and the location of the construction equipment. Ms.
Jackson stated that she may have been engaged in non-work-related writing at the time of
the incident. She believes that UPS896 was between taxiway EE and the runway 8
threshold when cleared for takeoff. Ms. Jackson said that she didn’t remember if she
scanned the runway before issuing clearance, but she knows that she is supposed to do so.
Airport operations called on the telephone right after the incident and informed Ms.
Jackson that everyone was all right in the work area, but they wanted to make sure that
this (aircraft departure on runway 8) was not going to happen again. They also made the
initial report that the aircraft had missed construction lighting equipment by about three
feet. Airport operations vehicles went to taxiway R7 after the phone call, and the
construction work was terminated shortly afterward.
Ms. Jackson called Ms. Cannioto to the cab immediately after completing the call with
operations. Ms. Cannioto took over the control positions and also assisted Ms. Jackson in
completing the required paperwork and notifications. A few minutes later, Mr. Sullivan
returned to the cab.
When asked what she thought caused this error, Ms. Jackson replied that she was,
“…probably tired, not alert enough.” She believes that she was following the procedures
she was supposed to follow. In the future, she may make an entry on the ARTS
DBRITEdisplay to note that the runway is closed. She did not use such a memory aid on
the night of the incident, but she knows how to do so. She also thinks that cones or other
markings and shutting the runway lights off might also help to prevent a recurrence.
When asked about having more than one controller in the cab, she agreed that perhaps
another person might have caught her mistake. Ms. Jackson has no other explanation for
the error.
Ms. Jackson does not recall looking at the ASDE radar display while handling UPS896,
but she had seen the construction equipment on the ASDE earlier in the shift. She did
look at the runway after the incident, and noted that while sitting at the LC2 position a
structural roof support blocked her line of sight to the construction area. By shifting her
position a little, the construction lighting and equipment was readily visible.
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Runway 8 is the preferred departure runway on midnight shifts because of noise
abatement concerns. All departures from runways 8 and 35L are turned to a 080 heading
after takeoff.
Ms. Jackson stated that the normal means of communication with airport construction
personnel is via radio to the airport operations personnel. Construction workers are
normally escorted to their worksite by airport operations staff and then left to do their
work. If the controllers need to contact them, airport operations is contacted and asked to
go to the construction site to pass the message. Ms. Jackson noted that the construction
crew contacted her via radio after the incident, but she was not previously aware that the
crew had a radio. When work is completed, the airport operations people notify the tower
to reopen the runway or taxiway and then escort the construction crews off the airport
movement area. Relief briefings normally include information on any operations vehicles
in the airport movement areas.
When runways are closed, control of the lighting system can be passed to maintenance
personnel or retained in the tower, in accordance with instructions from airport
operations. Ms. Jackson does not recall the control status of the lights for runway 8.
Craig Sullivan
DEN ATCT
EOD FAA 1987
Cheyenne, Wyoming ATCT 1987 - 1996
DEN ATCT since 1996
Completed training at DEN ATCT 1997
Mr. Sullivan was interviewed at Denver ATCT on October 11, 2001, and provided the
following information in response to questions.
In the days leading up to this incident, Mr. Sullivan reported that his work schedule
included the following shifts
Friday, 1500-2300; Saturday, 1300-2100; Sunday, 0700-1500; Monday, 0600-1400;
Tuesday, 2300-0700
Mr. Sullivan tries to get at least three hours of sleep before working a midnight shift, and
stated that he actually got about three to three and a half hours sleep on the evening
before this shift. On Sunday night, he went to bed at about 2200. Mr. Sullivan got up at
0330 Monday morning and left home at 0430 in order to be on time for his 0530-1330
shift.
On the evening of the incident, Mr. Sullivan arrived at work at 2230. He worked all the
control positions in the cab combined until 0100. At that point he was relieved from
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position and told by the CIC (Lora Jackson) that he need not return until 0445, when he
would be expected to work the clearance delivery position. At 0100, Mr. Sullivan went
downstairs to the 2nd floor lunchroom. He spent his entire break in the lunchroom, and
stated that he was awake throughout, reading, watching a movie and television. Persons
in the 2nd floor lunchroom can be contacted by either telephone or the internal building
paging system. When asked if it was normal for a controller assigned to a three-person
midnight shift to disappear from the cab for half of the shift, Mr. Sullivan stated that
before the incident it was allowable but that the policy changed on September 25th.
