ICAO
The United Nations agency that sets international aviation standards, and the source of the four-letter airport codes.
Also written
international civil aviation organization
ICAO codes are structured geographically — K for the contiguous United States, EG for the United Kingdom, LL for Israel — so KJFK, EGLL and LLBG each say where they are before they say what they are. ICAO also issues the three-letter airline designators used in callsigns and the aircraft type designators such as B738 and A21N. TailzIN keys airports on the ICAO code for exactly this reason: it is unique worldwide.
Nearby in Aviation
- holding pattern — A published racetrack circuit an aircraft flies to wait, usually for its turn to approach.
- IATA — The airline trade body whose three-letter codes appear on tickets and baggage tags.
- ILS — A ground-based radio system that guides an aircraft down to the runway on both centreline and descent path.
- landside — The part of an airport before security, open to anyone.