Subcommittees & Working Groups

Aeronautical Operational Control (AOC) Subcommittee


The goal of the AOC Standardization Subcommittee is to develop and maintain a set of standardized ACARS AOC messages. The messages to be defined are unique in that they are not modifiable by the airline: (1) the application will be utilized in common by multiple airlines on multiple aircraft types, such as those messages that involve a third party, or (2) the application is embedded in core software that cannot be changed by the airline.


The subcommittee’s work includes the selection and definition of encoding standards for message preparation and transport over ground-ground networks, air-ground links and aircraft networks. The initial task was to develop the format and content of messages to be used on the Airbus A380. These include:

  • Fueling
  • Weight and Balance
  • Electronic Flight Folder (eFF)
  • De-Ice

Other application definitions (e.g., potable water and weather) will be added as the need is identified. Messages exchanged with the Electronic Flight Bag (EFB) are particular candidates for future definition. Refinements of existing messages definitions will be made, in the form of new versions, in response to experience gained from operations and to complement the evolving use of the message(s) by airline users.


While airlines have been at liberty to define AOC messages uniquely for more than 25 years, recent software implementations, particularly those of Weight and Balance and Aircraft Take-off Data have restricted user flexibility in creating a message that serves their airlines unique operations. Project Paper 633 is needed because the airlines are about to lose their traditional ability to uniquely determine the format and content of some traditionally “user-defined” AOC messages. Utility of the selected AOC messages to airlines will be maximized if the format and content are determined by a combination of airlines rather than a single airframe manufacturer. Complex AOC message handling software (e.g. EFB) is usually not developed by airlines themselves; therefore a standard for interchanged messages will help to lower the cost of procuring, modifying and maintaining the respective airborne software and ground system software, especially for airlines with mixed fleets. As airlines often outsource ground handling, an AOC message standard enables direct communication between aircraft and these handling organizations, similar to ATC Datalink communication. The airlines benefit from having a single cost-effective AOC message system, consistent across the different airborne and ground systems. In addition, future data requirements - when implemented by the various avionics vendors - can be more easily and economically satisfied.

AOC Work Program

Additional new applications such as weather forecast uplinks and meterological data downlinks (to be coded in XML format) may be developed in the future.

The AOC Subcommittee has the responsibility for developing new data link applications - a task formerly shared with the DLK Systems Subcommittee.