DRAFT 26Aug 2014
Navigation errors associated with pilot navigation procedures and the ARINC
424 (7.2.5) half degree waypoint naming convention
Meeting Report
12 August 2014
1.
On 12 August 2014, an online meeting was conducted to discuss the topic associated
with the North Atlantic (NAT) Implementation Management Group (IMG) Decision 44/4 - Navigation
errors associated with pilot navigation procedures and the ARINC 424 (7.2.5) half degree waypoint
naming convention. The meeting started with introductions of attendees. The participants are listed in
Attachment A.
2.
Kevin Kelley, Rapporteur for the NAT Operations and Airworthiness Subgroup,
presented the agenda and emphasized the objectives of the group (Attachment B refers). He emphasized
the NAT IMG decision and highlighted the objective of the tasking.
“NAT IMG Decision 44/4 – Navigation errors associated with pilot navigation procedures and
the ARINC 424 (7.2.5) half degree waypoint naming convention
That the United States of America:
a) coordinate with NAT CNSG, all NAT ANSPs, flight operations authorities, avionics suppliers,
operators and navigation data providers to investigate possible mitigation measures to navigation
errors associated with pilot navigation procedures and the ARINC 424 half degree waypoint naming
convention;
b) based on the outcome of a) above, develop proposals to help pilots readily distinguish half (½)
degree from whole degree of latitude waypoints entered into flight management computers and shown
on aircraft map displays for consideration by the appropriate NAT SPG Contributory Bodies, and;
c) submit an update, as appropriate, to NAT IMG/45.”
3.
3.1
Discussion.
Insights on Thirty-Three Reported Half-degree Events
a) The group was presented with a paper for discussiontitled “Human Factors Considerations for
North Atlantic and Half Degree Waypoints” from two human factors subject matter experts. The
paper is presented in Attachment C to this report. It was noted that for the types of error resulting
from the prefix/suffix confusion of ARINC 424 (7.2.5) that training as to the proper procedure for
entering and verifying the waypoints is critical. However, training alone cannot be expected to
eliminate all errors due to this cause. Also, in regards to display ambiguity, in such cases, a pilot
needs to “expand” waypoint labels on the FMS, one at a time to verify the coordinates
represented by the display label.
b) It was noted that the paper did not address the impacts that a change to an existing standard might
have on the system. Additionally, no assessment was made to address impacts based on crew
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DRAFT 26Aug 2014
training cycles. Similarly, the paper did not consider in benefits of expanded route clearances. It
was noted that these factors would have to be the subject of an expanded study if the group
decided to pursue this.
c)
3.2
The group noted that in anticipation of the RLatSM implementation, an aeronautical navigation
data base (NDBs) provider updated the 3 April navigation data bases to include 175 new ½degree latitude oceanic waypoints. This update to the NDBs was not properly coordinated with
the Operators or the Air Navigation Service Providers (ANSPs). It was noted that the
uncoordinated nature of this change to the current conduct of operations in the North Atlantic was
a factor which deserves more mention in the root cause analysis of the lateral deviations, in
particular whether awareness and/or training might have reduced or eliminated the lateral
deviations. The draft analysis should be updated to reflect these points.
Review of Possible Mitigations
a) Generally speaking it was noted that the draft list in Attachment E was a good start as some
possible mitigations. So that the group can identify those items that may be achievable in the
near term and which items would be longer term fixes, timelines need to be established for those
items that the group ultimately agrees upon. Some in the group felt entries on training on the
ARINC 424 (7.2.5) standard and manual entry of oceanic waypoints should include expanded
listings of advantages and disadvantages.
b) Route Uplinks. The group noted that once fully established, autoload of route data would be
very useful in reducing pilot waypoint insertion errors. Some of the subject matter experts noted
that work was still needed to see this item fully implemented. The list of advantages and
disadvantages for this item needed more input from the group.
c) Removing the ARINC 424 Supplement 20. Paragraph 7.2.5 half-degree waypoints.
Regarding this possible mitigation the group had good discussion. Some of the points that the
group made were;

that any changes to the current standard should be considered within a global
context;

that consideration needs to be given to the effects of all systems that would be
impacted and any consideration of change should be harmonized accordingly;

that the lateral deviation problem should be considered in light of the uncoordinated
change to the navigation data base and the scope of the issue should be considered;

that if no change to ARINC 424 is contemplated, the group should consider whether
the use of the ½-degree waypoints should be prohibited? If this were decided, what
additional safety analysis is needed for this; that impacts the use 5ANC would have
on the system and how would these be implemented should be considered; and