Before this incident, there was normally only one person in the cab from 0100-0400.
Three people is normal midshift staffing, but it was usual to send someone off on a break
from 0100 to 0445 or so, returning because the cargo rush starts about then. When asked
why the facility staffs three persons on midnight shifts, Mr. Sulivan said, "I assume it is
for position relief, breaks, and sick leave. Two is absolutely bare minimums." He works
midnight shifts as often as possible.
Three to four controllers usually come to work at 0530 and take over the entire operation
from the midnight shift. On 9/25 enough people came in at 0530 to relieve all the
midnight shift controllers, so their work on control positions was done.
Runway closures are typically verbally coordinated between airport operations and the
OS/CIC. When controllers are notified that a runway is closed, a “Runway Closed”
placard is placed in the local controller’s strip bay, the runway incursion device is
activated, and appropriate entries are made in the facility operations log. At night, the
runway lights are turned off if requested by airport management. The tower may give
control of runway lights to maintenance if they ask for it. If lighting status was not
discussed, Mr. Sullivan stated that he would leave the lights alone (on). He also stated
that he is not aware of any specific provisions in the 7110.65 addressing lighting status on
closed runways. Mr. Sullivan does not recall if lighting status was discussed during his
oncoming position relief briefing. He was briefed that runway 8 was closed, but didn't
question the status of the lighting system. When asked if he could see the construction
equipment while working at the LC2 position, Mr. Sullivan said, “Yes.”
When he was relieved from the control positions at 0100 by Kimberlynn Cannioto, Mr.
Sullivan briefed her about the runway closure and recalled at least one discussion about
the taxiway construction. He stated that the construction work was perfectly visible from
the tower, but it was hard to tell whether they were on the runway or off. On the ASDE
display, the construction looked half-on and half-off the runway."
Mr. Sullivan first learned of the incursion incident at 0445 when he returned to the tower
cab. No one called him before that time. Kim was working and Lora was making phone
notifications. Mr. Sullivan started working CD, and was later briefed on what had
happened. When asked why he wasn't called earlier, Craig said that he was frustrated that
they hadn't called, but Kim and Lora had told him that they just didn't think of it. When
Mr. Sullivan returned to the cab, Lora was visibly upset and acknowledged that she had
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"messed-up". Kim’s demeanor appeared normal.
Mr. Sullivan stated that it is not unusual for pilots to request runway 8 for departure even
when the ATIS says it is closed. Runway 8 is the preferred noise abatement runway for
midnight shift departures. Mr. Sullivan did not have occasion to communicate with the
construction personnel while working his control position. If he needed to do so, he said
that he would contact OPS7/8 and have them contact the construction crew. OPS does
not always stay with construction crews while they are working on the airport.
When asked if he had any suggestions to help prevent a reoccurrence of this incident, Ms.
Sullivan stated that facility management has now mandated two persons on position
during the entire midnight shift. He has worked a midnight shift under the new rules and
liked the change; the extra eyes/ears are a good thing, and the policy benefits the
operation. Mr. Sullivan thinks that controllers have, “…plenty of memory tools available
- it's whether we choose to pay attention to them. Anyone can have a mental lapse.”
Mr. Sullivan noted that the ATIS is often cluttered with taxiway closures, which results in
runway closures not standing out. He believes that ATIS announcements should be less
cluttered with data so that the important items are more obvious.
Kimberlynn Cannioto
Denver ATCT
Ms. Cannioto entered on duty with the FAA in November, 1991, and began working at
Denver Stapleton airport in April, 1992. She remained there until Stapleton closed, and
then moved to Denver International airport. She completed certification in February,
1995. She has a valid control tower operator certificate and medical certificate.
In the days leading up to the incident, Ms. Cannioto reported working Friday, 1500-2300;
Saturday, 1400-2200; Sunday, normally 0700-1500, but was on sick leave; Monday,
0600-1400, but was on antibiotics and worked clearance delivery all day due to doctor's
orders; and Tuesday, 2300-0700. Tuesday was a normal work day, but she was still
feeling ill at times. She spent most of Sunday resting, and made two doctor visits on
Saturday and Sunday. She went to bed at 2000 on Sunday night and awoke at 0400
Monday morning. Ms. Cannioto stated that she usually tries to get three to three and a
half hours sleep before midnight shifts and did so on Monday night. She did not report
having any personal problems that would interfere with her work.
