How airport codes are assigned and the history of ORD

HostYou know that little sticky tag the gate agent wraps around your suitcase handle? It has those three big letters on it that tell the world where your bag is supposed to go. It’s like a secret language for travel, but have you ever looked at those letters and wondered why they were picked? Like, if you fly into Chicago, your bag gets a tag that says O-R-D, even though there isn’t a single D in the name of the city.

GuestIt's funny because those tags are basically a map of history that most of us just don't see anymore. Back in the thirties, when flying was still pretty new, pilots didn’t actually have their own naming system for airports. They just borrowed whatever the weather service was using at the time. Back then, weather stations only used two letters to identify a city. So, if you were flying to Los Angeles, the code was just L-A.

HostBut only having two letters seems like it would cause problems pretty fast. There are only so many ways you can combine two letters before you run out of names.

GuestThat’s exactly what happened. By the forties, the whole flying business just exploded. With only two letters, you can only make about six hundred different codes. That might sound like a lot, but when every small town started building an airfield, they ran out of names almost immediately. So, the groups in charge of travel had to jump up to a three-letter system. That one extra letter was a huge deal because it meant they could make over seventeen thousand different codes. It gave every little landing strip its own unique tag.

HostSo when that happened, did the big airports just get to pick a new letter to stick on the end of their old two-letter code?

GuestWell, they didn't really pick anything special. A lot of the famous airports that were already around just used the letter X as a filler to take up that third spot. They didn’t need a new meaning, they just needed a third letter so the computers and charts would work. That's why we have L-A-X in Los Angeles, or P-D-X in Portland. The X doesn’t mean anything at all. It’s just a placeholder.

HostOkay, that makes sense for the ones that just added an X. But Chicago is still the weird one. Where do you even get O-R-D from a name like O’Hare?

GuestThat one is like a ghost from the past. Before that airport was a huge hub, the site was a big factory during World War Two where they built transport planes. The factory was right next to a tiny farming community called Orchard Place. Because of that, the airfield was officially named Orchard Field. So, O-R-D is just a shortened version of Orchard.

HostBut they changed the name of the airport over seventy years ago to honor a pilot. Why on earth wouldn't they just change the code to something that matches the new name?

GuestIt sounds easy, but it’s actually a total mess if you try to change it. These codes are baked into every flight map, every pilot manual, and every tracking system on the planet. If you change a code for a major city, you have to update every single piece of paper and every bit of software in the world so pilots don’t get confused. It costs way too much money and it's too much of a safety risk just to make a name match up. In the world of flying, the names of the buildings change, but the codes are almost forever.

HostIt feels kind of strange, though. We’re all flying around using nicknames for places that don’t even exist anymore.

GuestIt’s like that everywhere once you start looking. If you go to Orlando, the code is M-C-O. It doesn't stand for Orlando; it stands for McCoy Air Force Base, which used to be on that land. In Nashville, the code is B-N-A because the airport used to be called Berry Field. Even down in New Orleans, they use M-S-Y, which stands for a guy named Moisant who ran a stock yard there. You're literally flying to a cow pasture from a hundred years ago.

HostThat's wild. Does every country follow these same weird rules? I feel like every time I see a flight to Canada, the code starts with the letter Y.

GuestThat’s a special case. It goes back to the old radio systems. Back then, if a weather station was at the same spot as the airport, they used a Y to show that it was there. Eventually, Canada just decided to make that the standard for all their big airports. It became their own national way of doing things.

HostSo who actually gets to decide who gets which letters? Is there some main office that hands them out?

GuestThere’s a group called the International Air Transport Association that acts as the gatekeeper. They treat those three-letter codes like a limited supply. They almost never let anyone reuse a code once it’s been retired. If an airport closes down, they usually lock the code for a few years just to make sure there’s no mix-up with bags or flight paths. It’s a very strict system because it’s the primary way baggage systems and ticket bookings talk to each other.

GuestYour boarding pass is basically a list of ghosts, naming forgotten military bases and old farmers' fields that are still kept alive by the flight system.

HostThat little sticky tag on the suitcase handle is more than just a way to get a bag home; it’s a piece of history that follows us every time we leave the ground.