Page 8 - Interpilot Issue 1 2016
P. 8

Update from North Atlantic

the FMC LEGS page. ADS conformance on the “half degree” Oceanic track. During the
Capt. Mike hynes (RVP NAT)
monitoring identifies this error to ATC. A trial period, inflight routing onto the “half
ncreased equipage number of aircraft types (examples from B767 degree” Oceanic track should not be accepted
Iwith Automatic and B777 fleets were noted) suggest flight unless the route can be uplinked to the FMC
Dependent Surveillance crews to NOT enter SLOP immediately prior, (i.e., avoid inflight manual entry of
(ADS) and Controller or within close proximity, to a waypoint (not thirteen-character half degree latitude and
Pilot Data Link within 4 NM suggested). Flight crews should longitude waypoints). More information can
C o mm unic a t io n s review FM procedures or bulletins to be alert be found in ICAO NAT OPS BULLETIN
(CPDLC) for flights to this hazard. 2015_03 – RLatSM Special Emphasis Items
within North Atlantic effective 1 June 2015.
(NAT) airspace NAT Reduced LATeRAL SepARATioN
continues to reduce the MiNiMA (RLATSM) TRiAL AuToMATed RouTe coNfoRMANce
number of lateral The NAT RLatSM trial was initiated in late MoNiToRiNg
deviations. Automated conformance 2015. During Phase 1 of the RLatSM trial, As advanced avionics become standard
monitoring features of ADS, allow for the lateral spacing will be reduced to as low as 25 equipment in more aircraft, IFALPA has
identification of waypoint errors before an NM between three “core” NAT tracks. If encouraged the use of technology to mitigate
aircraft deviates off course. In the most recent successful, the use of RLatSM will expand to all the potential for error. The RLatSM trials in
three month reporting period (April – June NAT Oceanic tracks in late 2016 (Phase 2) and the NAT are a direct result of avionics
2015), over one-half of all lateral errors (24) ultimately to all NAT airspace in 2017. Future advancements. NAT Air Navigation Service
were identified by ADS prior to deviating off plans (2018) anticipate further separation Providers (ANSPs) will be implementing
course. Unfortunately these preventions, along reductions to 15 NM, both laterally and similar advances to perform conformance
with multiple actual deviations of greater than longitudinally. checks on the actual routing being flown by
15 NM, could have been minimized with RLatSM requires the use of “half degree” aircraft. This process will allow the NAT ANSP
proper adherence to Oceanic waypoint latitude waypoints (5130.0N 03000.0W). to compare the cleared Oceanic flight planned
verification procedures. A number of events Previously, all latitude waypoints utilized route with the actual routing in the Flight
occurred when the flight crew received a “whole” degrees (5100.0N 03000.0W). The Management System (FMS). This process will
CPDLC Oceanic clearance containing the diagram below illustrates the potential hazard be accomplished through use of the CPDLC
notation “ROUTE AMENDMENT.” In many in many navigation systems, as ALL of the system. To assist this process it is important for
cases the amended portion of the route was a following waypoints: pilots to be familiar with the CPDLC processes
single Latitude/Longitude waypoint well down N3000.0W05000.0 N3000.0W05030.0 at their airline and specific aircraft type.
line from the Oceanic entry point not noticed N3030.0W05000.0 N3030.0W05030.0 Controllers will send an automated message
by the flight crew. A number of aircraft, will display in an identical manner – UM137 – CONFIRM ASSIGNED ROUTE.
primarily operating routes between Europe N30W050 – on the Navigation Display and For proper automatic conformance processing
and Latin/South America, experienced lateral FMC LEGS page. it will be important for pilots to avoid the use
navigation deviations when operating in the Flight crews must be extremely vigilante in of a free text reply and utilize the aircraft
vicinity of Oceanic fixes – GONAN, PASAS, complying with Oceanic waypoint verification response message DM40 – ASSIGNED
SEPAL, ETIKI, REGHI, BEDRA and SOMAX. procedures. Expansion of the seven-character ROUTE [route clearance]. The [route
A significant amount of ATC coordination FMC waypoint display to the full clearance] portion of the message is
is required within this airspace. East/West automatically inserted by the aircraft avionics
Oceanic flights are crossing with North/South – no manual entry of route information is
flights operating between the U.K. and Spain/ required. Avoidance of free text entries will
Portugal/Canary Islands. The ATC on many allow automated conformance verification of
occasions must modify Oceanic clearances to routing to minimize the potential for Gross
provide appropriate lateral spacing with this Navigation Errors.
traffic Flight crews should closely review While the NAT remains extremely safe, five
CPDLC messages containing “ROUTE Gross Navigation Errors of greater than 25 NM
AMENDMENT” text to ensure proper FMC thirteen-character latitude and longitude occurred during the most recent 90-day
waypoint entries. Some Flight Management values will be required to verify the proper reporting period. The importance of
Systems may “delete or skip” a previously Oceanic waypoint. Some FMC systems may adherence to Oceanic procedures by all flight
entered waypoint when flight crews execute require multiple steps to display the full crews is the key component of maintaining
Strategic Lateral Offset Procedures (SLOP) latitude and longitude coordinates. NAT safety. Technology can help mitigate
immediately prior, or within close proximity, All operators equipped and approved for ADS, errors, but proactive flight crew actions remain
to a waypoint. The waypoint continues to CPDLC and RNP 4 will be eligible for routing the primary safeguard!
display on the ND but no longer appears on
Issue 1 | 2016 InterPilot | The safety and Technical Journal of IFALPA
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