Ms. Cannioto stated that the position sign-on logs are accurate in accounting for her time
on the shift. She arrived at work at 2230, stayed in the cab for a few minutes, left the cab
at about 2250, and returned at 0100. She worked all the control positions combined from
0100-0300, was relieved by Lora at 0300 and stayed to talk to her until 0325. Lora
appeared to be alert during that conversation.
Upon leaving the cab, Ms. Cannioto went to the junction-level breakroom and put
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hotpacks on her eyes. She stated that she had been diagnosed with a viral infection in her
eyes that did not affect her vision, but needed treatment. A short time later, Lora phoned
Ms. Cannioto in the break room, stated "I need you", and then hung up. Ms. Cannioto
returned to the cab immediately. Lora was visibly upset, and said that she had departed
an aircraft on a closed runway. Ms. Cannioto took over the control positions, put the
frequencies on the speaker, and started the notification paperwork. She and Lora both
made the required phone calls. After doing this for a few minutes, traffic started to
require Ms. Cannioto’s full attention so she stopped assisting Lora. Although she was
aware that Mr. Sullivan was in the second floor break room, she didn’t think about calling
him back to the cab. Ms. Cannioto continued to work traffic until about 0530 when she
was relieved by a day shift controller. She continued to act as CIC until about 0600.
After relinquishing the CIC responsibilities, Ms. Cannioto reviewed the position voice
tapes with Lora and left for home after 0630.
Ms. Cannioto recalled that during the 0100 relief briefing with Mr. Sullivan the RID was
on, the “Runway 8/26 Closed” placard was up, and the lighting control panel indicated
that runway 8 was closed. Sitting at the LC2 position, taxiway R7 was very clearly
visible, but the view could be obstructed by roof support posts from some locations in the
tower cab. Ms. Cannioto did not recall whether the runway 8/26 lights were under
control of the tower or had been released to the airport management.
Generally, when airport operations plans to close runway they provide advance
notification to the tower; when the closure actually begins, the operations manager calls
on ground frequency to close the runway and gets an acknowledgement.
Although Ms. Cannioto was not aware of the requirement at the time of the incident, she
knows now that 7110.65 requires lights to be turned off on closed runways. Ms.
Cannioto’s past practice was that if OPS asked to close a runway without requesting that
the lights be shut off, she assumed that they needed the lights on and left them that way.
She stated that she reads “a few pages” of the 7110.65 several times a month for refresher
training.
When asked about past practice in staffing midnight shifts, Ms. Canniotto said that
normally two people worked 2230-0100 and 0400 to end of shift. Day shifters usually
come in at 0530 and relieve the midnight shift controllers.
Ms. Cannioto was originally scheduled to act as CIC for the shift. Ms. Cannioto asked
Lora to take that responsibility instead because she was not feeling well, and the
arrangement was approved by the evening shift supervisor, who then gave Lora the CIC
relief briefing before going off duty.
Ms. Cannioto remembered discussing the taxiway R7 closure with Lora. The airport
operations manager had told Ms. Cannioto that R7 had a hole in the surface and would be
closed until about Thursday. Taxiway R7 had not previously been reported closed on the
ATIS, so she included the information on the next ATIS broadcast. The 0300 position
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relief briefing with Lora included information on the runway 8 closure, the fact that
taxiway R7 had a hole in it and was closed, and traffic operating in the vicinity of the
airport.
When asked for recommendations on ways to minimize the chance of reoccurrence of an
incident such as this, Ms. Cannioto suggested that entrances to closed runways should be
coned off. She also thought that adding a “Runway Closed” data tag to the DBRITE
could be useful, and thought that having two people on control positions during midnight
shifts is a good idea.
FAA Directives and Guidance on Surface Operations and Markings
Air Traffic Control Directives
FAA order 7110.65, “Air Traffic Control,” paragraph 3-4-9, Runway Edge Lights, states
in part:
Operate the runway edge light system/s serving the runway/s in use as
follows:
a. Between sunset and sunrise, turn the lights on:
1. For departures - Before an aircraft taxies onto the runway
and until it leaves the Class B, Class C, or Class D surface area.
