The assignment of these codes is governed by IATA Resolution 763,[5] and it is administered by the IATA's headquarters inMontreal, Canada. The codes are published semi-annually in the IATA Airline Coding Directory.
IATA also provides codes for airport handling entities, and for certain railway stations.[6]
Airport codes arose out of the convenience that the practice brought pilots for location identification in the 1930s. Initially, pilots in the United States used the two-letter code from theNational Weather Service (NWS) for identifying cities. This system became unmanageable for cities and towns without an NWS identifier, and the use of two letters allowed only a few hundred combinations; a three-letter system of airport codes was implemented. This system allowed for 17,576 permutations, assuming all letters can be used in conjunction with each other.[7]
In the early days of aviation, airport codes frequently adopted (or were required to comply with) the naming conventions previously established byweather stations,railway stations, and other commercial or governmental outposts that communicated by radio or telegraph. The code names for those stations, which usually predated the use oftwo-way radio and evenradiotelephony itself, reflected the need for terse, standardized signaling patterns that could be easily transmitted and correctly received viaradiotelegraphy andMorse code.
Canada's unusual codes, which bear little to no similarity with any conventional abbreviation to the city's name (such asYUL inMontréal andYYZ inToronto), originated from the two-letter codes used to identify weather reporting stations in the 1930s. The letters preceding the two-letter code follow the following format:
Y – for"Yes", this letter was used when the station shared its location with an airport.
W – for"Without", when the weather-reporting station did not share its location with an airport.
X – suggesting that the last two letters of a code were already in use by a Canadian airport.
Z – indicated that an airport code had been used for the identification of an airport in the U.S.
Most large airports in Canada have codes that begin with the letter "Y",[8][unreliable source?] although not all "Y" codes are Canadian (for example,YUM forYuma, Arizona, andYNT forYantai, China), and not all Canadian airports start with the letter "Y" (for example,ZBF forBathurst, New Brunswick). Many Canadian airports have a code that starts with W, X or Z, but none of these are major airports. When theCanadian transcontinental railroads were built, each station was assigned its own two-letterMorse code:
When the Canadian government established airports, it used the existing railway codes for them as well. If the airport had a weather station, authorities added a "Y" to the front of the code, meaning "Yes" to indicate it had a weather station or some other letter to indicate it did not. When international codes were created in cooperation with the United States, because "Y" was seldom used in the United States, Canada simply used the weather station codes for its airports, changing the "Y" to a "Z" if it conflicted with an airport code already in use. The result is that most major Canadian airport codes start with "Y" followed by two letters in the city's name (for example,YOW forOttawa,YWG forWinnipeg,YYC forCalgary, orYVR forVancouver), whereas other Canadian airports append the two-letter code of the radio beacons that were the closest to the actual airport, such asYQX inGander orYXS inPrince George.[citation needed]
Four of the ten provincial capital airports in Canada have ended up with codes beginning with YY, including:
Canada's largest airport is YYZ[9] forToronto Pearson (as YTZ was already allocated toBilly Bishop Toronto City Airport, the airport was given the station code ofMalton, Mississauga, where it is located). YUL is used forMontréal–Trudeau (UL was the ID code for the beacon in the city ofKirkland. While these codes make it difficult for the public to associate them with a particular Canadian city, some codes have become popular in usage despite their cryptic nature, particularly at the largest airports. Toronto's code has entered pop culture in the form of "YYZ", a song by the rock bandRush, which utilizes the Morse code signal as a musical motif. Some airports have started using their IATA codes asbrand names, such asCalgary International Airport (YYC)[10] andVancouver International Airport (YVR).[11]
Numerous New Zealand airports use codes that contain the letter Z, to distinguish them from similar airport names in other countries. Some examples areHLZ forHamilton,ZQN forQueenstown, andWSZ forWestport.
In addition, sincethree letter codes starting with Q are widely used in radio communication, cities whose name begins with "Q" also had to find alternate codes, as in the case of:[citation needed]
Even this practice is not followed universally. For instanceOwerri in Nigeria uses the codeQOW.
IATA codes should not be confused with theFAA identifiers of U.S. airports. Most FAA identifiers agree with the corresponding IATA codes, but some do not, such asSaipan, whose FAA identifier is GSN and its IATA code is SPN, and some coincide with IATA codes of non-U.S. airports.[citation needed]
For many reasons, some airport codes do not fit the normal scheme described above. Some airports, for example, cross several municipalities or regions, and therefore use codes derived from a combination of their letters, resulting in:
The code also sometimes comes from the airport's former name, such asOrlando International Airport's MCO (forMcCoy Air Force Base), or Chicago'sO'Hare International Airport, which is coded ORD for its original name:Orchard Field. In rare cases, the code comes from the airport's unofficial name, such asKahului Airport's OGG (for local aviation pioneer Jimmy Hogg).
In large metropolitan areas, airport codes are often named after the airport itself instead of the city it serves, while another code is reserved which refers to the city itself which can be used to search for flights to any of its airports. For instance:
Bucharest (BUH) –Otopeni (OTP) is named after the town ofOtopeni where the airport is located, while the city also has a business airport inside the city limits namedBăneasa (BBU).
