Why is Key West EYW and other fun Airport Code history

H/T View from the Wing

On an idle Saturday, in between watching Star Trek: The Final Frontier and waiting to watch Notre Dame (hopefully) beat Michigan, I happened to see a post from Gary and View from the Wing on the secrets of airport codes. I thought I’d offer some additional thoughts on decrypting airport codes.

I’ve always found airport codes interesting. Growing up in West Islip, New York, we flew out of Long Island MacArthur Airport in Islip, NY (ISP). I’m not sure why it isn’t ISL, but there does appear to be an airport in Pakistan with that airport code.

A little history

When there were few airports in the early 20th century, they had two letters. Then as there became more, airports moved to three letters. These became the International Air Transport Association (IATA) codes. If you check flightaware, you might find the need to have a four letter airport code. These are International Civil Aviation Organization (ICAO) codes. For the US, it’s easy, just add “K” – so John F. Kennedy International would be KJFK.

Some rules for the IATA codes – at least in the US

I heavily relied upon a Business Insider post from 2012, but I’ve seen this information elsewhere too, so I consider it somewhat “fact checked.”

  • Some airport codes are aligned with the name of the airport, like JFK.
  • Some airports codes are based on the location, such as my previous example of Islip (ISP), Others would be Baltimore-Washington International (BWI).
  • Some airports are named after a historical figure, such as LaGuardia, named after New York Mayor Fiorello La Guardia (I think the airport was originally called Glenn H. Curtiss Airport). Washington Dulles International Airport (IAD) was named after John Foster Dulles (a Secretary of State under President Eisenhower).

Some exceptions:

  • In the US, the Navy has a hold on airport codes starting with the letter “N”, so Newark becomes EWR.
  • Again, in the US, W or K are reserved for radio stations. K for west of the Mississippi River, W for East. So for example, while you would think Key West would be KEY, it instead is EYW. Of course, if you’re talking ICAO, then Key West is still KEYW. (Thanks to reader: Essenn for the correction).
  • Q is for international telecommunications — I’m not sure I understand that one.
  • Z is reserved for special use.
  • The Canadian’s must really like the letter “Y”, so all of their airport codes start with it. I’m not entirely sure how they determine the remaining two letters — e.g. YYZ for Toronto

Some fun Jeopardy! questions

I recall a few Jeopardy! questions over the past few years. A couple examples of the answers were:

  • DAD – Da Nang International Airport, Vietnam
  • MOM – Moudjeria Airport, Mauritania


5 thoughts on “Why is Key West EYW and other fun Airport Code history

  1. Somehow my home town got FAT (Fresno Air Terminal) though it has been renamed to Fresno Yosemite International and local news channels like to say FYI of course the real code is still FAT.

    • @StammesOpfer there are worse airport codes! I do find it interesting though about news folks getting codes wrong… e.g. for Jacksonville International Airport, they call it JIA, whereas the airport code is JAX.

  2. I hope I can help clarify a few points.

    I’m sure you meant just the opposite for the radio prefix codes. For example WABC (New York), WGN (Chicago), WQAM (Miami). KGO (San Francisco), KNBC (Los Angeles). K-west, W-east.

    ICAO issues country codes. The CONUS ICAO code is K. Not to be confused with a radio station. Confusing, I agree.

    CONUS ATC radar facilities also have 3 letter id’s. CONUS ARTCC (Centers) begin with Z followed by 2 letters. Oakland center (ZOA), LA center (ZLA). Terminal radar facilities try to maintain geographic id’s, but sometimes the most logical are taken (DFW, DAL), hence D10 for Dallas TRACON. With the current crop of large TRACONs, a more regional ID is attempted; SCT – SOCAL, NCT – NORCAL (the FAA had to request release of that id from the Navy), PCT – POTOMAC. ATC Towers generally use the airport id.

    Hope this helps a little.

    • @Essenn – Thanks for your comment! Also thanks on the correction for W and K Radio prefixes – I listen to “WTOP” occasionally here in DC, but it just didn’t click for me. I’ve made the correction. I appreciate your additional information regarding CONUS ATC codes. I find the background quite interesting. Thanks again!

  3. Pingback: Weekly Travel News Roundup: 12 September 2014 - Tagging Miles

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