2. For arrivals:
(a) IFR aircraft - Before the aircraft begins final
approach, or
(b) VFR aircraft - Before the aircraft enters the
Class B, Class C, or Class D surface area, and
(c) Until the aircraft has taxied off the landing
runway.
b. Between sunrise and sunset, turn the lights on as shown in
subparagraphs a1 and a2 when the surface visibility is less than 2 miles.
c. As required by facility directives to meet local conditions.
d. Different from subparagraphs a, b, or c above, when:
1. You consider it necessary, or
2. Requested by a pilot and no other known aircraft will be
adversely affected.
e. Do not turn on the runway edge lights when a NOTAM closing
the runway is in effect.
NOTE Application concerns use for takeoffs/landings/approaches and does not
preclude turning lights on for use of unaffected portions of a runway for
taxiing aircraft, surface vehicles, maintenance, repair, etc.
Although the NOTAM implementing the closure apparently was not issued because of
administrative difficulties between the airport management office and Denver AFSS, the
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runway edge lights should have been turned off based on the requirements of this
paragraph and the information provided directly to the tower controllers by airport
operations staff.
FAA order 7110.65, paragraph 3-3-2, Closed/Unsafe Runway Information, states in part:
If an aircraft requests to takeoff, land, or touch-and-go on a closed or
unsafe runway, inform the pilot the runway is closed or unsafe, and
a. If the pilot persists in his/her request, quote him/her the
appropriate parts of the NOTAM applying to the runway and inform
him/her that a clearance cannot be issued.
b. Then, if the pilot insists and in your opinion the intended
operation would not adversely affect other traffic, inform him/her that the
operation will be at his/her own risk.
PHRASEOLOGY RUNWAY (runway number) CLOSED/UNSAFE.
If appropriate,
(quote NOTAM information), UNABLE TO ISSUE
DEPARTURE/LANDING/TOUCH-AND-GO CLEARANCE.
DEPARTURE/LANDING/TOUCH-AND-GO WILL BE AT YOUR
OWN RISK.
Although the closure information was available on the ATIS, this paragraph requires a
direct response when a pilot requests landing or departure on a closed runway. The local
controller apparently did not realize that runway 8 was closed, and therefore did not
inform the pilot of UPS896 that the runway was closed when the pilot asked to use the
runway.
FAA order 7110.65, paragraph 3-3-3, Timely Information, further states in part:
3-3-3 Timely Information
Issue airport condition information necessary for an aircraft's safe
operation in time for it to be useful to the pilot. Include the following, as
appropriate:
a. Construction work on or immediately adjacent to the movement
area.
When the crew of UPS896 reported having ATIS information Hotel, which was the
arrival ATIS, the local controller informed them that information Victor (the departure
information) was current. She did not subsequently verify that they had actually received
information Victor or directly inform them of the construction activity. Both ATIS
broadcasts stated that runway 8 was closed. Controllers are not required to include the
13
reason for closures in ATIS broadcasts, so the crew would not have had any specific
information on the type of activity being conducted near the runway.
Advisory Circulars
FAA advisory circulars AC150/5200-28B, “Notices to Airmen (NOTAMs) for Airport
Operators”, AC150/5370-2C, “Operational Safety on Airports During Construction”, and
AC150/5340-1H, “Standards for Airport Markings”, all contain provisions relevant to
this incursion.
Advisory circular AC150/5200-28B states, ”The management of a civil airport which is
open for public use is expected to make known as soon as practical (but normally not
more than 3 days before the expected condition is to occur) any condition on or in the
vicinity of the airport, existing or anticipated, which would prevent, restrict, or present a
hazard to arriving or departing aircraft.3 Public notification is normally accomplished by
the NOTAM system. This same notification coverage should be made when the condition
has been corrected or otherwise changed … In addition, in the case of airports certificated
under 14 CFR Part 139, airport operators have certain requirements set by regulation for
dissemination of information concerning conditions on and in the vicinity of their airports
that may affect the safe operation of aircraft. Detailed information is contained in 14
CFR Part 139 and the individual Airport Certification Manual/Specifications.”
14 CFR 139.339, Airport Condition Reporting,” states:
(a) Each certificate holder shall provide for the collection and
dissemination of airport condition information to air carriers.