The group may determine that this proposed mitigation and its global nature make
this mitigation beyond the scope of the IMG decision and should be considered by
ICAO Montreal .
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d) Training and Outreach. It was noted that this would be a factor no matter what mitigations
would be recommended. IATA proposed that the group may want to review both the NAT Doc
007 and the Oceanic Bulletins to see if any improvements could be made related to the
implementation of RLatSM.
3.3
Statements
a) Jeff Miller of IATA made some remarks, and referred to an email, which is copied here:
“In the short to midterm (RLATSM Phase 1), the IATA recommendation is:
1) All NAT Region stakeholders support the use of full LAT/LONG coordinates in an ½
degree lateral airspace design,
2) work to increase the awareness of GNEs causal factors, best practices and adherence
to current procedures,
3) maximize utilization of current technology (CPDLC) to deliver oceanic clearances
and reroutes.
In the long term (RLATSM future implementation), the IATA recommendation is:
1) eliminate the “automation language” differences between FDPS and the aircraft
systems,
2) develop a regional ½ degree named WPT (“5ANC”) implementation plan that would
have global acceptability/harmonization, and
3) work toward an inclusive/collaborative process to include follow-up safety analysis
(post step #2 above), stakeholder training of the new airspace environment, and
4) due consideration is taken of associated technical processes including, aircraft and
FDPS uplink / downlink capability and limitations, FMS capability and limitations,
operator flight planning automation systems, and changes to the oceanic Track
Message, etc.”
b) Mike Hynes of IFALPA likewise made some statements and followed them up with an email,
which is pasted here: ”I’m hopeful this is supportive of the increased use of a technology
solution (increased uplinks, and better naming or truncation formats) while recognizing the
short term need to begin the trial and the longer term training, systems modification and
global approval requirements.
1) A very limited number of one-half degree waypoints have existed globally for some
time. The forthcoming wide-spread use of one-half degree waypoints will be a “new”
process for all operators, flight crew and ANSPs, resulting in the development of
modifications to various systems and a “new” training requirement for all parties.
2) Solutions must be globally adoptable, and common in all areas (i.e., the NAT
solution should not differ from a Pacific solution).
3) Expand use of Route Uplinks by ANSPs and Operators for processing enroute
ATC/ANSP clearances or clearance (track) changes, and operator requested re-routes
to eliminate a potential source of error (flight crew manual entry of waypoints).
4) Use of the full thirteen-character latitude/longitude format for one-half degree
waypoints provides a common, easily understood process for all flight crews,
operators and ATC/ANSPs.
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5) Waypoint display/naming/formatting differences (ARINC 424 naming conventions,
truncation methods, etc.) between operator flight planning systems, aircraft flight
management systems and ATC/ANSP track messages and systems should minimize
the potential for waypoint confusion (i.e., minimize human factors hazards).
