Datalink in Europe: What Are The Rules?

By David Mumford


CPDLC in Europe can be bamboozling – multiple chunks of airspace, all in close proximity to each other, all with varying levels of operating capability when it comes to datalink. Plus there’s a Logon List to consider. And a Datalink Mandate. And different considerations depending on what kind of CPDLC you’ve got onboard…

So here’s a super simple guide on how it all works, and what the rules are.

Is there a Datalink mandate in Europe?

Yes. The EU datalink mandate is for flights above FL285 throughout Europe. But loads of aircraft are exempt from this, the main two being:

  • Aircraft with a certificate of airworthiness first issued before 1 Jan 2018 and fitted prior to this date with FANS 1/A.
  • Aircraft with 19 seats or less and a MTOW of 45359 kg (100000 lbs) or less, with a first individual certificate of airworthiness issued before 5 Feb 2020.

In addition, in Dec 2019 the EU announced that a bunch of other aircraft were exempt too:

Aircraft permanently exempt:

  • Aircraft in Annex I
  • Aircraft in Annex II with a CofA issued before 5 Feb 2020

Aircraft which had up to 5 Feb 2022 to do the avionics retrofit:

  • Aircraft in Annex II with a CofA issued after 5 Feb 2020
  • Aircraft in Annex III

EASA issued a Bulletin which says that operators who are exempt from the mandate should include the letter “Z” in Field 10 and the indicator “DAT/CPDLCX” in Field 18 of their flight plan. If you don’t, ATC won’t know you’re exempt, and you may struggle to fly above FL285!

Bottom line, for operators who are exempt from the mandate, their flights should not be restricted to the lower flight levels below FL285. Logged-on traffic might just get better directs and faster climbs, that’s all.

So before we press on, if you want to know more about the Datalink Mandate, read our article here.

The Logon List

This is not the same thing as the Datalink Mandate. This is the thing that used to be called the Whitelist. It’s what you need to get registered on to get CPDLC service when flying in Switzerland, Germany, and Maastricht-UAC controlled airspace (i.e. the upper airspace above FL245 over Belgium, the Netherlands and Luxembourg – one of Europe’s busiest and most complex airspace areas.)

Ultimately, if you get your aircraft added to the Logon List, that means you’ll be able to use CPDLC in these areas and will probably get better directs and faster climbs. However, if your avionics are not eligible to be on the Logon List, ATC will NOT restrict you to the flight levels below FL285.

Why is there a Logon List?

Before ATC in Europe had the Logon List, there were still many aircraft with avionics flying around contributing to major connectivity issues – also called “Provider Aborts”.  This made the network unusable for properly equipped traffic, since messages got lost or timed out.

With the Logon List in place, ATC can improve the service quality for those who have the proper equipment and render CPDLC usable. The Logon List filters “bad” avionics which generate more than 150% of the average Provider Abort rate.

For more info, including details of how to get your aircraft registered on the Logon List, check Eurocontrol’s dedicated page here.

Important to note: the Logon List only applies to ATN aircraft – not FANS 1/A. So essentially, if your aircraft only has FANS 1/A, you don’t need to register – but you also won’t be able to get CPDLC across most of Europe (more on that below…)

Where can I get CPDLC in Europe?

Lots of places. Though not everywhere. The latest map that Eurocontrol published on this was in Sep 2022, as per the below, which is kinda handy. But to see the actual latest info, check out their ‘Implementation Status Table’ here.

Click for the current status.

Is CPDLC logon mandatory?

Yes, provided you’ve got ATN CPDLC, here is where logon is mandatory:

  • Maastricht UAC and Karlsruhe UAC
  • LOVV/Vienna FIR (AIP GEN3.4.2.3)
  • EPWW/Warsaw FIR (GEN3.4.3)
  • LCCC/Nicosia FIR (GEN3.4.5.4)
  • LHCC/Budapest FIR (GEN3.2.2.3)
  • LRBB/Bucharest FIR (GEN3.2.2.5)

Know of anywhere else that should be in this list? Let us know.

My plane only has FANS 1/A. Can I get CPDLC in Europe?

The only bits of airspace in Europe where you can still get CPDLC using FANS 1/A are: the London, Scottish and Shannon FIRs. Everywhere else in Europe is only capable of working with ATN CPDLC. As of Aug 2021, Maastricht Upper Airspace no longer supports FANS 1/A. Dual stack aircraft must be reconfigured to logon via ATN, and aircraft with only FANS 1/A will continue to supported by conventional VHF.

Does CPDLC always work perfectly?

No, not always. Some reasons why:

  • There are different levels of implementation and ATC usage of CPDLC across Europe.
  • There are still some logon forwarding issues at some of the ground stations, which means that it’s not always a seamless transition when you cross from one sector of airspace to another.
  • There’s also still a high logon failure rate, which is only partly mitigated by the Logon List.
  • ATC see regular interferences on the CPDLC frequencies caused by a variety of other reasons (voice, background noise, etc) which might lead to connectivity issues at times.

Updating your equipment with the latest software only solves parts of the known issues, so being compliant and having the latest tech does not mean you will always have a system that works 100% perfectly. But hey, don’t sweat it – Eurocontrol are looking into these issues, and working on fixes.

Any more questions?

Send us an email at, and we’ll do our best to get it answered for you!


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David Mumford

David Mumford

News editor, notam sifter, airspace monitor, map maker, and general purveyor of operationally useful flight ops information.


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