(b) In complying with paragraph (a) of this section, the certificate holder
shall utilize the NOTAM system and, as appropriate, other systems and
procedures acceptable to the Administrator.
(c) In complying with paragraph (a) of this section, the certificate holder
shall provide information on the following airport conditions which may
affect the safe operations of air carriers:
(1) Construction or maintenance activity on movement areas, safety areas,
or loading ramps and parking areas.
According to AC150//5370-2C, the airport operator is responsible for establishing and
using procedures for the immediate notification of airport users and the FAA of any
conditions adversely affecting operational safety at the airport. This is normally
accomplished through the NOTAM system. Section 10 of the advisory circular addresses
marking and lighting of closed or hazardous areas on airports, and section 10(b) provides
specific guidance about temporarily closed runways and taxiways. For temporary
closures, the FAA states that the airport operator “should” place crosses over the runway
numerals, and hazardous construction areas should be marked with flags, barricades, and
flashing yellow lights. Advisory circulars do not have regulatory effect, so such markings
are not mandatory: a closed runway need not be marked at all.
14
AC150/5340-1H addresses the marking of temporarily closed runways in more detail.
Paragraph 41 of this advisory circular states:
41. TEMPORARILY CLOSED RUNWAYS AND TAXIWAYS. The
following procedures are to be followed when it is necessary to
temporarily close a runway or a taxiway:
a. When it is necessary to provide a visual indication that a runway is
temporarily closed, X's are placed only at each end of the runway on top of
the runway designation markings or just off the runway end when required
by construction activity. The X's are yellow in color and conform to the
dimensions specified in Figure 20. Since the X's are temporary, they are
usually made of some easily removable material, such as plywood or
fabric rather than painted on the pavement surface. Any materials used for
temporary X's should provide a solid appearance. Since these X's will
usually be placed over white runway markings, their visibility can be
enhanced by a 6 (15 cm) black border.
b. A raised-lighted X may be placed on each runway end in lieu of the
markings described in paragraph 41a to indicate the runway is closed. The
X is to be located within 250 feet (75 m) of the runway end. Normally the
raised-lighted X would be located on the runway; however, it may be
located in the safety area on the extended runway centerline.
c. Temporarily closed taxiways are usually treated as hazardous areas (see
paragraph 48). However, as an alternative, a yellow X conforming to the
dimensions in Figure 20 may be installed at each entrance to the taxiway.
d. If the runway or taxiway will be closed during the nighttime, the runway
and taxiway lights will normally be disconnected so that they can not be
illuminated unless such illumination is needed to perform maintenance
operations on or adjacent to the runway, e.g., snow removal.
15
OPS01SA002 - Attachment to Factual Report
DEN ATCT operational error 9/25/01 0948 UTC
NTSB transcript of relevant communications between Denver tower LC2, UPS896, and
others on September 25, 2001, 0930-0955 UTC.
0930:32 UPS896
Denver clearance UPS896 to Reno
0930:54 UPS896
Denver clearance UPS896
0930:56 LC2
UPS896 just Denver uh clearance I just sent that over the PDC do
you want to get that from there?
0931:01 UPS896
OK
0931:03 UPS896
there it came thanks
0935:47 UPS586
[unintelligible] 586 with you on a visual runway uh 17 right
0935:52 LC2
UPS596 Denver tower wind is 200 at 13 last 3000 feet of the
runway is closed runway 17 right cleared to land.
0936:00 UPS596
cleared to land 17 right UPS596 thank you
0940:21 UPS896
Denver ground UPS896 we’re approaching the alpha hold bar we
have uh hotel
0940:29 LC2
UPS896 stand by. UPS596 turn right either high-speed then turn
right on echo alpha southbound on lima to sierra charlie
0940:42 UPS596
UPS596 all right we’ll take a right at uh echo charlie
0940:49 LC2
UPS596 did you copy? [unintelligible] right behind you taxi
southbound on mike then right at echo alpha then southbound on
lima to sierra charlie.
0940:58 UPS596
echo alpha to lima sierra charlie did you say UPS596?
0941:02 LC2
UPS596 affirmative.
0941:15 LC2
UPS896 would you like runway 35 left mike 4, 8400 feet
remaining?
