If someone asked you for Dayton International Airport’s airport code, would you answer ‘DAY’ or something else? The correct answer is DAY but how did we get this code and why do airports have them at all?
Why is it DAY and not DIA?
Dayton International Airport’s location code is DAY for the name of the city. People often assume Dayton’s code is DIA, but this is the location code for Doha International Airport in Qatar. To understand how our airport came to be identified as DAY, it helps to know a little more about airport codes.
A Brief History of Airport Codes
In the 1930s, pilots started using a two-letter city identification system created by the National Weather Service to refer to airports. By the 40s, there were so many airports being established that they expanded the system by adopting an additional letter. Some cities added an ‘X’ to get to three letters, like LAX in Los Angeles and PDX in Portland. In the 1960s, the International Air Transport Association (IATA) standardized the three-letter codes and maintain a database of location codes to this day. You can search location codes here. The IATA is the global trade association of airlines and their codes are the ones you’ll find on your luggage tags and boarding passes.
There is another organization that maintains a list of airport codes – the International Civil Aviation Organization (ICAO). These four-letter codes are used by air traffic control (Dayton’s is KDAY). The ICAO is a specialized agency of the United Nations created in 1944 to set standards and practices that align national regulation for aviation safety and security, as well as other concerns.
Fun fact: ICAO has the first off-planet location code. When NASA’s Ingenuity helicopter took off from Wright Brothers Field located in the Jezero Crater on Mars in April 2021, ICAO designated the location code JZRO.
How Airport Codes are Created
Airport codes come from all sorts of things such as the name of the city, the name of the airport, or even a notable person from that town’s history. ‘DAY’ represents the first three letters of Dayton, like Hartfield-Jackson Atlanta International Airport’s ‘ATL.’ ‘PHL’ is a perfect fit for Philadelphia International Airport in the same way ‘LGA’ makes sense for LaGuardia Airport in New York.
Some airport codes require a little more explanation, however. For instance, ‘ORD’ is the location code for Chicago O’Hare International Airport, having originally been a military airport called Orchard Field Airport in the 1940s. Orlando International Airport is coded ‘MCO’ for its original name of McCoy Air Force Base. ‘PIE’ was a logical choice for what was originally called the Pinellas International Airport (renamed St. Pete-Clearwater International Airport).
Here are the codes for other airports in the Dayton area:
- Wright-Patterson Air Force Base – FFO
- Dayton-Wright Brothers Airport – MGY
Airport codes may have come about in a sort of haphazard way, but today they tell a story of the history of commercial flight as well as the local history of each airport.