ICAO airport code

These codes, as defined by the International Civil Aviation Organization and published quarterly in ICAO Document 7910: Location Indicators, are used by air traffic control and airline operations such as flight planning.

The recommendations for ICAO airport codes were adopted on 24 March 1959, and came into force on 1 October the same year.

For example, the ICAO code for Heathrow International Airport in London, is EGLL, with EG reflecting that it is based in the United Kingdom.

Brussels Airport in Brussels, Belgium, has the ICAO code EBBR for its civilian facilities, and Melsbroek Air Base has been assigned ICAO code EBMB, even though the two airports share runways and ground and air control facilities.

For larger countries like the UK or Germany this is not feasible, given the limited number of letter codes.

The French Federation of Ultralight Motorized Gliders was formally named the keeper of these codes.

[4] In Antarctica many aerodromes have pseudo ICAO-codes with AT and two digits, while others have proper codes from countries performing air control such as NZ for New Zealand.