16
0941:20 UPS896
yes ma’am we can do that
0941:23 LC2
UPS896 taxi northbound on mike and hold short of echo alpha
there will be company southbound turning right at echo alpha
0941:31 UPS896
OK we have the company in sight and will hold short for him
UPS896
0942:00 LC2
UPS896 information victor is current, change to my frequency
133.3.
0942:06 UPS896
896
0942:16 LC2
UPS896 company no longer a factor taxi runway 35 left mike 4
and advise when you’re ready.
0942:22 UPS896
896 will do
0942:59 LC2
UPS896 you can taxi min delay traffic’s on a downwind for a
company heavy DC8 for runway 17 right. I need to get you out of
here a little quickly.
0943:54 UPS896
tower UPS896
0943:55 LC2
UPS896 tower you ready to go?
0943:57 UPS896
ah we’re going to need runway 8 ma’am. We don’t have the data
for this runway.
0944:01 LC2
UPS896 no problem continue northbound to runway eight.
0944:04 UPS896
all right sorry about that.
0944:06 LC2
no problem.
0947:03 UPS806
tower UPS806 heavy uh right base 17 right.
0947:09 LC2
UPS806 heavy Denver tower wind is 210 at 12 runway 17 right
cleared to land last 3000 feet of the runway is closed.
0947:17 UPS806
cleared to land 17 right UPS806 heavy.
0947:35 LC2
DR local?
0947:36 DR
[unintelligible]
17
0947:37 LC2
I see you coming in from the east there. I do have one to depart
runway 8 he is a Meeker transition
0947:41 DR
OK
0947:42 LC2
umm to do you want me I’ll send him out on an 80 [unintelligible]
up
0947:45 DR
oh yeah that’s fine bz
0947:45 UPS896
UPS896 ready to go runway 8.
0947:48 LC2
UPS896 fly heading 080 wind is 210 at 12 runway 8 cleared for
takeoff traffic at your 10:00 12 miles company heavy Boeing 747
on a base for runway 17 right.
0948:03 UPS896
ok 896 will be looking for him and cleared to go runway 8.
0949:40 UPS802
tower UPS802 left base to 17 right
0949:44 LC2
UPS802 heavy Denver tower caution wake turbulence heavy DC8
on a mile and a half final wind is 200 at 13 last 3000 feet of the
runway is closed runway 17 right cleared to land.
0949:56 UPS802
cleared to land UPS802.
0950: 00 LC2
UPS896 contact departure
0950:03 UPS896
896 good day
0950:53 ENG567
ground control engineering 567
0950:59 LC2
agent air 567 Denver ground?
0951:04 ENG567
this is tower?
0951:07 LC2
this is Denver tower
0951:11 ENG567
engineering 567 uh 8-26 is believed closed?
0951:16 LC2
agent air 526 affirmative
0951:18 LC2
oh
18
0951:51 ENG567
tower engineering 567 why did a plane takeoff from 8-26?
0954:34 Ops8
ground ops 8 approaching two echo for the east side will give way
and remain clear.
0954:40 LC2
ops 8 you are approved on the east side taxiways give way to all
traffic remain clear of all runways.
End of transcript.
19
NATIONAL TRANSPORTATION SAFETY BOARD
Office of Aviation Safety
Washington, D.C. 20594
December 17, 2001
Human Performance
Specialist's Review Report2
AS50/RR-02/01
Topic area:
The Effects of Work Schedule, Fatigue, and Vigilance
On Air Traffic Controller Performance
Prepared By:
Bartholomew Elias, Ph.D.
Senior Human Performance Investigator
National Transportation Safety Board
Office of Aviation Safety
Human Performance Division (AS-50)
Washington, DC 20594
In support of:
Runway Incursion
UPS Flight 896, Boeing 757
Denver International Airport
September 25, 2001
OPS01SA002
2
Note: This review provides a synopsis of scientific research and other background information
relevant to selected human performance issues. It does not provide analysis of the facts and
circumstances of any accident or incident currently under investigation.
20
The Effects of Work Schedule, Fatigue, and Vigilance
On Air Traffic Controller Performance
Safety Board staff reviewed scientific research addressing work schedule,
fatigue, and vigilance on air traffic controller (ATC) alertness and performance.
