So why do we have both 3 and 4 letter codes? And why do airlines have 2 or sometimes 3?

As far as I understand 3 letter airport codes are IATA (International Air Transport Association) codes. These are primarily used by airlines, airports and travel agents for route planning purposes. Most airlines are IATA members. For this reason, some ports and railway stations also have IATA codes. 4 letter airport codes are ICAO (International Civil Aviation Organization) codes. The ICAO is responsible for standardising and co-ordinating civil aviation and almost all civilian flying on a global scale, which includes ensuring national civil aviation authorities comply with their standards for beacon markers, VORs, ATC, accident investigation. In essence, the ICAO regulates bodies such as the CAA and FAA.

In terms of airline codes, 2 digit codes (e.g. BA, AF, DP, U2, ZB) are IATA codes. These are alpha-numeric. ICAO airline codes are 3 digit alphabetical codes (BAW, AFR, FCA, EZY, MON). From a passenger perspective, airlines generally choose whichever code they think passengers will remember; however, most flight plans would use the 3 digit ICAO codes.

For a list of codes, see here.

As Tenthije says, 3 letter IATA codes are used for connecting modes of transport, such as seaports and railway stations. Changing them would affect almost every online travel agents’ booking system and logistics system. ICAO codes make more sense to those who understand the coding system, but in many countries often bear little significance to the name of the airport, VOR, beacon etc…

Excellent report and great photos. Very enjoyable reading.

http://www.thomascook.co.uk has US for £303 or KLM/Martinair (LCY-AMS-MCO) for £323.

Agreed. This should allow Druk Air to launch new routes, from what I understand.

Great shots. I can’t wait to return to MAN in November!! 🙂

Great pictures