International Ops 2018

Flight Service Bureau | OPSGROUP

Tag: ICAO NAT

New CPDLC procedure on the NAT

There’ll soon be a new CPDLC procedure on the NAT, designed to prevent pilots from acting on any old CPDLC messages that might have been delayed in the network.

ICAO have published a new Bulletin for all the NAT Air Navigation Service Providers (ANSP’s) to use as a basis for implementing this new procedure. They recommend that all aircraft should receive a message immediately after they enter each control area telling them to “SET MAX UPLINK DELAY VALUE” to a certain number of seconds. The idea is that this will prompt the pilot to enter the specified latency value into the aircraft avionics, so that it will ignore/reject any old CPDLC messages.

So far, only Iceland’s BIRD/Reykjavik FIR have implemented this procedure, effective May 24. All other sectors of NAT airspace (Gander, Shanwick, Bodo, Santa Maria, New York Oceanic) are busy writing their own AIC’s and will implement later in the year. 

So when entering the BIRD/Reykjavik FIR, expect to receive a CPDLC message from ATC instructing you to “SET MAX UPLINK DELAY VALUE TO 300 SECONDS”. A copy of their AIC with more guidance can be found here.

The latency monitor function varies from one aircraft type to another: some just automatically reject old CPDLC messages, some will display a warning to the pilot that the message has been delayed, some have deficient equipment, and some do not have the message latency monitor function implemented at all.

Because of this, ICAO note that “it is impossible for ATC to tailor the uplink of the message… to different aircraft types. It has therefore been decided among the NAT Air Navigation Service Providers (ANSPs) to uplink this message to all CPDLC connected aircraft immediately after they enter each control area. An aircraft may therefore receive this message multiple times during a flight.”

So here’s the lowdown on what you need to do:

1. Work out in advance what kind of message latency monitor function your aircraft has, and what it is designed to do when it receives the CPDLC message “SET MAX UPLINK TIMER VALUE TO XXX SECONDS”.

2. When you receive this message, respond with the voice message “ACCEPT” or “ROGER”. If your aircraft has a functioning message latency monitor, punch in the specified number of seconds. If you don’t have functioning equipment, respond with the free text message “TIMER NOT AVAILABLE”.

3. If anything goes wrong, revert to voice comms.

Back in November 2017, we reported on an equipment issue with Iridium satcom that prompted a ban by a number of Oceanic ATC agencies. Some aircraft were receiving massively delayed clearances sent by ATC via CPDLC – and one took the instruction and climbed 1000 feet, even though the message was meant for the flight the aircraft operated previously.

Although the bans were dropped after Iridium fixed the problem at ground level (by ensuring the system no longer queued CPDLC uplinks for more than five minutes), this new CPDLC procedure on the NAT should ensure this kind of situation doesn’t happen again. It’s officially being brought in as one of the safety requirements for the roll-out of reduced lateral and longitudinal separation minima across the NAT, which is predicated on Performance Based Communication and Surveillance (PBCS) specifications – that means having CPDLC capable of RCP240 (4 minute comms loop), and ADS-C capable of RSP180 (3 minute position reporting).

Further reading:
ICAO NAT Bulletin 2018_002: CPDLC Uplink Message Latency Monitor
Iceland’s AIC on the new CPDLC procedure for the BIRD/Reykjavik FIR
– The latest PBCS rumours and facts
The latest NAT changes, including EGGX/Shanwick, CZQX/Gander, BIRD/Iceland, ENOB/Bodo, LPPO/Santa Maria, and KZWY/New York Oceanic East.
IRIDIUM satcom fault fixed

2018 Edition: New NAT Doc 007 2018 – North Atlantic Airspace and Operations Manual

For the latest changes and updates on the North Atlantic, including our most recent Guides and Charts, use our NAT reference page at flightservicebureau.org/NAT.

2018 version – NAT Doc 007

The 2018 version of NAT Doc 007, North Atlantic Airspace and Operations Manual, was published in January 2018 by ICAO/NAT SPG.

Download the original document here (PDF, 5mB), and see also:



2018
 is off to a flying start again with NAT changes – these are the latest important changes. These are also published in the latest edition of NAT Doc 007, January 2018.

  • PBCS From March 29th 2018, PBCS is a requirement for the NAT Tracks between FL350-390 – RCP240 and RSP180. Read more about PBCS in our article.
  • RLAT  From January 4th 2018, Shanwick and Gander increase the number of RLAT tracks – most tracks between FL350-390 will now be RLAT – 25nm separation between them.

And there will be more! Keep an eye on the FSB NAT Changes page, we’ll keep it updated.

 


Feb 2nd, 2018: FSB updated the full NAT Crossing Guide “My first North Atlantic Flight is tomorrow“.

– What’s different about the NAT, changes in 2018, 2017, 2016, 2015, NAT Quick Map
– Routine Flight Example #1 – Brussels to JFK (up at 5.45am)
– Non Routine-Flights: No RVSM, No RNP4, No HF, 1 LRNS, No HLA, No ETOPS, No TCAS, No Datalink – what you can do and where you can go
Take a look.


NAT Expanded data link mandate

It’s time for everyone’s favourite topic – DATA LINK MANDATE! New things are happening on December 7th. Don’t worry, we’ll help.

Right Now, if you’re using the NAT tracks, between FL350-390, you’re mandated to use data link services. Simply put, you must be equipped with CPDLC and ADS-C (FANS 1/A ready and able).

On December 7th 2017, the data link mandate will expand to the entire ICAO NAT Region between FL350-390, with a few exceptions. We’ve got the image below showing you the area. White routes are exempt, as well as the grey border areas (we like the Big Fish).

Exemptions:
-Everything north of 80°North
-New York Oceanic East FIR (was previously all of NY Oceanic)
-Routes T9, T213, T13, T16, T25. (see: The Tango Routes)
-The Blue Spruce Routes (white lines)
-Areas that currently have radar, multilateration (is this a word?) and/or ADS-B. (the grey areas)
Note: If any of the NAT Tracks go into the grey areas, you won’t be exempt while on the tracks.

Be ready, January 30th, 2020, all of the NAT ICAO Region will have the Data Link Mandate, above FL290, including the Tango Routes as well as those little grey areas.

To figure out where you are welcome on the NAT, depending on what equipment and training you have, check out our quick and dirty guide here.

For more details about the datalink mandate, you can read the UK AIC in full here.

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