Definition
A method of exchanging information between an aircraft and ground-based stations by sending digital text messages over a radio or satellite link, rather than by spoken voice on a radio frequency. Used for clearances, weather updates, position reports, and routine communications between flight crews and air traffic control or airline operations.
Plain English
Instead of talking to controllers over the radio, the aircraft and people on the ground send each other typed messages through a digital connection. The messages appear on a screen in the cockpit and on the controller's screen on the ground.
Context Anchor
Seen in Flight Management System discussions, especially where the aircraft can receive clearances, route updates, weather, or other operational information electronically.
Derivation
Data link' simply means a connection that carries data (digital information) instead of voice. 'Air/ground' tells you the two ends of that connection -- one in the aircraft, one on the ground. Naming it this way distinguishes it from voice radio, which has been the traditional way to communicate.
Why Pilots Care
Reduces radio congestion and allows clearer, more reliable delivery of complex clearances and instructions.
Grounding Statement
Instead of hearing every instruction by voice, the crew may receive some information as a readable electronic message in the cockpit.
Intuition Check
Do not assume “communications” here means only talking on the radio. In this term, it means digital messages passed between the aircraft and the ground.
Example Sentence 1
Before crossing into oceanic airspace, the crew logged on to air/ground data link communications so they could send position reports to the controller without using HF voice.
Example Sentence 2
Air/ground data link communications let the aircraft automatically report its position to ATC.