Definition
A digital datalink system that allows aircraft to exchange short text-based messages with airline operations, air traffic services, and ground stations over VHF, HF, or satellite radio links. It is used to send and receive operational information such as flight plans, weather, clearances, position reports, and aircraft system status.
Plain English
A messaging system that lets the aircraft and people on the ground send short text messages back and forth automatically, without having to talk on the radio.
Context Anchor
Seen in flight plan equipment codes, especially when describing an aircraft’s communication or data-message capability.
Derivation
The name spells out the function: it addresses messages to and from a specific aircraft, and reports information back. The word 'datalink' (often used alongside ACARS) simply means a link that carries data instead of voice.
Why Pilots Care
It reduces radio workload, speeds up clearances and reports, and provides a reliable written record of communications.
Intuition Check
ACARS is not a navigation system by itself. It is mainly a messaging and reporting system that can support flight operations.
Example Sentence 1
The crew received their oceanic clearance via ACARS rather than over HF voice.
Example Sentence 2
While taxiing, the crew received the revised departure via ACARS and loaded it directly into the FMS.