Some airport codes make sense instantly when you look at them, for example ATL is the three-letter IATA airport code for Hartsfield–Jackson Atlanta International Airport in Atlanta. DFW is the airport in Dallas/Fort Worth. And, Abraham Lincoln Capital Airport, owned by the Springfield Airport Authority, is located in Springfield, Illinois and its three-letter code is SPI (the airport in Springfield Il.).
Not all airport codes make as much sense, however. For example, why are the airports in L.A. and Phoenix LAX and PHX, respectively?
IATA Code History
The International Air Transport Association (IATA) regulates the airport codes, which were created as to make identifying various airports a simpler task. Pilots used to use the two-letter city abbreviations prior to IATA regulation, which were codes taken from the National Weather Service.
IATA Code Logic
The IATA codes are usually abbreviations of the city in which the airport is located. For example, even though the abbreviation DIA would make sense for Denver International Airport, its three-letter code is actually DEN. But in a city like New York, where there is more than one major airport, an abbreviation of the airport name would make more sense (as in the case of JFK, the abbreviated form of John F. Kennedy).
So far, so good. But then we start to see anomalies like Chicago’s O’Hare International Airport. This major airport is neither CHI nor OIA, but rather ORD. Why? The initial designation came from a community west of Chicago called “Orchard Place.” So it was referred to by pilots as “ORD” as an abbreviation for Orchard, and no one ever got around to changing it.
About the “X” in airport codes like LAX (Los Angeles International): it was short-sighted early on, but no one imagined that one day we’d have so many airports that three-letter codes would ever be needed. So LA became LAX. There’s no other deep meaning behind that; it was just as easy as adding an X to the end of the existing airport code.
Abraham Lincoln Capital Airport
Owned by the Springfield Airport Authority, SPI (Abraham Lincoln Capital Airport) follows the logical three-letter coding for the city in which it’s located. This Central Illinois airport supports its passengers with several amenities, like Flight Tracker, the FlySPI Sky Club, a gift shop and other convenient passenger services.