Aircraft Accident
An occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight until such time as all persons have disembarked, in which : a) a person is fatally or seriously injured as a result of being in the aircraft, or direct contact with any part of the aircraft including parts which have become detached from the aircraft, or direct exposure to a jet blast except when the injuries are from natural causes, self inflicted or inflicted by other persons, or when the injuries are to stowaways hiding outside the areas normally available to the passengers and crew; b) the aircraft incurs substantial damage or is destroyed; c) the aircraft is missing or is completely inaccessible.
Note: An aircraft is considered to be missing when the official search has been terminated and the wreckage has not been located.
Aircraft Address
A unique combination of 24 bits available for permanent assignment to an aircraft for the purpose of air ground communications, navigation and surveillance.
Note : The aircraft address is also referred to as the Mode S address or the aircraft Mode S address in the context of SSR Mode S.
Aircraft Call Sign
A group of alphanumeric characters used to identify an aircraft in air-ground communications.
Aircraft Collision Avoidance System Version 1
An ACAS which provides information as an aid to "see and avoid" action but does not include the capability for generating resolution advisories (RAs).
Aircraft Collision Avoidance System Version 2
An ACAS which provides vertical resolution advisories in addition to Traffic Advisories (TAs).
Aircraft Collision Avoidance System Version 3
An ACAS which provides vertical and horizontal resolution advisories (RAs) in addition to traffic advisories (TAs).
Aircraft Communications
System operated by SITA to facilitate digital data communication frequency range of voice.
Aircraft Communications Addressing and Reporting System
Recognising the advantage of data communications, the air transport industry introduced a VHF data transport using ACARS in 1978. The system is mainly supporting AOC type communications. ACARS uses a character-oriented air-ground protocol, which is presently also used for satellite communications. The explosive growth in use and new applications require migration to a more efficient bit-oriented data transport communication system compatible with the ATN concept.