Three letter strings
Consider all possible three letter combinations of the English alphabet. From AAA to ZZZ. There are 26 x 26 x 26 = 17,576 of them in all, or 626 per letter.
Some of these are valid English words - you could use them in a game of Scrabble. For example, ACE, BAT, ZAG etc.
IATA also assigns three letter codes to airports. You know, the ones you see on your boarding passes and baggage tags. Like AMS for Schiphol, Amsterdam. Quite a few of the possible 17,576 three letter strings are also IATA codes1.
For a comprehensive and entertaining look at these three letter IATA airport codes, I’d highly recommend watching this video by CGP Grey:
Some IATA codes are also valid English words. For example, YEA (Edmonton, Alberta, Canada), YES (Yasuj Airport, Iran).
And some English words are not yet2 IATA codes. For example, AYE, YEP, YUP.
The venn diagram of three letter strings, IATA airport codes and words
I was interested in exploring the entire space of these three letter strings visually, especially in context of 3 letter IATA codes. So I built a little web app that lets you see this information for each English letter.
It was fun to visually see how M and S are completely packed, while Q and X are still wide open.
The strings are sorted alphabetically by default. So if you are looking at, say the letter A, the first row goes from AAA to AAZ, the next from ABA to ABZ and so on till AZA to AZZ.
Three letter strings from AAA to AZZ, sorted alphabetically
You can also sort the list by type. This will cluster IATA codes that are valid words, IATA codes, valid English words and non-words together3.
Three letter strings from AAA to AZZ, sorted by type
If you are on a desktop browser, you can hover over each IATA code to see the airport’s name and location in a tooltip. On a mobile, you can tap to do the same.
If you really want to have some fun though, you can say ridiculous things in sentences of IATA codes that are valid words.
YES, MAD4 SIR CAN EAT ANY BUS, CAR AND VAN.
And for those of you that are a bit more ambitious, you could buy an island, start an airport and apply to IATA for words that haven’t been assigned to an airport yet. Looks like GOD is still available. Anyone?
p.s. Here is a plot showing the utilisation of three letter strings from A to Z:
A plot showing different categories of three letter strings
p.p.s. On an altogether higher intellectual plane - looking for words in amino acid sequence of a real protein.
Based on publicly available data on Wikipedia, as of today (11 Aug 2023), about 9083 (51%) of the three letter strings are also valid IATA codes.↩︎
Though YET is - Edson Airport, Alberta, Canada.↩︎
This reminded me of a defrag.exe from DOS days. Apparently, there is Twitch stream where you can watch a disk defragment all day.↩︎
The Indian city of Madras (now Chennai), got MAA. And there is another Madras - in Oregon, United States. Their municipal airport is MDJ.↩︎