Designating Airport Codes

There's a great comedy skit by Gary Gulman about how the postal service finally settled on its two letter designators for states, but do you know how the three- and four-letter acronyms for airports came about? They basically date as far back as the 1930s when air travel began to pick up in popularity and airfields began to appear more commonly around the globe. Initially, airports were given a two-letter code that corresponded with the National Weather Service coding system, but as more and more airfields appeared, a third letter was added to accommodate the burgeoning airfield construction. There are now over 17,500 airport identifiers in existence!

The International Civil Aviation Organization (ICAO), a representative of the United Nations whose job is to ensure aviation regulations are upheld, is charged with assigning official codes to each airport. These are generally your four-letter abbreviations which contain a country code for the first letter. The International Air Transport Association (IATA), an airline trade association, maintains the three-letter system that most of us are familiar with seeing on our tickets or when searching for airfields to book. Most of the time, these codes are the same, minus the first letter, but not always. The Mesa Gateway Airport ICAO code is KIWA, a nod to its history as Williams Air Force Base, and the IATA code changed with the airport name change in 2011 to AZA. IWA is now the IATA designator for Yuzhny Airport in Ivanovo, Russia.

Some of these codes seem quite logical and simply use the first three letters of the city where the airfield exists, such as ATL for Atlanta or BOS for Boston. Or, perhaps they combine city names such as DFW for Dallas/Fort Worth or MSP for Minneapolis/St. Paul. But then it gets tricky. For example, why in the world is Chicago known as ORD? As it turns out, when the codes were being developed, Orchard Place was a small community just west of the city that contained a military airfield. Since the airfield served as a manufacturing facility for Douglas aircraft, it was known as Orchard Place Airport-Douglas Field and was therefore abbreviated to ORD!

Centennial Airport opened in 1968 as the Arapahoe County Airport, hence the codes KAPA (APA). The airport was renamed to Centennial reflecting the State of Colorado's admission to the Union as the 38^th state in 1876, the centennial of the U.S. Declaration of Independence while the APA code carried on.

If you've traveled often, you may have heard of Derby Field in Lovelock, Nevada that is humorously coded as LOL, or even the Sioux City airport, who after years of petitioning for a new code, decided to embrace the unfortunate label and now markets "Fly SUX" merchandise, which you can even order online, if you're looking for something fun.

Many codes are a historic reference to previous city names, like LED for St. Petersburg, which used to be Leningrad, or BOM for Mumbai, which was previously westernized as Bombay. Others can be created simply to eliminate confusion. Ronald Reagan Washington National Airport is coded DCA since it was previously known as the District of Columbia Airport. Once Dulles was constructed, it was believed that DIA for Dulles International Airport would be too easily confused, so they simply reversed the letters to give us IAD for International Airport Dulles.

Did you know that YYZ for Toronto Pearson airport (look that one up) is located near the hometown of the band Rush? Drummer Neil Peart once admitted that as guitarist Alex Lifeson, a licensed aircraft pilot, flew the band into the airport, he overhead the VHF omni-directional range system broadcasting the Morse code for the airfield. He found the rhythm so interesting that the band went on the record and release a song in 1981 called YYZ!

As you can see, airport codes each have unique history and help us differentiate our destinations easily and accurately. If you're curious about how your own airport got its name, try looking it up—sometimes the stories are quite entertaining!