6) Operator and flight crew use of Oceanic waypoint and route verification procedures
must continue to be strongly emphasized.”
4. Next Meeting. The next group meeting is scheduled for 4-5 September in Paris.
Attachments
A. List of Attendees
B. Meeting Agenda
C. Human Factors Considerations for North Atlantic and Half Degree Waypoints
D. Results of Error Analysis (DRAFT)
E. Possible Mitigation Measures (DRAFT)
\
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ATTACHMENT A – List of Attendees
John Kasten
Roy Grimes
Steve Smoot
Karen Chiodini
Kevin Kelley
Steven Pinkerton
Tom Kraft
Marvin White
David Maloy
Jerry Bordeaux
Kathy Abbott
Edward Malloy
Bob Gaul
Cameron Crow
Kelly Dillard
Ekkehard Gutt
Rich Stark
Jeff Miller
Mike Hynes
Leifur Hákonarson
Kyle Jermyn
Christian Gruetter
Noel Dwyer
Luis Tojais
Finlay Smith
Tony Summers
Tracy Lennertz
ARINC Member of ICAO IFPP
CSSI, Inc.
CSSI, Inc.
FAA
FAA
FAA
FAA
FAA
FAA
FAA
FAA
FAA Contractor
Garmin
Garmin
Garmin
IATA
IATA
IATA
IFALPA
ISAVIA
Jeppesen
Lido
NAV Canada
NAV Portugal
UK NATS
UK NATS
Volpe
A-1
John.Kasten@jeppesen.com
RGrimes@cssiinc.com
Steve.CTR.Smoot@faa.gov
Karen.l.Chiodini@faa.gov
kevin.c.kelley@faa.gov
steven.pinkerton@faa.gov
Tom.Kraft@faa.gov
marvin.e.white@faa.gov
david.maloy@faa.gov
jerry.bordeaux@faa.gov
kathy.abbott@faa.gov
edward.ctr.molloy@faa.gov
bob.gaul@garmin.com
cameron.crow@garmin.com
kelly.dillard@garmin.com
ekkehard.gutt@emirates.com
naked@mindspring.com
millerj@iata.org
mike.hynes@alpa.org
leifur.hakonarson@isavia.is
Kyle.Jermyn@jeppesen.com
christian.gruetter@lhsystems.com
Noel.Dwyer@navcanada.ca
Luis.Tojais@nav.pt
finlay.smith@nats.co.uk
tony.summers@nats.co.uk
Tracy.Lennertz@dot.gov
DRAFT 26Aug 2014
ATTACHMENT B – Agenda
Proposed agenda:
1. Welcome; Review of IMG Decision 44/4; Issues affecting pilot ability to “readily discern whole
from half degree waypoints”
2. NAT ANSP Insights on 33 Reported Half Degree Events (Gander, Reykjavik, Shanwick, Santa
Maria)
a) Presentation of root cause questionnaires, each event
b) Summary information/ additional comments
3. Human Factors Analysis of ½ Degree Environment (FAA Human Factors; Volpe Human Factors)
4. Review of Possible Solutions
a) Expand Use of CPDLC Route Uplinks
b) Remove Half Degree 424 7.2.5 Supp 20 Waypoints
c) Remove outright (status quo)
d) Publish 364 New 5-Alphanumeric Name Code Waypoints via Common-Language
Aeronautical Information Circular
e) Revise 424 7.2.5 Convention
f) Training
g) Modify Avionics
5. Face-to-Face Meeting Objectives
6. Meeting Report
7. Recommendations
8. Comments by Industry, Groups, & Regulators
B-1
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ATTACHMENT C - Human Factors Considerations for North Atlantic and Half Degree
Waypoints
Kim Cardosi, PhD
US DOT/Volpe Center
National Expert, Aviation Human Factors
Kathy H. Abbott, PhD, FRAeS
Federal Aviation Administration
Chief Scientific and Technical Scientific
Advisor, Flight Deck Human Factors
Prefix/suffix confusion: The current ARINC 424 paragraph 7.2.5 naming convention employs a single
discriminator, placement of the letter “N” as a prefix or a suffix to the four numbers which denote the
latitude and longitude, to distinguish between whole degree of latitude waypoints and half degree of
latitude waypoints. For example, “5940N” denotes N59°/W40°, whereas “N5940” denotes
N59°30’/W40°.

