On a typical commercial trans-Atlantic flight, say from Frankfurt (EDDF) to New York Kennedy (KJFK), on a typical airliner (B777, A380, B787, etc.), when are Controller–Pilot Data Link Communications CPDLC established?
- Is it generally before take-off, or just during the flight?
- Is it only used during oceanic crossings, or for continental flights, too?
- Will ATC instruct the pilot when to use CPDLC and when to revert back to voice communications?