CPDLC

CPDLC (Controller-Pilot Data Link Communications) is a digital text-based communication system that allows ATC and pilots to exchange routine messages via data link instead of voice radio.

CPDLC reduces radio congestion, eliminates misunderstandings from voice communication, and provides a written record of all exchanges.

• Messages include clearances, requests, reports, and instructions
• Standard message sets defined by ICAO (e.g., "CLIMB TO FL370", "REQUEST DIRECT TO")
• Pilot can respond with WILCO, UNABLE, STANDBY, or ROGER
• Mandatory in many oceanic and high-altitude airspace (NAT HLA, EUR RVSM)
• Uses FANS (Future Air Navigation System) or ATN (Aeronautical Telecommunication Network) standards