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McFly
08-01-2007, 09:59 AM
This is not exactly GPS specific but since it causes me grief on my Lowrance 1000, I am posting here.

Why do some airport identifiers need a 'K' prefix when searching for an airport by identifier? For example, my home airport identifier is 'CIC' on the Sacremento sectional and facility guide but if I search my GPS for 'CIC', it will not find it. You must enter 'KCIC'. This can and has doubled my heads down time.

I initially thought it might be related to size of the airport or VOR on the field but that does not seem to be the case.

Lowrance if you are listening, a useful feature would be to add a prompt along the lines of "Did you mean KCIC?" when "CIC" is entered.

Mike S
08-01-2007, 10:13 AM
Somewhere back in the dark recesses of my poor old brain, I seem to remember it has to do with international stuff. All U.S. is "K"

az_gila
08-01-2007, 10:18 AM
Check your GPS setup... you might be able to set it up so that a "K" is assumed as the first letter of an airport designator if only 3 letters are used...

My old Apollo GX-55 does this.... saves a little time entering stuff... :)

gil in Tucson

ddurakovich
08-01-2007, 10:28 AM
'K' is one of the internation prefixes assigned to the US. All radio stations in the US begin with either a W, A, N, or K.

Civil aircraft begin with the letter 'N'.

The 'K' when used with an airport code is actually a weather station designator. Hence, small airports without an 'official' weather service feed do not have the letter 'K'.

GPS's use it because an airport identifier is not necessarily unique to the US, so the 'K' indicates that it is a US location. Also applies to radio navigation identifiers.

Be careful if you're GPS does not require the 'K'.... could be confusing when the direct to shows the next waypoint at 6719 nautical miles!

dan
08-01-2007, 10:34 AM
Basic rule of thumb...if the identifier has 3 letters, use the K prefix. If it has any numbers in it, leave the K off.

Jetj01
08-01-2007, 10:40 AM
If you enter your airport ID without the 'K' and your GPS requires the K for specific distinction, you will be entering the identifier for a NAVAID. Example: Here at Sheppard AFB, TX the field identifier is KSPS, however the associated VORTAC is SPS which is located 5 miles west of the airport. Granted you're close to the field but if the WX is hazy or you really need it to find the airport (anyone land at Twin Oaks in San Antonio lately? Without GPS I'd still be looking for it even on a clear day!) you probably won't.

So, the K tells the GPS that you are indeed looking for the airport and not the navaid.

And to add to an earlier post, some airports only have 3 alpha numeric ID but they are, as noted, without WX info and usually have letter(s) and numbers. As has happened at Kickapoo airport her in Wichita Falls, it recently got WX reporting and their ID changed from a 3 alpha numeric ID to a K prefix + 3.

Tailwinds

mrreddick
08-01-2007, 10:44 AM
I fly into many airports that have a K that don't have an ASOS or AWOS on the field. What I have seen in the last few years is that when an airport, let's say Graham, TX, gets an ASOS. Their designator was E15. When the ASOS or AWOS was activated it became KRPH.
Now, in my Lowrance 2000c, in I say find KADM it's going to take me to Ardmore Municipal located a few miles east of town. If I punch in ADM it's going to put me right over the top of the Ardmore VOR, closer to the north of town and a good ways from the airport.
So, know your unit and be careful out there. First and foremost, read the operator's manual. Lowrance explains it very clearly in the instructions.

az_gila
08-01-2007, 10:48 AM
If you enter your airport ID without the 'K' and your GPS requires the K for specific distinction, you will be entering the identifier for a NAVAID. Example: Here at Sheppard AFB, TX the field identifier is KSPS, however the associated VORTAC is SPS which is located 5 miles west of the airport. Granted you're close to the field but if the WX is hazy or you really need it to find the airport (anyone land at Twin Oaks in San Antonio lately? Without GPS I'd still be looking for it even on a clear day!) you probably won't.

So, the K tells the GPS that you are indeed looking for the airport and not the navaid.
.......
Tailwinds

Depends on the GPS... with the Apollo, a knob selects "airport" and then the "K" is not needed. This prevents the navaid from being selected.

