Location Identifier - FAA Identifier

FAA Identifier

The Federal Aviation Administration identifier is a three-letter or four-letter alphanumeric code identifying United States airports. They were developed in the 1960s, replacing an old system that relied on plain language, teletype station identifiers, and weather reporting codes.

For nearly all major airports, the letters are alphabetic three-letter codes, such as SFO for San Francisco International Airport. Minor airfields typically have a mix of alphabetic and numeric codes, such as 8N2 for Skydive Chicago Airport and 0B5 for Turners Falls Airport. Private airfields have a four-letter identifier, such as 1CA9 for Los Angeles County Fire Department Heliport. The system is designed to mesh with the Transport Canada Identifiers described below.

The FAA is the authority for assigning three-letter identifiers (except those beginning with the letters N, W, Y, and Z), three and four character identifiers, and five-letter name codes for the United States and its jurisdictions. The Department of the Navy assigns three-letter identifiers beginning with the letter N for the exclusive use of that Department. The block beginning with letter Q is under international telecommunications jurisdiction and is used by FAA Technical Operations to capture National Airspace equipment not published in this order.

Three-letter identifiers are assigned as radio call signs to aeronautical navigation aids; to airports with a manned air traffic control facility or navigational aid within airport boundary; to airports that receive scheduled route air carrier or military airlift service, and to airports designated by the United States Customs Service as Airports of Entry. Some of these identifiers are assigned to certain aviation weather reporting stations.

Most one-number, two-letter identifiers have been assigned to aviation weather reporting and observation stations and special-use locations. Some of these identifiers may be assigned to public-use landing facilities within the United States and its jurisdictions, which do not meet the requirements for identifiers in the three-letter series. In this identifier series, the number is always in the first position of the three-character combination.

Most one-letter, two-number identifiers are assigned to public-use landing facilities within the United States and its jurisdictions, which do not meet the requirements for identifiers in the three-letter series. Some of these identifiers are also assigned to aviation weather reporting stations.

• One-letter, two-number identifiers are keyed by the alphabetical letter. The letter may appear in the first, middle or last position in the combination of three characters. When the letter signifies an Air Traffic Control Center's area, the assignment will not change if the Center's boundaries are realigned.

• Identifiers in this series, which could conflict with the Victor, Jet or colored airway numbers are not assigned.

Two-letter, two-number identifiers are assigned to private-use landing facilities in the United States and its jurisdictions which do not meet the requirements for three-character assignments. They are keyed by the two-letter Post Office or supplemental abbreviation of the state with which they are associated. The two letter code appears in the first two, middle, or last two positions of the four character code.

The use of the FAA identifier system in meteorology ended in 1996 when airways reporting code was replaced by METAR code. The METAR code is dependent wholly on the ICAO identifier system.