ICAOcode

ICAO code refers to a set of four-letter alphanumeric identifiers assigned by the International Civil Aviation Organization (ICAO) to airports and aerodromes worldwide. These codes are used in air traffic control, flight planning, navigation databases, and safety communications. They are distinct from the IATA three-letter airport codes, which are more commonly used by the traveling public and in ticketing. For example, Los Angeles International Airport has the ICAO code KLAX and the IATA code LAX; London Heathrow is EGLL (ICAO) and LHR (IATA).

ICAO codes are issued by the ICAO in coordination with national aviation authorities and reflect regional country prefixes. In the United States, many airports begin with the letter K (such as KJFK or KLAX), while prefixes in other regions vary (for instance, UK airports typically start with EG, Paris with LF, and Berlin with ED). The first one or two letters generally indicate country or region, and the remaining letters identify the specific airport.

In addition to airport codes, the ICAO organization also designates three-letter airline designators used in flight operations to identify carriers (for example, United Airlines uses UAL, Lufthansa uses DLH, British Airways uses BAW). These ICAO airline designators are distinct from the IATA airline codes, though both systems serve to uniquely identify operators in international aviation.

ICAO codes are intended to be unique worldwide and are standardized in international aviation regulations. They appear in aeronautical information publications, flight plans, and air traffic control communications to ensure precise identification of locations and services.