Check your specific GPS setup...

gil in Tucson

Brian130
08-01-2007, 11:14 AM
Notwithstanding the GPS issues, here's the actual reasons for the K or lack thereof:

http://www.faa.gov/airports_airtraffic/air_traffic/publications/atpubs/LID/CH1.htm

Bottom line: they get a K if they have (1) manned ATC, (2) a navaid on the field, (3) scheduled air carrier or military airlift service, or (4) they're an airport of customs entry. And, (5) certain weather reporting stations.

a. Three-letter identifiers are assigned as radio call signs to aeronautical navigation aids; to airports with a manned air traffic control facility or navigational aid within airport boundary; to airports that receive scheduled route air carrier or military airlift service, and to airports designated by the U.S. Customs Service as Airports of Entry. Some of these identifiers are assigned to certain aviation weather reporting stations.c. Most one-number, two-letter identifiers have been assigned to aviation weather reporting and observation stations and special-use locations. Some of these identifiers may be assigned to public-use landing facilities within the United States and its jurisdictions, which do not meet the requirements for identifiers in the three-letter series. In this identifier series, the number is always in the first position of the three-character combination.

d. Most one-letter, two-number identifiers are assigned to public-use landing facilities within the United States and its jurisdictions, which do not meet the requirements for identifiers in the three-letter series. Some of these identifiers are also assigned to aviation weather reporting stations.

e. Two-letter, two-number identifiers are assigned to private-use landing facilities in the United States and its jurisdictions which do not meet the requirements for three-character assignments. They are keyed by the two-letter Post Office or supplemental abbreviation (listed below) of the state with which they are associated. The two letter code appears in the first two, middle, or last two positions of the four character code.
1-4-1 Use of Location Identifiers: An international location indicator is a four-letter code used in international telecommunications. The location indicator for airports in the contiguous United States is the three-letter identifier preceded by "K". For other non-contiguous United States airports, the following two letter prefix will be used...

Bill Dicus
08-01-2007, 05:44 PM
All US airports I've encountered with an alpha ident begin with K and Garmin's literature says this is so. If the airport's identifier begains with a letter, the K should be added to the beginning of the ident. All airports (private or public) whose identifier begins with a number do not require or have the K. I don't know where this is spelled out in the regs but it's consistent with everything I've found in Loran and GPS databases and at all airports where we've landed or visited. Hope this helps. Bill

rvator51
08-01-2007, 07:48 PM
All US airports I've encountered with an alpha ident begin with K and Garmin's literature says this is so. If the airport's identifier begains with a letter, the K should be added to the beginning of the ident. All airports (private or public) whose identifier begins with a number do not require or have the K. I don't know where this is spelled out in the regs but it's consistent with everything I've found in Loran and GPS databases and at all airports where we've landed or visited. Hope this helps. BillI think this is mostly true, but there are exceptions such as K81 - Miami County Airport, Paola, KS where I stopped for fuel on the way back from Oshkosh.

Mel
08-01-2007, 08:07 PM
Airports with a "3 letter" identifier get the "K" to separate them from VORs that have the same identifier. Most GPSs require the "K". Some don't.

Brambo
08-01-2007, 08:21 PM
Now for the BIG question: Why is the US = "K"? Canada is "C", Mexico is "M"
and Europe is "E". So why K for the US?

Bill Rambo

lucaberta
08-02-2007, 04:28 PM
Now for the BIG question: Why is the US = "K"? Canada is "C", Mexico is "M"
and Europe is "E". So why K for the US?
nope. Europe is not E, that is Northern Europe. We Southern Europeans have L as the area prefix.

In most countries the first letter is the area, and the second is the country. My country, Italy, is LI, L for South Europe, I for Italy. Belgium is E for North Europe, and B for Belgium.

The last two letters are completely left to the discretion of the country.

Canada and the US, being so huge and having so many airports, have a single letter with the final three ones to be used to identify airports and/or weather stations.

Mexico is MM, Cuba is MU...

Ciao, Luca

nucleus
08-02-2007, 05:24 PM
All US airports I've encountered with an alpha ident begin with K and Garmin's literature says this is so. If the airport's identifier begains with a letter, the K should be added to the beginning of the ident. All airports (private or public) whose identifier begins with a number do not require or have the K. I don't know where this is spelled out in the regs but it's consistent with everything I've found in Loran and GPS databases and at all airports where we've landed or visited. Hope this helps. Bill


Not true! I fly out of 9S5, no K involved, on my garmin, apollo or otherwise.

