how airport come up with their abbreviations

Question

I think they’re called, airport codes? But, how do airports determine what theirs is? It seems like there isn’t an clear pattern to different airports abbreviations. (EX: Denver’s airport code is DEN, San Francisco’s is SFO, Baltimore’s is BWI)

In: Other

Answer 1

It depends, some are descriptive tradition like National (DCA, literally DC Airport) or Hobby (HOU for Houston). Some are designed to be similarly descriptive on a new airport, like Dulles (IAD, literally meaning International Airport Dulles) or Houston Bush (IAH, for the same reason as IAD). BWI also falls into this category.

Some codes bear little relevance to their airports namesake; such as Carroll County Regional in Maryland, which bears the identifier DMW; or York, Pennsylvania bearing the identifier THV.

Now, those are FAA codes, and all FAA airport codes that are letters only drop the leading K from the international (ICAO) identification (ie BWI’s full identifier is KBWI). Some FAA codes don’t have the leading K with 3 letters. W00, Freeway and W05, Gettysburg Pennsylvania are examples of this. When you have one of those airports, the lack of the K indicates it doesn’t have weather on field.

Now, the US is one of the few countries where the airport identifier when you book matches the airport’s actual identifier (Canada is another, but England is not, and Alaska and Hawaii are exceptions). Many countries have 2 letter prefixes. For example, Benito Juarez airport in Mexico City is MEX when booking, but the actual airport identifier is MMMX with MM being the prefix for Mexico. Nassau will show up as NAS when booking, its identifier is MYNN with MY being the prefix for the Bahamas. Heathrow is LHR when booking but its identifier is EGLL, EG being the prefix for the UK. In these cases the identifier you see is determined by the International Air Transport Association (IATA), and is used for convenience over the ICAO.

TLDR: it’s determined by either the local aviation administration, such as the FAA or EASA, or by the International Civil Aviation Organization (ICAO). The codes you frequently see are actually IATA codes and don’t identify the airport for the purposes of a flight plan, only booking. In some countries, like the US and Canada, the IATA and ICAO codes tend to match.