Definition
A digital datalink system that allows aircraft to send and receive short text-based messages to and from ground stations, airline operations, and air traffic services using VHF radio, HF radio, or satellite links. ACARS is used for routine operational messages such as weather requests, clearances, position reports, departure and arrival times, and maintenance data, reducing the need for voice radio communication.
Plain English
A system that lets aircraft and ground stations exchange short typed messages instead of talking over the radio. Think of it as a text-messaging service for airplanes.
Context Anchor
In this section of the Instrument Procedures Handbook, ACARS appears as one way a flight crew can receive Digital Automatic Terminal Information Service information in the cockpit.
Derivation
The name describes its function: 'Addressing' refers to how each message is routed to a specific aircraft or ground address, like an email address. 'Reporting' refers to the automatic operational reports the aircraft sends — things like takeoff time, landing time, and engine data.
Why Pilots Care
Reduces voice frequency congestion while delivering reliable, time-stamped operational data directly to the cockpit.
Analogy
ACARS is a little like a secure text-message system for the aircraft. The message goes to a specific place and contains operational information, not casual conversation.
Intuition Check
Do not think of ACARS as normal voice radio. ACARS sends digital messages between the aircraft and ground systems; it is not the pilot talking over a frequency.
Example Sentence 1
The crew received their pre-departure clearance through ACARS rather than reading it back over the radio.
Example Sentence 2
ACARS automatically sent the flight's fuel and position reports to the airline dispatch office.