An AIRPROX is a situation in which, in the opinion of a pilot or 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 AIRPROX may occur as a result of ATC clearances, a Level Bust or Airspace Infringement.

An AIRPROX is commonly referred to as a Near Midair Collision (NMAC) in the USA; however, they are not

precisely the same as a comparison of their definitions demonstrates. Whereas an NMAC is always an

AIRPROX, an AIRPROX is not necessarily a NMAC.


ICAO defines a series of classifications for AIRPROX events.

It is required that this classification should be assigned on the basis only of actual risk, not potential risk.

This means that only the residual risk after any avoiding action is considered.

The available classification categories are:
  • A - Risk of collision: aircraft proximity in which a serious risk of collision has existed.
  • B - Safety not assured: aircraft proximity in which the safety of the aircraft may have been compromised.
  • C - No risk of collision: aircraft proximity in which no risk of collision has existed.
  • D - Risk not determined: aircraft proximity in which insufficient information was available to determine the risk involved, or inconclusive or conflicting evidence precluded such determination.
The definition and classification of an AIRPROX given above was agreed prior to the introduction of radar systems.

Reporting and Investigation of an AIRPROX

ICAO requires the establishment of AIRPROX reporting and investigation procedures. National authorities establish a special committee to investigate AIRPROX reports which allocates the actual risk classification and to recommend further action

Chapter §3 of ICAO Safety Management SARP’s (Standards and Recommended Practices) is not applicable in IVAO network. It is just given for information only.

See also

  • None



  • VID 150259 - Creation
  • VID 150259 - Wiki integration


  • 00:26, 14 May 2021


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