Aircraft Proximity
A situation in which, in the opinion of a pilot or a air traffic services personnel, the distance between aircraft as well as their relative positions and speed have been such that the safety of the aircraft involved may have been compromised. An aircraft proximity is classified as follows : a) Risk of collision : the risk of classification of an aircraft proximity in which serious risk of collision has existed; b) Safety not assured : the risk classification of an aircraft proximity in which the safety of the aircraft may have been compromised; c) No risk of collision : the risk classification of an aircraft proximity in which no risk of collision has existed; d) Risk not determined : the risk classification of an aircraft proximity in which insufficient information was available to determine the risk involved, or inconclusive or conflicting evidence precluded such determination.
Aircraft Segment
See also Total System
That portion of the total system located on the aircraft. Aircraft Track Stop Position Error See Track Stop Position Error. Aircraft Track Stop Position Standard Deviation See Position Standard Deviation Aircraft Track Stop Rate Airport See Track Stop Rate. Aircraft Autonomous Integrity Monitoring An integrity monitoring concept where satellite independent data onboard the aircraft is used to guarantee a specific level of integrity for the integrated satellite on board sensor system. Airfile Flight Plan A flight plan filed by the commander of a flight by radio with an ATS unit after departure. Air-Ground Air-Ground refers to two-way communication between aircraft and stations or locations on the surface of the earth. Air-to-ground communications refers to a one-way communication from aircraft to stations or locations on the surface of the earth. For example, data which is transmitted from on-board airborne equipment to ground stations is considered an A/G transmission. Air-Ground Communication Two-way communication between aircraft and stations or locations on the surface of the earth. Air-Ground Control Radio Station An aeronautical telecommunication station having primary responsibility for handling communications pertaining to the operation and control of aircraft in a given area. Airline Operational Communications Within the future Aeronautical Telecommunication Network (ATN) airline operational communications will utilise a set of data communications protocols based on the International Organisation for Standardisation (ISO) Open Systems Interconnection (OSI) reference model, and will link the various air-ground and ground-ground data systems together. Voice and data transmissions associated with airline operational communications will be routed via a gateway known as an ATN Router. Routers will choose the optimum route (i.e. HF link, Gate link, VHF link, mode S and/or Satellite to get messages to users. In doing so, global airline operational communications will be able to more routinely harmonise with all aeronautical data communication service users associated with the international aviation environment.