Hans

Mel
08-02-2007, 05:40 PM
Not true! I fly out of 9S5, no K involved, on my garmin, apollo or otherwise.

Hans
9S5 does not begin with a letter. Only airports with 3 letter identifiers get the "K"

gmcjetpilot
08-02-2007, 11:49 PM
Now for the BIG question: Why is the US = "K"? Canada is "C", Mexico is "M"
and Europe is "E". So why K for the US?

Bill RamboIATA (eye at uh) is what airlines use and are three letter; ICAO (eye kay oh) 4 letter ID's are for weather stations, air control centers. "K" was assigned and don't know for sure why K. A - America or U - USA may have caused some confusion? Australia is Y. Some one said K is the 13th letter for the 13 original colonies, but unfortunately my fingers and toes say it letter 14. (edit oops thanks Tobin Basford (below), I have extra toes, 11, any way 13 does not work either) M for Mexico, so M was not available? Probably arbitrary.

Note, Hawaii and Alaska start with P for Pacific. International ICAO airport ID trivia below.

ICAO and IATA ID's are totally different some times. For example Naples Italy is NAP in IATA, however in ICAO its LIRN and it makes more sense, at least if you fly international flights. L - Lower Europe, I - Italy, R - Rome ATC, N - Naples. You can probably now guess Paris ICAO ID: L - low euro, F - france, P - paris atc, G - Gaulle (Charles de Gaulle Airport), LFPG is De Gaulle France, ICAO is (CDG).

ONE MORE! IATA (LHR) London Heathrow Airport London, England. E - upper europe, G - great britian, L - london control, L - london, so ICAO - EGLL. You can figure out the big airports, but when there are several in one city or don't know the ATC regions it gets a tricky.

Adding K to our 3-letter US ID's to get ICAO is not so bad. We do not follow the 4-letter convention. Hope we never change, but their system works when you fly international and makes sense.

Now why "N" numbers on US planes. There are some theories but its a mystery. Here is a great article on the history of N-numbers:
http://www.aahs-online.org/articles/N-number.htm

Here are the worlds first letter ID.
http://upload.wikimedia.org/wikipedia/en/thumb/c/c3/ICAO-FirstLetter.png/800px-ICAO-FirstLetter.png

tobinbasford
08-03-2007, 07:26 AM
Some one said K is the 13th letter for the 13 original colonies, but unfortunately my fingers and toes say it letter 14. M for Mexico, so M was not available?

Uh??? What alphabet are you using George??

a b c d e f g h i j k
1 2 3 4 5 6 7 8 9 10 11

Ironflight
08-03-2007, 08:08 AM
Uh??? What alphabet are you using George??


Maybe it's not his alphabet Tobin - maybe we don't know how many fingers and toes he has...could George be an alien?!? :p :eek:

jmartinez443
08-03-2007, 11:25 AM
This is not exactly GPS specific but since it causes me grief on my Lowrance 1000, I am posting here.

Why do some airport identifiers need a 'K' prefix when searching for an airport by identifier? For example, my home airport identifier is 'CIC' on the Sacremento sectional and facility guide but if I search my GPS for 'CIC', it will not find it. You must enter 'KCIC'. This can and has doubled my heads down time.

I initially thought it might be related to size of the airport or VOR on the field but that does not seem to be the case.

Lowrance if you are listening, a useful feature would be to add a prompt along the lines of "Did you mean KCIC?" when "CIC" is entered.
I think you are confusing CIC (the colocated VOR) with KCIC (the airport on which the VOR is located) on your sectional. Chico IS KCIC regardless.

McFly
08-03-2007, 03:45 PM
I think you are confusing CIC (the colocated VOR) with KCIC (the airport on which the VOR is located) on your sectional. Chico IS KCIC regardless.

Negative.

Looking at my slightly out of date 2006 sectional both the airport and the VOR are identified as CIC. The Sacremento identifier is SMF, yada yada yada. If the "K" was included as part of the identifier on the sectional, I would not have made the origional post :p Blue skies

gmcjetpilot
08-03-2007, 03:48 PM
Uh??? What alphabet are you using George??

a b c d e f g h i j k
1 2 3 4 5 6 7 8 9 10 11Ohoops back to first grade, thanks. Any way 13 colonies is a bogus reason. 11 is what? And yes I've got extra toes and fingers, I knew swimming around three mile island was a bad idea, :D