I've seen ACARS and ATSU used interchangeably and I've seen references that imply they're different things (ATSU being Airbus only).

How would I explain the difference to someone?


1 Answer 1


ATSU is a computer. It is the successor to the ACARS Management Unit (MU). ATSU is at the center of the FANS development of Airbus aircraft.

ACARS, as a function, provides Aircraft-Airline communications using text and reports (AOC function). CPDLC function, on the other hand provides Aircraft-ATC communication using text (ATC function).

ACARS, as a datalink, provides communication infrastructure for both AOC and ATC functions.

In the future, the ACARS communication network will be superseded by something called Aeronautical Telecommunication Network (ATN). It will be like the Internet where other networks can get hooked up.

  • $\begingroup$ Welcome to Av.SE! Nice answer - please come back often. $\endgroup$
    – Ralph J
    Aug 19, 2022 at 1:15
  • $\begingroup$ While technically the above statements are correct to some degree ATSU can also refer to Air Traffic Service Unit and as defined in Skybrary (skybrary.aero/articles/air-traffic-service-ats) this could also be a reference to a provider of aviation services such as air traffic control. The ATSU that @MANN is referring to is an avionics computer that is built by Airbus but that is just a name (like Kleenex tissues). $\endgroup$
    – jbolt
    Jan 4, 2023 at 13:41
  • $\begingroup$ Aircraft Communications, Addressing and Reporting System (ACARS) is technically any equipment that meets the specification by which aircraft communicate with ground systems including but not limited to CPDLC (Controller Pilot Data Link Communications) a sort of structured text based command communication specification, ADS-C (Automatic Dependent Surveillance Contract) specification as well as AOC (Airlines Operation Center) type communications which could range from messaging for services such as refueling or deicing to proprietary communications between an airline fleet and its owners $\endgroup$
    – jbolt
    Jan 4, 2023 at 13:47

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