Originally Posted by
dc9-32
Show me a link that states CPDLC is mandatory in Europe.
Try this:
www.easa.europa.eu/the-agency/faqs/airspace-usage-requirements-dlscpdlc-controller-pilot-data-link-communication
"The DLS IR [Data Link Services Implementing Rule] is an airspace requirement and is applicable for all IFR GAT flights operating above FL285."
Since February this year AFAIR.