Gander’s Bringing Back CPDLC Oceanic Reroutes

On July 2, NAV CANADA is bringing back CPDLC route clearance uplinks for eastbound NAT flights, ending the use of voice clearances that have been required for these route amendments since May 2025.

The change will apply to eastbound flights that receive route amendments from Gander Oceanic, prior to oceanic entry. An AIP SUP will shortly follow on July 9 – the one to look out will be 065/2026.

Instead of receiving a reroute by voice, crews will once again receive a CPDLC uplink in the following format:

CLEARED TO [position] VIA [route clearance]

This is the standard ICAO route clearance format, known in ICAO docs as ‘UM79.’

Why the change?

CPDLC route clearances are preferred because they can be uplinked directly to the FMS, negating the need for error-prone manual entry.

However following the implementation of Canada’s Oceanic Clearance Revision (OCR) in late 2024, problems emerged.

It was identified that some reroute uplinks were creating route discontinuities in the FMS. As a result, NAV CANADA decided to revert to voice clearances for these amendments in May last year while improvements were made to the back end.

Now these issues have been fixed.

What’s different?

Under the previous system, a route amendment could terminate at a waypoint that wasn’t connected to the remainder of the active flight plan, creating a route discontinuity in the FMS. Crew then had to manually reconnect the route before oceanic entry.

With the new system (effective July 2), the ‘CLEARED TO’ waypoint will be a waypoint already contained in the filed flight plan, either within oceanic airspace or after oceanic exit. The amended route strings automatically with the existing plan, allowing the route to be loaded without creating a disco (of the non-musical variety 🪩).

For crew, this will make eastbound oceanic reroutes easier to load and review prior to NAT entry.

Crew Errors

All sounds pretty straight forward, right? Well it is, but with some important caveats.

Pilot error when handling CPDLC route amendments remains a persistent issue across at the NAT region.

Last month, EUROCONTROL published some guidance highlighting several common CPDLC mistakes made by flight crews, many of which create significant workload for controllers or lead to clearance busts.

We covered this in a seperate article, and the lessons apply just as much in oceanic airspace as they do in Europe.

With this update, NAV CANADA reiterates many of the same precautions – especially the importance of acknowledging route amendments correctly and not misinterpreting them as ‘direct-to.’

For the avoidance of error, the following flow is suggested whenever a route amendment is received via CPDLC:

We all like to say rog’ immediately. Don’t send ACCEPT/WILCO before you have loaded and executed it!

Quick reminder: OCR hasn’t changed

Gander remains fully in Oceanic Clearance Removal (OCR) mode. In normal human speak that means there’s no oceanic clearance in Gander. You still send an RCL 90-60 mins before the OEP, but it’s for planning only – you’re not requesting an oceanic clearance, and none will be issued. Continue in accordance with your current ATC clearance unless ATC issues a change before the OEP. Once oceanic, any further changes will be issued via CPDLC or HF as required!

The only thing changing on July 2 is how pre-entry route amendments are delivered: they return to CPDLC instead of voice.

Key Docs

This is a significant change for Gander’s airspace. There are two official documents to look out for:

This IATA Bulletin which explains NAV CANADA’s fix in more detail.
SUP 065/2026 (*to be published July 9).

A virtual call on this update has already been held by IATA – remember, July 2 is the change-over.

And for more info on recent North Atlantic changes, check out this post.

Gander’s Bringing Back CPDLC Oceanic Reroutes