Supporting operations, monitoring activities and developing new technologies.

Datalink refers to a system of text message transmission between the aircraft and ground. Operators use datalink to transmit airline operational control messages, or AOC, and flight crew and air traffic controllers can communicate via controller to pilot datalink communications (ATC).

At EUROCONTROL, we support datalink operations, performance monitoring activities, as well as the development and deployment of datalink technologies.

We support the efforts to deploy VDL2  in Europe and prepare for the future datalinks (SATCOM, LDACS and AeroMACS for safety communications) supporting the definition, validation and eventual deployment of the Future Communications Infrastructure (FCI) - a systems of systems comprising legacy and new technologies.

We also help stakeholders monitor their current datalink operations and assist them in resolving technical issues affecting safety, capacity, performance and interoperability on a European level.

Operations and implementation support

Controller–pilot datalink communications (CPDLC) allows air traffic controllers to communicate with pilots over a datalink system. Today, controllers can use data messages instead of voice radio over VHF Datalink Mode 2 (VDL2), an ICAO standardised technology operating in the VHF band.

CPDLC allows certain non-urgent ATC messages to be communicated via text message, rather than voice. The use of CPDLC messages provides several advantages over traditional voice communications. Text-based messages reduce the margin for error due to a poor voice radio connection and they liberate space on the congested VHF channels for more urgent voice communications.

In carrying out datalink performance monitoring, we provide regular performance reports as well as ad-hoc performance reports on request so that individual stakeholders can assess their own performance. We are also able to forecast the future load of datalink and the demand for additional frequencies. In addition, we maintain a database of datalink-related avionics installed on aircraft operating in Europe.

We provide stakeholders with appropriate assistance and advice in implementing EC Regulation No 29/2009 as amended by the Implementing Regulation (EU) 310/2015 (referred to as “DLS Regulations”). This support is available through the Datalink Services – Central Reporting Office (DLS-CRO). We deliver: 

  • monthly performance reports,
  • datalink monitoring flight reports,
  • ad-hoc performance reports for specific stakeholders,
  • forecasts, and
  • a database of datalink avionics installed on many European aircraft.

Interoperability testing

Through our datalink test facility, we support the interoperability testing of ATN/CPDLC avionics and ground systems prior to their operational use.

We support interoperability testing in three main datalink areas:

  • avionics implementation for:
    • integration testing;
    • non-regression testing;
    • rehearsal for certification process;
    • verification of HMI and functioning of new equipped aircraft;
    • CPDLC familiarisation from equipped aircraft;
    • problem Investigation;
  • ANSP ground implementation for:
    • validation of Network Access;
    • integration testing;
    • declaration of verification;
    • non-regression testing;
    • problem investigation;
  • CSP implementation for:
    • integration testing;
    • non-regression testing;
    • problem investigation.

As part of our interoperability testing support we have developed a controller-pilot datalink communications ground authentication tool to help with ATN/CPDLC datalink testing activities, including verification of installation board equipped aircraft and familiarisation for the crew. Visit our dedicated page to learn more about the tool and how to access it.


Controller-pilot datalink communications ground automated tool


Explore our datalink tools, designed to help with monitoring and support,  in implementation activities, such as problem investigations, as well as helping with problem reporting and interoperability testing requests.



Datalink issue management tool


Datalink statistics reporting and analysis tool

CPDLC at our Maastricht UAC

We use CPDLC at our Maastricht Upper Area Control Centre (MUAC).

Support to the SESAR Deployment Manager (SDM)

We are an active contributor to SDM data link recovery activities and in particular the CEF2017 DLS IP1 project.

With our colleagues at the SESAR Deployment Manager, we are defining a plan of specific direct support.

Guidance on the air-ground datalink services for military operators

We provide support on the civil-military interoperability aspects. The DLS regulations lay down requirements on datalink services for the Single European Sky also for military users. Articles 3 and 8 of the Regulation 29/2009 contain provisions which affect State aircraft. The Regulation promotes the forward-fitting of transport-type State aircraft with the appropriate equipment where the military decide to equip aircraft with the civil datalink capability. Details on the applicability of the Regulation to State aircraft can be found in our CMAC CNS factsheet.

Future Communications Infrastructure

VDL2 is the first datalink, which will provide benefits and capacity in the short term.

In the longer term, VDL2 will be complemented by new datalinks, with increased capacity requirements and new, more stringent operational needs.

The ICAO GANP roadmap and European ATM Master Plan identify three new datalinks to support safety services offering global interoperability: AeroMACS, the future airport surface communication subnetwork, future satellite communication (SATCOM) for Oceanic purposes and LDACS a line-of-sight communications subnetwork for continental coverage, For non-safety services, commercial technologies may also be introduced as needed by airspace users.

These links are part of the multilink concept considered as a technological enabler for many new air traffic management concepts including trajectory-based operations.

More about our datalink projects


Satellite communications datalink


L-band digital aeronautical communication system


Aeronautical mobile airport communications system datalink