Useless trivia about IATA airport codes

Continuing the discussion from Trolls R Us Resurrections:

I was going to post this in the above-mentioned Pit thread where there was some discussion of three-letter IATA airport codes, but it seemed like an excessive hijack even for the Pit. This subject has been discussed before but this is a bit more detail.

Some random trivia, because airport codes interest me … so this is offered for those who have an affinity for completely useless information … :wink:

ORD may not immediately evoke Chicago but it’s a major hub so its airport code is generally familiar. I used to think the code came from the name O’Hare Field, but as someone correctly pointed out earlier, when the IATA code was first assigned in the 1940s it was still called Orchard Field.

In the US and around the world, most (not all) IATA codes have some mnemonic significance. When it has no similarity to the city name it’s often derived from the airport name, as in ORD for Chicago, LHR for London Heathrow, or CDG for Paris (Charles DeGualle airport). Sometimes it gets mangled by restrictions, like the US Navy trying (not altogether successfully) to get dibs on all codes starting with “N”, hence Newark becoming EWR. Other times the codes reflect city combinations – DFW for Dallas-Ft. Worth, MSP for Minneapolis St. Paul.

The similarity to city names or well-known airport names makes the use of airport codes fairly natural especially to seasoned travelers, as in “I’m flying from ATL to LAX”. “LAX” is probably the most recognizable airport code in the world. It’s a little different in Canada, though. It’s hard to say “I’m flying from YYZ to YUL” without sounding like you’re describing an interplanetary voyage in a galaxy far, far away.

The way these codes came about goes back to the 1920s and 30s. Canada has since standardized on “Y” as the first letter of all airport codes, although a few smaller ones start with “Z”. Originally, though, the story goes that old two-letter airport codes back in the day were preceded by “Y” (“Yes”) if the airport had a weather station, which usually also meant a radio beacon. If not, the code was preceded by “W” (“Without”). The “W” codes have since fallen out of use.

As for the other two letters, I haven’t positively been able to confirm this mystery but it seems that they were usually sourced from the original two-letter codes of either the airport weather station and/or nearby railway stations. Thus “YZ” was the code for the Malton station, near which Pearson International Airport was built, and now bears the IATA code YYZ. A few airports have semi-mnemonic codes (Vancouver is YVR) but most do not.

To add to the fun, YUM is not in Canada at all but refers to Yuma, Arizona; YVA is Moroni, the capital of Comoros off the east coast of Africa, and YVD is Yeva in Papua New Guinea. Bastards stole our codes!

Louisville is SDF because it used to be named “Standiford Field.” I remember it because I associate it with Robotech (“SDF-1”).

I still have my boarding pass for a flight from Pensacola to Charlotte. That is, PNS-CLT.

I’m so grown-up.

As I mentioned in the other thread, I’ve taken a train out of LAX several times.

At least you didn’t have it framed! *

* You didn’t, right?

P.S.- A boarding pass from Pensacola to Varginha, Brazil would be even more fraught!

Sort of? I can remember that it starts with “O” and then two more letters that don’t look like “O’Hare”, but I can never remember what those two letters are. LAX, though, is iconic enough that I remember.

I irrationally thought the X in LAX stood for “international”. Not sure why. Turns out X is just a place filler to comply with the 3 letter standard.

The code for Orange County Airport (officially John Wayne, but I’m old and liberal) is SNA for Santa Ana. Santa Ana is two cities over and isn’t even the largest in the county. But it is the county seat.

I (and I assume others) pronounce ORD as a one syllable word, making it easier to remember. Everybody spells out LAX and most other codes.

I remember it because we used to go shopping at Old Orchard Shopping Center, named for the same orchards.

In the 1980s when Guatamala was in civil war, someone pointed out before I went skiing how easy it would be for a baggage handler to misread the tag for Geneva (GVA) and instrad send my luggage Guatamala City (GUA)

I bet there’s a lot of screeching on a flight from Yokohama Airport (YOK) to Russia’s Okra Airport (OHH) and then on to Ontario Municipal Airport (ONO).


Dulles International airport is IAD. You’d think it would be DIA, and it used to be DIA. The story I’ve heard is that DIA was easily confused with DCA which was and is the code for Reagan National Airport, (for District of Columbia airport).

Happily, Baltimore Washington International is BWI.

More bastards stealing Canadian airport codes! And curse you, too, Yola, Nigeria!

Not entirely unprecedented as Houston International Airport is IAH (technically George W Bush Intercontinental Airport) and Niagara Falls (NY) International is IAG. Not sure why they chose “G”, but currently “IAN” is taken, though it’s a small airport in Arkansas.

There’s also PHX for Phoenix and PDX for Portland OR. The original names of those three airports didn’t have the X. They are old enough that (some?) airports only had two character designators. When things were more standardized they just added the X to the end of those.

Edit: Maybe PHX was originally PX.

My 1987 flight to Costa Rica made a stop at GUA. The edges of the runway were still scattered with the remains of WWII era fighter aircraft.

A similar example is Mirabel International, a relatively new airport built way outside of Montreal that was supposed to be the new international airport while the old one at Dorval (YUL) served domestic traffic. This never happened because Mirabel was so far out of the city that it was very unpopular, so now it just basically handles cargo.

But this airport was new and there was no old weather station or anything else to base its code on. So my speculation is that they just started with the mandatory “Y”, added “M” for “Mirabel”, and then were stuck because both the natural mnemonics YML and YMB were already taken. So Mirabel became YMX.

There are actually quite a few Canadian airport codes that have just a single letter as a mnemonic nod to the name it represents – YYC for Calgary, YQR for Regina, YEG for Edmonton, YHZ for Halifax, YYB for North Bay, and many others.

And then you have the ICAO codes, which may or may not have anything in common with the IATA ones.


The IATA codes are generally used in more “customer facing” applications than the ICAO ones (booking, timetables, baggage handling).

Yes, I was going to mention that but left it out for the sake of brevity.

AFAIK, the ICAO codes for US and Canadian airports are all the same as the IATA codes, preceded by one of the assigned ITU country letters. For Canada, it’s “C”. For the US, it’s “K”, for the same reason that western broadcast station call letters start with “K”, eastern ones with “W” (another assigned letter) and all US aircraft registrations start with “N” (yet a third ITU-assigned letter).

The IATA codes are generally much more familiar to travelers for the reasons you state. And yes, outside of the US and Canada the ICAO codes have no relationship to the IATA codes.

ATL for Hartsfield Jackson International Airport is well-known, I think, not just because it’s the world’s busiest airport, and “ATL” is an obvious abbreviation for “Atlanta”, but also because the rappers, deejays, and producers of Atlanta’s vibrant musi scene have adopted it as a common nickname for the city. As in the phrase “reppin’ the ATL”.

I would personally love to see a flight from Sioux City, Iowa to Dickinson, North Dakota (SUX-DIK)

On a different note, when Panama City, Florida built a new airport in the late aughts, all the logical three letter codes were already taken. So they went with the seemingly random ECP, but they claim it stands for “everyone can party”.