1. Work Schedule
Rotating shift schedules can often result in an accumulation of sleep debt
producing chronic fatigue by interfering with normal circadian patterns and
exposing workers to rapid changes in work-rest cycles that they are unable to
adequately adapt to. Counterclockwise rotating schedules (i.e., schedules
requiring the worker to report for duty at an earlier time than previously worked)
are particularly problematic because they oppose normal sleep-wake patterns
that tend to be on a cycle slightly greater than 24-hours which is more amenable
to slow forward shift rotations.3 Counterclockwise rotation also can produce an
accumulation of sleep debt over the course of a duty rotation due to the reduced
time off between sequential shifts.
In the United States, work-rest schedules for ATCs are comprised of 8hour shifts (limited to a maximum of 10 hours with overtime) with a minimum of
eight hours off duty between shifts. Over the course of a shift, ATCs are allotted
one cumulative hour for breaks and the maximum time on position between
breaks is limited to two hours.4 A commonly used Federal Aviation
Administration (FAA) ATC schedule involves working two eight hour evening
shifts, then rotating to two eight hour day shifts followed by a single eight hour
night shift. Shift intervals are often rotated counterclockwise within this schedule,
resulting in a compressed work week often referred to as a 2-2-1
counterclockwise rotation. For example, an ATC may work the following typical
duty rotation5:
Day 1: 1600-0000
Day 2: 1400-2200
Day 3: 0800-1600
Day 4: 0600-1400
0 Day 5:
0000-0800
3
Tepas, D. I. & Monk, T. H. (1987). Work schedules. In G. Salvendy (Ed.), Handbook of Human
Factors. New York, NY: John Wiley and Sons.
4 Wickens, C. D., Mavor, A. S., & McGee, J. P. (Eds.) (1997). Flight to the Future: Human Factors
in Air Traffic Control. Washington, DC: National Academy Press.
5 Luna, T. D. (1997). Air Traffic Controller Shiftwork: What are the Implications for Aviation
Safety? A Review. Aviation, Space, and Environmental Medicine, 68(1), 69-79.
21
While this 2-2-1 shift rotation provides for longer off-duty periods following
a weekly duty cycle, it significantly reduces off duty periods during the work week
potentially impacting sleep. Research has generally shown that sleep quantity,
sleep quality, and self reports of sleepiness do not differ significantly between
ATCs on 2-2-1 shift schedules and those on other shift schedules during the first
four days of a duty cycle.6 However, some research has shown that while ATCs
on 2-2-1 shifts schedules got more sleep than ATCs working straight night shifts,
they got less sleep than ATCs working straight day shifts.7
While research has not conclusively established that ATCs experience
cumulative sleep debt over the course of a 2-2-1 shift schedule, research has
clearly demonstrated that ATCs working 2-2-1 shifts get significantly less sleep
preceding the night shift at the end of their duty rotation. In studies, ATCs have
generally reported mean sleep duration between 2.5 and 3.75 hours prior to the
night shift.8 However, research using objective sleep measures, such as
measurements from wrist worn actimeters and electroencephalograms (EEGs),
indicates that actual sleep periods are about one hour less than these self
reported sleep durations.9 Therefore, research has demonstrated that ATCs
working 2-2-1 shifts are typically getting only a few hours sleep before reporting
for the night shift at the end of their duty rotation.
2. Fatigue
Research has shown that various work related factors affect an
individual's level of fatigue including:







Time since awakening;
Time on duty;
Time on task;
Physical and mental workload demands of the job;
Reduced rest and recovery times between shifts;
Environmental factors such as noise and lighting; and
Time of day.10
6
See Marcil, I. & Vincent, A. (2000). Fatigue in Air Traffic Controllers: Literature Review.
Transport Canada Publication Number. TP 13457. Montreal, Quebec: Transport Canada
Transportation Development Centre.
7 Marcil, I. & Vincent, A. (2000).
8 Luna, T. D. (1997).
9 Luna, T. D. (1997).
10 See Battelle Memorial Institute (1998, January). An Overview of the Scientific Literature
Concerning Fatigue, Sleep and the Circadian Cycle. Prepared for the Office of the Chief Scientific
and Technical Advisor for Human Factors, Federal Aviation
Administration; Marcil, I. & Vincent, A. (2000). Fatigue in Air Traffic Controllers: Literature
Review. Transport Canada Publication Number. TP 13457. Montreal, Quebec: Transport
Canada Transportation Development Centre.
