If my aircraft is compliant with the DLS IR and the flight crew trained, however my aircraft also qualifies for CPDLC exemptions, what shall I insert in the flight plan?
If the operator voluntarily decides to comply with DLS IR (aircraft capable + crew trained), J1 designator should be used in item 10 of the flight plan in accordance with ICAO PANS-ATM. In this case, even of the aircraft is eligible for CPDLC exemption, the flight plan should not reflect CPDLC exempt status.
If the operator decides to declare its CPDLC exempt status, flight plan should reflect that the aircraft is exempted by including letter “Z” in item 10 and the indicator “DAT/CPDLCX” in item 18 of each flight plan.
In this case, J1 designator should not be used in the flight plan even if the aircraft is technically capable. Nonetheless, if properly equipped and compliant with the DLS IR, operators are encouraged to use the CPDLC capability on board.
For further details on how to reflect the CPDLC exempt status in the flight plan please check the EASA SIB 2020-03.