Training as to the proper procedure for entering and verifying the waypoints is critical. However,
such errors would be expected to continue even with significant training and checking procedures
in place for several reasons. First, it is a basic human factors principle that training is not an
effective mitigation strategy for such ‘slips.’1 Second, such errors are difficult to capture and
correct.2
Display ambiguity: Avionics that truncate or round the full coordinate values can display whole-degree
waypoints and half-degree waypoints as identical. In such cases, a pilot needs to “expand” waypoint
labels on the FMS, one at a time to verify the coordinates represented by the seven-character label.
A format less susceptible to errors should be:


compatible with CPDLC route uplinks,
easily communicated between pilots and controllers (that is, entry into the FMS should be
consistent with the way that the clearance is given).
Additionally, discrepancies between the uplinked or manually-entered route and intended route should be
easy for the pilot to identify.
Note that the material discussed above is based on HF expertise and previous operational events. Analysis
of the GNEs attributed to operations using half-degree waypoints still needs to be completed.
1
A slip is a type of error where the pilot meant to do the correct action but carried it out incorrectly.
The half-degree waypoint issues could be considered one example of a larger set of difficulties in pilot interaction
with the FMS. The larger set of issues is discussed in the Report of the PARC/CAST Flight Deck Automation Working
Group http://www.faa.gov/aircraft/air_cert/design_approvals/human_factors/media/OUFPMS_Report.pdf. See
paragraph 3.2.4.4: “The occurrence of FMS programming errors and lack of understanding about FMS operation
appear across age groups and cultures. The errors are noteworthy and it has not been possible to mitigate them
completely through training (although training could be improved). This reflects that these are complex systems
and that other mitigations are necessary.”
2
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In short, effective training and cross-checking need to be encouraged, but other measures need to be taken
to minimize the susceptibility of crew error in entering fixes where half-degree waypoints are used in the
route clearance shown on navigation displays.
C-2
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ATTACHMENT D – Results of Error Analysis (DRAFT)
An analysis of North Atlantic lateral deviation errors associated with half degree of latitude waypoints for
the period March-June 2014 was conducted to identify the root cause for these events.
Thirty-three (33) events were reviewed and analyzed to determine the probable root cause leading to the
event. It is noted that International General Aviation (IGA) business aviation aircraft having the range
capability for intercontinental flight were involved in a disproportionate number of events as 19 of the 33
occurrences are attributed to these aircraft types yet they only generate 5.2% of total NAT operations.
Two event types are evident within the data: leading/trailing character entry errors and double entry of
longitude. The distribution of the events is as follows:
Distribution of Events by Type
Leading/Trailing Character Entry Errors
<FL350
FLs 350-390
>FL 390
Waypoint Insertion Errors Due to Double Entry of
Longitude
<FL350
FLs 350-390
>FL 390
Total
Total
IGA
COM
30
4
14
12
17
2
3
12
13
2
11
-
3
-
2
1
1
1
1
33
19
14
The root cause analysis was conducted by FAA contract support personnel using the 5 Whys Technique.
This process involved stating the problem of how the recent surge in gross navigational errors (GNEs)
could adversely impact NAT risk. The Tree Diagram Tool was used to ask why the problem exists and
then show the logical relationship for each response to the preceding cause. The process was stopped
when the probable root cause was identified from the available data. It is noted that more data from the
events, such as flight crew statements, would permit a more conclusive finding. The root cause for the
recent surge in GNEs within the NAT, nonetheless, can be attributed to a recent update of ½ degree of
latitude waypoints named in the ARINC 424 paragraph 7.2.5 convention and ultimately flight crew
confusion with the trailing and leading characters when entering waypoints using latitude and longitude
coordinates. The diagram is presented below:
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ATTACHMENT E – Possible Mitigation Measures (DRAFT)
Possible Mitigations
Subject matter experts have reviewed the issues and agreed upon the following list of possible mitigations
and identified advantages and disadvantages of each.






Expand the Use of Route Uplinks
Remove ARINC 424 Supplement 20, paragraph 7.2.5 half-degree waypoints
Promulgate five-alphanumeric named waypoints via common-language AIC
Revise ARINC 424 paragraph 7.2.5 naming convention
Implement Training and outreach to be used in conjunction with other mitigations
Modify Avionics
Mitigations
Advantages
Disadvantages
Expanded Use of Route Uplinks
 Eliminates errors associated
with manual entry of FMS
waypoints
 Could be implemented without
publishing additional
waypoints
 Supports and socializes future
enhanced functionality for
enroute data comm services
 Smaller GA aircraft—which
have made most of the half
degree errors—are not likely
to equip and therefore would
not benefit from this solution
 Does not mitigate related
issue of display ambiguity,
unless 5LNC or 5ANC
waypoints are introduced and
used
Remove ARINC 424 Supplement
20, paragraph 7.2.5, half degree
waypoints
1. Remove outright (no
replacement of half degree
waypoints)
 Reduces the likelihood of
prefix/suffix confusion
(preserves “not in database”
error message)
 Can be implemented quickly,
as this is a continuation of the
status quo
E-1
 For avionics which parse the
waypoint name, errors
associated with prefix/suffix
confusion could persist,
unless the ARINC 424 7.2.5
convention is revised or
waypoints are promulgated
 Does not resolve display
ambiguity due to truncation/
rounding/ generic coding of 7character waypoint display
identifier
 Does not reduce errors
associated with manual entry
of FMS waypoints
DRAFT 22 Aug 2014
 Not fully compatible with 2
of 3 CPDLC route clearance
messages (UM79 & UM83)
 Requires adaptation of flight
planning systems
2. Promulgate fivealphanumeric name
code (5ANC)
waypoints via
common-language
AIC
 Resolves prefix/suffix
confusion
 Resolves display ambiguity
due to truncation/rounding
generic coding of 7-character
waypoint display identifiers
 Fully compatible with all 3
CPDLC route clearance
messages (UM79, UM80 &
UM83)
 Reinforces pilot-ATC
communications by creating
common frame of reference
 Requires adaptation of ground
ANSP systems and flight
planning systems
3. Revise ARINC 424
paragraph 7.2.5
naming convention
 Addresses prefix/suffix
confusion
 Resolves display ambiguity
due to truncation/rounding/
generic coding of 7-character
waypoint display identifiers
 Compatible with CPDLC
functionality
 Requires adaptation of flight
planning systems
 Not fully compatible with 2
of 3 CPDLC route clearance
messages (UM79 & UM83)
Training and Outreach to be used
in conjunction with other
mitigations
 Can address issue of crews not
following current cockpit
procedure
 Is limited in addressing
processes inherently prone to
error
Modify Avionics
 Issues could be addressed as
required
 Cost and Schedule make this
a long term solution out of the
scope of discussion
E-2