22
With regard to time of day factors, research has shown that subjective
reports of alertness closely correlate to body temperature, which is important in
regulating daily sleep-wake cycles. Both body temperature and alertness are
lowest during the early morning hours. Research has demonstrated that
performance among shift workers on a low memory load task closely matches
circadian variation of body temperature and alertness and is poorest during the
early morning hours. However, performance on a high memory load task
showed an opposite effect with improved performance among shift workers
during the late evening and early morning hours.11 This suggests that low
workload tasks requiring sustained vigilance, as opposed to complex focused
tasks, are particularly prone to performance degradation due to fatigue and
decreased alertness. ATCs working night shifts requiring sustained vigilance
during periods of low traffic load may be particularly susceptible to fatigue effects
due to low workload, low ambient lighting, and the circadian trough in alertness
that occurs during early morning hours. The effects of fatigue during night shifts
may be further influenced by reduced off duty periods and lack of adequate
sleep prior to reporting for the night shift.
Research has also shown that individuals suffering from fatigue exhibit
increased task fixation resulting in an inability to shift quickly from one subtask to
another and an inability to divide attention to auxiliary tasks. 12 Also, intermittent
lapses in consciousness, referred to as microsleeps, have been shown to
degrade performance among fatigued individuals by leading to errors of omission
due to missed information. These microsleep episodes can also potentially lead
to a loss of situational awareness and errors of commission if they become
frequent enough or long enough.13
3. Vigilance
In general, research has demonstrated that performance decreases and
errors increase with increasing time on task. Factors such as fatigue and
boredom tend to amplify these vigilance decrements. Performance decrements
and decreased alertness associated with time on task are even more
pronounced if the operator is suffering from sleep loss or sleep disruption. 14
Research has shown that detection efficiency, the ability to make timely
responses without sacrificing accuracy, declines significantly with increasing time
on task during afternoon and evening hours but not in the morning. 15 This is
consistent with research indicating relatively high rates of operational errors
among ATCs at moderate and low task load periods occurring during late night
and early morning hours.16
11
Tepas, D. I. & Monk, T. H. (1987).
Battelle Memorial Institute (1998, January).
13 Battelle Memorial Institute (1998, January).
14 Marcil, I. & Vincent, A. (2000).
15 Craig, A., Davies, D. R., and Matthews, G. (1987).
16
Wickens, C. D., Mavor, A. S., & McGee, J. P. (Eds.) (1997).
12
23
Research has demonstrated that vigilance decrements in highly practiced
tasks are more pronounced when the task elements are varied as compared to
tasks involving highly automatized and consistent responses.17 Thus, operators
are more likely to make errors as their shift proceeds when faced with variations
from normal operations. Research has also shown that a shift in operator criteria
on vigilance tasks occurs as the day progresses. Specifically, during the
afternoon and evening hours, operators tend to adopt more liberal judgment
criteria resulting in greater detection rates accompanied by increased false alarm
rates. 18 This is consistent with evidence from fatigue research indicating that
individuals experiencing fatigue are satisfied with lower performance and allow
perceived errors to go uncorrected. Thus, evidence from research examining
fatigue and vigilance indicate that judgment and decision-making are impaired by
fatigue and sustained time on task.
In summary, performance deficiencies on vigilance tasks are likely to be
manifest in response to novel, non-routine events and involve the use of more
liberal judgment and decision-making criteria thus increasing the probability of an
error of commission. The combined effects of low event rates and irregular
traffic flow during late night and early morning periods make ATCs particularly
prone to vigilance related performance effects during these times. 19 A decrease
in alertness due to fatigue and circadian (time of day) factors during these
periods may interact with sustained vigilance and time on task factors to increase
the likelihood of an operational error.
Submitted By:
Bartholomew Elias, Ph.D.
Senior Human Performance Investigator
17
Fisk, A. D. & Scerbo, M. W. (1987). Automatic and control processing approach to interpreting
vigilance performance: A review and reevaluation. Human Factors, 29(6), 653-660.
18 Craig, A., Davies, D. R., and Matthews, G. (1987). Diurnal variation, task characteristics, and
vigilance performance. Human Factors, 29(6), 675-684.
19 Marcil, I. & Vincent, A. (2000).
24