Never more than 676 Airlines?
 

I’ve been curious about this for a while. What happens to and/or who allocates the 2-letter airline codes. Have any two letter codes been re-allocated? I’m not good at civil aviation history but the recent demise of SR in leu of LX got me thinking. I’m sure that Pan-Am had their 2-letter code as well as TWA. And with so many low cost airlines having come and gone, 26 squared couldn’t be the limit, could it?

Some airlines have numbers in their 2-letter code, I guess that creates another several hundred possibilities. Doesn't JetBlue's code contain a number?

Air Canada's "Zip" discount airline is code 3J.

Some airlines code-share, too. That's code-sharing, Jim, but not as we (normally) know it.

A friend pointed out a week or two back that the new Norwegian service run by Norwegian Air Shuttle shares the same code as Air Djibouti. Go to Travelocity and search for Oslo-Tromso flights, and see for yourself.

Looks like it's 1,296 possible codes. As others have noted, numbers are used. JetBlue is 6B or B6. Some others include the late Canada 3000 (2T) and Roots Air (6J).

There's also some recycling. Example: The old British Caledonia code (BR) is being used by Eva Air.

There is also sharing by regional airlines. Example: WS is used by 3 minor airlines in addition to West Jet.

Pop quiz:

What airline (which still exists) used to use the code AL?

What airline (which still exists) used to be TS?

USAirways, when it was Allegheny.

Aloha Airlines, when it was Trans-Pacific.

[This message has been edited by Efrem (edited 01-16-2003).]

Yes they do get re-allocated. Originally, an australian domestic airline called TAA (Trans Australian Airways) was allocated TN. This airline then changed its name to Australian Airlines and continued using TN until it was bought from the Australian government by Qantas. Qantas retained the registered company name of Australian Airlines but not the TN flight designator which has since been allocted to another airline (can't remember who).

Now that Qantas has re-launched the Australian Airlines name as a low-cost international service operator, it cannot use the TN flight designator or the original Australia Airlines.

With almost as many mergers and closures as new airlines, there is plenty of scope for re-use. But it can confuse some on-line reservation systems.

Codes have been deliberately swapped by agreement between airlines, too, in the recent past. Eurowings persuaded East-West of Australia to give up "EW" for Eurowings' use. I can't now remember what form the "persuasion" took ...

Efrem:

Actually, US Airways continued to use the AL code for quite a while (at least a few years) after it dropped the Allegheny name.

The 2 character codes are allocated by IATA, the airlines' international trade body. They are used for reservations, timetables, airport arrivals boards, etc. As noted above, the codes are pretty much used up but the addition of numbers in recent years has given more combinations. The memorable codes for the established carriers(eg BA for British AW) are all gone; this leads to eg Air 2000 getting DP.

There are also 3 character codes allocated by ICAO (International Civil Aviation Organisation). These are used for flight planning, ATC, etc. British Airways are BAW for example; Air 2000 are AMM (think about it!). They used to be the same 2 character codes as IATA, but when the codes ran out ICAO had to change first (they have many more operators to deal with).

IATA have meant for years to change to the same 3-character codes but the established airlines are resisting this because of the costs of reprogramming all their computer systems (any IT person will understand what this would imply in terms of cost and/or liability to bugs) for something that will give them no benefit; it will only benefit new entrants.

ICAO 3-character codes are all unique. IATA 2-character codes are reused where airlines do not operate in the same area (generally interpreted as the same continent).

There is a comparable split with airport codes. IATA does 3-character codes for these whereas ICAO does 4-character codes. So London Heathrow is LHR or EGLL dependent on system. The ICAO code is subdivided; E = Europe, G = Great Britain, and LL = 2 character code for airports within Britain.

US ICAO codes all start with K, and then the last 3 characters are the IATA ones. Thus KJFK and KMIA for New York JFK and Miami.

Canadian ICAO codes all start with CY, followed by a 2-character code. So it's CYYZ for Toronto and CYVR for Vancouver. Look familiar? The Canadians, like the Americans, base the IATA airport code on the ICAO one by chopping off the first letter, but because of the different format this leads to all the Canadian codes starting with Y. And that's how Toronto got to be YYZ. Actually, there's a bit more to it than that. Toronto was allocated CYTO, but when the current international airport (Pearson) opened subsequently, and a new code was needed, all the more appropriate 2-character codes within Canada had gone, so they used YZ for the last 2 letters. YVR for Vancouver is more understandable using these rules.

[This message has been edited by WHBM (edited 01-18-2003).]

Regarding the number of available codes:

(1) It seems at least one character must be a letter.

(2) Any of the 26 letters may be used, but the numerals 0 and 1 are apparently NOT used, so as to avoid confusion with I and O.

So the number of available 2-character codes is:
(34 ^ 2) - (8 ^ 2) = 1156 - 64 = 1092.

(edited to get disable smilies in place of exponent signs)

[This message has been edited by LastClass (edited 01-17-2003).]

That's correct. I think US was used by the U.S.A.F. for M.A.C. flights. AL had to get a suitable code for the U.S.A.F. to rade for the US code.

Are there any airline codes where both digits are numbers? (e.g., "33") If that's not allowed, then there are fewer than 1092 combinations.

I've always wondered why Southwest is WN. Anyone know? I imagine this is an easy question for the experts here.

cnk

That was condition (1) in my post above. I subtracted out the 64 because that's how many codes involving the eight available digits would be forbidden.

Who kNows?