ARINCDirect's Most Frequently Asked Questions - ATN CPDLC in Europe

Welcome back to Jump Seat. Today we’ve once again turned our platform over to our ARINCDirect FANS (ADFANS) trainer, Jen Johnson, to share her most frequently asked questions regarding Eurocontrol’s ATN Datalink.

Q: Where can I find the most up to date ‘best practices’ for using CPDLC in Europe?

Beginning last year, Eurocontrol has created a resource guide for CPDLC prior to the very busy summer season across their airspace (usually released around May-June); the 2026 edition can be found here. There is also a lot of great operational information located in the Eurocontrol: Datalink FAQ.

Q: Where can I find guidance on how to file my flight plan?

Eurocontrol offers the following filing guidance (click here for a quick-reference page): 

Aircraft is ATN equipped and is exempt

• Crew are trained and intend to use ATN during the flight: 
• File J1 in field 10  
• Make sure your CODE/ in Item 18 contains your correct ADS-B Mode S Address, also known as the “ICAO Address”. If missing, the flight plan will be rejected. If incorrect, you will not be able to logon to ATN.  
• Flight plans should not contain the J1 code if the crew is not trained and ready to use CPDLC.  
• Crew does not intend to use ATN during the flight: 
• File DAT/CPDLCX in field 18 
• File “Z” in field 10a  

Note: Flights made by aircraft that are both exempt and equipped should not file both a J1 and a DAT/CPDLCX code; file one or the other depending upon the crew’s intent.  

Aircraft is not ATN equipped 

• Aircraft is exempt. 
• File DAT/CPDLCX in field 18 
• File “Z” in field 10a 
• Aircraft is not exempt. 
• Nothing should be filed for CPDLC/ATN, and the flight must file and operate at or below FL285. 
• Flights filed above FL285 while filing no datalink codes will be rejected. 

Q: What is the Logon List?  

The Logon List, operated by the airspaces below shaded blue, is a list of registered aircraft that is intended to prevent aircraft with known avionics issues from logging on and participating in ATN CPDLC. Only aircraft registered on the Logon List will be able to connect to ATN in these ANSPs: 

The Logon List is updated every AIRAC cycle, however, applications must be received about a month early. Please see this link for registration details.

Q: If I am NOT registered on the Logon List, am I still in compliance with the Datalink regulation? Will I suffer any restrictions?

Logon List registration does not affect whether an aircraft is considered compliant with the datalink regulation; aircraft not on the Logon List will still be considered compliant with the regulation if they are equipped in accordance with the regulation: Eurocontrol, EASA. However, you will not be able to connect to ATN CPDLC in the airspaces that require the Logon List (logon attempts in these airspaces will not be connected). 

Did You Know?

• Earlier this year, we covered the most frequently asked questions for CPDLC in the United States domestic airspace, find the article here.
• As an added benefit, ARINCDirect datalink subscribers have access to our FANS Automated Test Stations. This quick test allows customers to test the functionality of CPDLC and ADS-C anytime, anywhere, while connected to the ARINCDirect network. For more information on ARINCDirect FANS automated quick testing, please contact ADFANS@collins.com.
• Need to manage and adjust your aircraft equipment codes? ARINCDirect account admins can access the Tails section under the My Company tab on the ARINCDirect website. Select your tail, make your changes, and be sure to click Save. Need assistance? Contact the 24/7 ARINCDirect Flight Operations team at ad-flightops@collins.com.

Useful Links

• Eurocontrol Network Status (implementation maps, logon codes, logon list, VDLM2 radio frequencies, FANS accommodation in European airspace)
• Implementation Status Table (detailed implementation information listed by country)  
• Logon List (full details on the Logon List)
• Eurocontrol: Datalink FAQ (Flight Crew Ops Use of Datalink, the “Why’s” of datalink use in Europe, Flight Plans, General information on datalink)