Berlin (BER) –Self-named (BER). The city also previously had three airports,Tempelhof (THF),Schönefeld (SXF) andTegel (TXL), with THF and TXL both now closed. The former Berlin Schönefeld Airport was absorbed into Berlin Brandenburg Airport, with the old Schönefeld terminal becomingTerminal 5.
Sometimes, a new airport is built, replacing the old one, leaving the city's new "major" airport (or the only remaining airport) code to no longer correspond with the city's name. The original airport in Nashville, Tennessee, was built in 1936 as part of the Works Progress Administration and called Berry Field with the designation, BNA. A new facility known as Nashville International Airport was built in 1987 but still uses BNA. This is in conjunction to rules aimed to avoid confusion that seem to apply in the United States, which state that "the first and second letters or second and third letters of an identifier may not be duplicated with less than 200nautical miles separation."[7] Thus, Washington, D.C. area's three airports all have radically different codes: IAD forWashington–Dulles, DCA forWashington–Reagan (District of Columbia Airport), and BWI forBaltimore (Baltimore–Washington International, formerly BAL).[7] Since HOU is used forWilliam P. Hobby Airport, the newHouston–Intercontinental became IAH.[7] The code BKK was originally assigned toBangkok–Don Mueang and was later transferred toSuvarnabhumi Airport, while the former adopted DMK. Meanwhile,Tan Son Nhat Airport keeps itsSaigon-inspired SGN code even though the city has long been renamed toHo Chi Minh City, and the city's new primary airportLong Thanh International adopts a brand new code LTH after its own name rather than any derivatives from the name of the city that it serves or the legacy SGN designation. The code ISK was originally assigned toGandhinagar Airport (Nashik's old airport) and later on transferred toOzar Airport (Nashik's current airport).Shanghai–Hongqiao retained the code SHA, while the newerShanghai–Pudong adopted PVG. The opposite was true forBerlin: the airportBerlin–Tegel used the code TXL, while its smaller counterpartBerlin–Schönefeld used SXF; theBerlin Brandenburg Airport, which reuses much of Schönefeld's infrastructure, has the airport code BER, which is also part of its branding. The airports ofHamburg (HAM) andHannover (HAJ) are less than 100 nautical miles (190 km) apart and therefore share the same first and middle letters, indicating that this rule might be followed only in Germany.
InUkraine:IEV forKyiv (formerly Kiev),VSG forLuhansk (formerly Voroshilovgrad),KGO forKropyvnytskyi (formerly Kirovograd),LWO forLviv (formerly Lwów while part of Poland until 1939, and still called Lvov in Russian), andIFO forIvano-Frankivsk (in Soviet times spelt in Russian as Ivano-Frankovsk);
Orlando International Airport was founded as Orlando Army Air Field #2 but uses MCO for having been renamedMcCoy Air Force Base in 1959 in honor of a wing commander who crashed at the field in 1958. It was converted in the early 1960s to joint civilian/military use and renamed Orlando Jetport at McCoy, then renamed Orlando International Airport in the early 1980s.
Spokane International Airport was so named in 1960 but goes by GEG because it was built on the former Geiger Field, renamed in 1941 for MajorHarold Geiger when the US Army acquired it.
Louis Armstrong New Orleans International Airport was originally named Moisant Field after daredevil aviatorJohn Moisant, who died in 1910 in an airplane crash on agricultural land where the airport is now located. Its IATA code MSY was derived from Moisant Stock Yards, as Lakefront Airport retained the code NEW.
Other airport codes are of obscure origin, and each has its own peculiarities:
Nashville usesBNA for its former name as Berry Field, henceforthBerryNashvilleAirport.
Louisville Muhammad Ali International Airport isSDF forStandifordField, its original name (Elisha David Standiford who, as a businessman and legislator, played an important role in Louisville transportation history and owned part of the land on which the airport was built.)[13]
Sunshine Coast, Australia, usesMCY due to its former namesMaroochydore Airport andMaroochydore-Sunshine Coast Airport. It is actually located inMarcoola rather than Maroochydore.
Some cities have a local name in their respective language which is different from the name in English, yet the airport code representsonly the English name. Examples include:
Due to scarcity of codes (the three-character code is used by a maximum of 17,576 airports worldwide only), some airports are given codes with letters not found in their names:
A lot of minor airfields without scheduled passenger traffic haveICAO codes but not IATA codes, since the four letter codes allow a larger number of codes. IATA codes are mainly used for passenger services such as tickets andchecked luggage, while ICAO codes are used by pilots. In the US, such airfields useFAA codes instead of ICAO.
There are airports with scheduled service for which there are ICAO codes but not IATA codes, such as Nkhotakota Airport/Tangole Airport inMalawi orChōfu Airport in Tokyo, Japan. There are also several minor airports inRussia (e.g.,Omsukchan Airport) which lack IATA codes and instead useinternal Russian codes for booking. Flights to these airports cannot be booked through the international air booking systems or have international luggage transferred there, and thus, they are booked instead through the airline or a domestic booking system. Severalheliports in Greenland have 3-letter codes used internally which might be IATA codes for airports in distant countries.[citation needed]
There are several airports with scheduled service that have not been assigned ICAO codes that do have IATA codes, especially in the U.S. For example, several airports in Alaska have scheduled commercial service, such asStebbins andNanwalek, which use FAA codes instead of ICAO codes.
Thus, neither system completely includes all airports with scheduled service.
