Curious Iowa: How are airport codes designated?

In the aviation industry, airports and airfields are identified by a code. For example, The Eastern Iowa Airport is CID and the Quad Cities International Airport is MLI.

A Cedar Rapids resident wrote to Curious Iowa — a Gazette series that answers readers’ questions about our state and how it works — inquiring about how airport codes are chosen. Sioux Gateway Airport in Sioux City has SUX for its airport code. The reader wanted to know whether that code could be changed.

We dove into the topic and the history surrounding airport codes, how they are designated and whether they can be changed.

Who designates airport codes?

The International Air Transport Association (IATA) is a trade association for airlines. IATA assigns the 3-letter airport codes you’ll find on your tickets and luggage. There is also the International Civil Aviation Organization (ICAO) which designates the 4-letter codes that are used for air traffic control purposes. For example, The Eastern Iowa Airport’s ICAO code is KCID and Quad Cities International Airport’s ICAO code is KMLI.

According to IATA, airport coding started in the 1930s and used two-letter codes. By the 1940s, the number of airports was greater than the number of two-letter codes available, so the system expanded to three-letter codes. For example, Los Angeles International Airport was originally “LA” but became “LAX” in 1947.

In the 1960s, IATA began assigning location identifier codes when airlines decided a standardized process was needed to avoid confusion.

“Typically, IATA codes are based on location or the original names of the airports,” Ashleigh Davis, public relations and marketing manager at Quad Cities International Airport, told The Gazette. “For example, Chicago O’Hare is ORD because it was originally called Orchard Field.”

The land O’Hare International Airport sits on was originally home to orchards. According to Loyola University, the land was taken over by the Army Air Corps (known now as the U.S. Air Force) in June 1942. A few months later, the land was given to Douglas Aircraft Company. The company chose the name Orchard Place Airport/Douglas Field.

After World War II ended, the airport transitioned to commercial use and was renamed after Lieutenant Commander Edward O’Hare, a recipient of the Medal of Honor. O’Hare made history when he shot down five Japanese bombers and disabled a sixth during his first dogfight. O’Hare died on Nov. 26, 1943 while leading the U.S. Navy’s first nighttime fighter attack launched from an aircraft carrier.

The airport code stuck around as a nod to the land’s past.

Davis said Quad Cities International’s MLI code is a nod to Moline, Illinois. But, not all airport codes relate to the location of the airport or its history.

“Can I say exactly what CID stands for? No,” Pam Hinman, director of marketing and communications at Eastern Iowa Airport said. “Now you’re going to get all kinds of people saying they do know, but we don’t know for sure. We just know it’s always been our three-letter code.”

Can airport codes be changed?

It’s rare for an airport code change to be granted. John F. Kennedy International Airport (JFK) was originally Idlewild Airport (IDL). The airport was renamed in 1963 and the code was changed to honor the late President John F. Kennedy.

Has Sioux City tried to change its SUX airport code? Yes, multiple times.

In 1988, Sioux City petitioned the Federal Aviation Association (FAA), the United States’ civil aviation authority, to change their airport code, saying that SUX was demeaning and didn’t tell travelers or pilots which airport the code represented.

According to the March 30, 2003 edition of the Sioux City Journal, the FAA had offered the city five options — GWU, GYO, GYT, SGV and GAY. Ultimately, officials decided to retain SUX. Today, the IATA code GAY identifies Gaya International Airport in India.

In 2002, Sioux City tried again, petitioning for the code SGA in order to represent Sioux Gateway Airport. Unfortunately, SGA was already in use for Sheghnan Airport in Afghanistan. But the FAA decided that time that SUX was here to stay and denied the request to change the code.

SUX isn’t the only less-than-desirable airport code in use. Flyers traveling to Fresno, California have FAT listed on their tickets. If you’re heading to Boleshoye Savino Airport in Russia, look for the airport code PEE on your luggage tag.

Requests to change IATA airline codes can be submitted, but according to the organization’s website, “IATA cannot entertain requests for changes for improvement in marketing or branding of the airline.”

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How have airports embraced their IATA codes?

In 2007, Sioux Gateway Airport decided to embrace SUX thanks to a marketing campaign spearheaded by local businessman Dave Bernstein.

Hats and T-shirts emblazoned with “Fly SUX” became hot merchandise.

“As long as they’re talking about you, you go with it,” Bernstein told The Sioux City Journal at the time.

Hinman said that The Eastern Iowa Airport’s “Fly CID“ campaign has increased awareness of the airport.

“You want to make it simple for people to book a ticket … so you see many airports now, their marketing efforts are all about ‘fly’ and then whatever their code is,” she said. “In some instances, it becomes an identifier for a community, a region, just depending on the location.”

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Comments: bailey.cichon@thegazette.com