ICAO Airport Codes

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sherryfly
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ICAO Airport Codes

Post by sherryfly » Sun Mar 24, 2019 10:14 pm

Hello!

Sorry for the slightly dumb question. I have always been curious why all airports in Canada generally begin with the letter C, and American airports with K, Asian airports with O... and so on. Who designates which letter will apply to the area? And what does it stand for? Do the letters have any meaning? I’ve attempted to google this and have not found any answers. Perhaps one of you wonderful people could help!
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ahramin
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Re: ICAO Airport Codes

Post by ahramin » Sun Mar 24, 2019 10:55 pm

There are no dumb questions but I know the answers to a few of those
sherryfly wrote:
Sun Mar 24, 2019 10:14 pm
ICAO Airport Codes

Who designates which letter will apply to the area?
ICAO
sherryfly wrote:
Sun Mar 24, 2019 10:14 pm
Do the letters have any meaning?
C means Canada
K means USA
M means central america
E means England & Ireland
L means Europe

That's all I can think of off the top of my head. The first letter is often region and second letter country, so EI is Ireland and EG is Great Britain. MM is Mexico and MP is Panama.

One I've always found strange is Sechelt. ICAO CAP3 IATA YHS, but ICAO CYHS is Saugeen. I guess you can't have an IATA code with numbers and they needed one for sched service at some point?
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Re: ICAO Airport Codes

Post by nbinont » Sun Mar 24, 2019 10:56 pm

ICAO airport codes are designated by a combination of the ICAO (International Civil Aviation Organization) and the country. ICAO provides the prefix (for example 'CY' for Canada, or 'EG' for the UK), then the country can assign the remainder of the 4 letters to their airports. Thus you get CYYZ or EGLL.

The official list is published as ICAO Document 7910: Location Indicators. Unfortunately it is not free.

A short summary of the prefixes is free: http://www.b737mrg.net/downloads/ICAO_country_codes.pdf
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Adam Oke
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Re: ICAO Airport Codes

Post by Adam Oke » Sun Mar 24, 2019 11:16 pm

Back in the day airport were coded with a 2 National Weather Service system. Example Ottawa was OW and Los Angeles was LA. Eventually as aviation grew, this became unmanageable and turned into a 3 letter IATA system used by major carriers around the world allowing for addition permutations. As aviation grew and additional airports were being built, they then found a need to designate airports with weather stations with a code.

Eventually Canada simply added Yes (Y) or No (N) to denote the original weather service system. YOW Ottawa, NZ3 Chatham-Kent. In the states they used X as the code for weather stations, for example LAX.

Further down the road, eventually C was added for Canada and K was added for the states. Among other countries.

U was also used for co-located nav aids and W was also used to denote without weather.

ICAO is used by ATC and civilian use, where as IATA is used by major air carriers and for tagging purposes. For example Jardines del Rey Airport/Cayo Coco is CCC (IATA) or MUCC (ICAO) with the M being Central America. U meaning co-located nav aid.

Airports that don't make sense now, made sense back in the day. For example KMCO (Orlando) was originally McCoy Air Force Base. As for CYHS it was originally Hanover Saugeen (HS) under NWS, then YHS to denote weather, then CYHS as ICAO. I believe it never was an IATA code as that is for air transport used by major carriers around the world.
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Last edited by Adam Oke on Mon Mar 25, 2019 12:51 pm, edited 1 time in total.
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sherryfly
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Re: ICAO Airport Codes

Post by sherryfly » Mon Mar 25, 2019 10:33 am

Thank you so much, everybody, for the responses! One more quesion.. why "K" for the USA? Wouldn't a "U" or "A" be more fitting? Does anyone know why the letter K was chosen specifically?
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Re: ICAO Airport Codes

Post by lhalliday » Mon Mar 25, 2019 12:02 pm

The U.S. uses K because they had lots of radio stations whose callsigns started with K. The rationale for the initial assignment of K and W for U.S. radio stations is not recorded. They also have N, plus AAA-ALZ.

Since airplanes are self-contained radio stations their registrations are radio callsigns for their country. Hence N for the U.S. and CF/CG for Canada.

...laura
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Re: ICAO Airport Codes

Post by ant_321 » Mon Mar 25, 2019 12:28 pm

Adam Oke wrote:
Sun Mar 24, 2019 11:16 pm
Back in the day airport were coded with a 2 National Weather Service system. Example Ottawa was OW and Los Angeles was LA. Eventually as aviation grew, this became unmanageable and turned into a 3 letter IATA system used by major carriers around the world allowing for addition permutations. Air aviation grew and additional airports were being built, they then found a need to designate airports with weather stations with a code.

Eventually Canada simply added Yes (Y) or No (N) to denote the original weather service system. YOW Ottawa, NZ3 Chatham-Kent. In the states they used X as the code for weather stations, for example LAX.

Further down the road, eventually C was added for Canada and K was added for the states. Among other countries.

U was also used for co-located nav aids and W was also used to denote without weather.

ICAO is used by ATC and civilian use, where as IATA is used by major air carriers and for tagging purposes. For example Jardines del Rey Airport/Cayo Coco is CCC (IATA) or MUCC (ICAO) with the M being Central America. U meaning co-located nav aid.

Airports that don't make sense now, made sense back in the day. For example KMCO (Orlando) was originally McCoy Air Force Base. As for CYHS it was originally Hanover Saugeen (HS) under NWS, then YHS to denote weather, then CYHS as ICAO. I believe it never was an IATA code as that is for air transport used by major carriers around the world.
Interesting. Any idea if there is any significance for the C or D in some smaller Canadian airstrips? Like CCD2 or CDY3?
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Re: ICAO Airport Codes

Post by Adam Oke » Mon Mar 25, 2019 12:43 pm

ant_321 wrote:
Mon Mar 25, 2019 12:28 pm
Interesting. Any idea if there is any significance for the C or D in some smaller Canadian airstrips? Like CCD2 or CDY3?
Sorry, I don't know. That's about all the nerd-ing I've got. :lol:
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Re: ICAO Airport Codes

Post by PilotDAR » Mon Mar 25, 2019 7:33 pm

E means England & Ireland
L means Europe
In Europe, "E" is northern, and "L" is southern, though I'm not sure exactly how it divides. "E" also extends into Scandinavia. The second letter in the code may be the nation, though other letters appear for other use airports/heliports, so the rule seems to vary a little.
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Re: ICAO Airport Codes

Post by ahramin » Tue Mar 26, 2019 6:25 am

Whoops, good point PilotDAR. I didn't think of totally obvious ones like EHAM and EDDF.
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Re: ICAO Airport Codes

Post by W5 » Wed Mar 27, 2019 3:58 pm

Regarding radio stations:
https://www.rd.com/culture/radio-stations-k-w/

Obviously Canada was assigned '' C ''
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Re: ICAO Airport Codes

Post by C-GKNT » Mon Apr 01, 2019 7:13 pm

Adam Oke wrote:
Mon Mar 25, 2019 12:43 pm
ant_321 wrote:
Mon Mar 25, 2019 12:28 pm
Interesting. Any idea if there is any significance for the C or D in some smaller Canadian airstrips? Like CCD2 or CDY3?
Sorry, I don't know. That's about all the nerd-ing I've got. :lol:
Nav Canada assigns whatever is unused and reasonably close. For example I thought "C"hong "R"esidence should be CCR# (where # was the next unused number) but got CRE5 for "C"hong "RE"sidence. They appear to be somewhat flexible and base on my experience would probably agree to any request that is unassigned.

Glenn
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