Airport Identifiers

[brianreid]

Did I miss something? Recently I tried to input my destination airport by going to Map>Info>Airport and then tried to dial in the identifier for my destination (DUJ). My Skyview could not find an airport with that designation and rolled over to VORs and then intersections. It would not go back to searching for airports. The only way out was to completely exit and start again. Eventually, I discovered that I needed to add a K to the identifier. When I did that the Skyview found KDUJ right away. Note there is no DUJ vor.  I decided that the easiest thing to do was always add the K to airports. So on the way home I added a K to my home base P15. Skyview could NOT find it. Put in just the P15 and there it was. So, three questions:
   1. What is the rationale as to when to add the K to airport identifiers and how can I remember it?
    2. Why when I have asked Info to find Airports does the system roll over to another type?
    3. How do I get back to searching for airports without completely exiting?

I can't find anything on these issue in any of the installation or usage manuals. Thanks for you help.

 

[RVDan]

'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.

With respect to the databases, K is used when the airport identifier is all letters. A three letter identifier without the K is a navaid. If the identifier has any numbers in it
, the K doesn't seem to be used

Hope it helps.

 

[dynonsupport]

There is no perfect method to know if a airport has a "K" as the first letter. The identifier for Sea-Tac in Seattle is KSEA. It isn't "SEA" with a "K" in front of it. The "K" is the USA's country code in the ICAO structure, so airports that have a "K" are ones that are ICAO airports. Note that ICAO is totally different than IATA, which is what airlines use. London Heathrow is EGLL in ICAO and LHR in IATA. General Aviation GPS units use ICAO. The advantage of ICAO is that you can't accidentally fly to the wrong country. There is no other KSEA in the world, but there might be 7 "SEA" airports, each in a different country.

If there is a general rule, it's that a class D or larger airport will have a "K," but there are many exceptions to this, especially in the other direction.

You can't search for just airports. INFO is info for any identifier that we know about, be it a user waypoint, an airport, an IFR fix, an NDB, or a VOR. This is pretty much the way all aviation GPS units work. You weren't "stuck" looking for things other than an airport. It's just that if you had DUJ in the first three characters, it's only going to match things starting with DUJ, and KDUJ doesn't match. You can use the knob to move the cursor back, so if you had moved over to the D and changed it to a K you would be in business. The SkyView system does PREFER airports if one matches what you have started to enter, but if there was no airport in your database starting with DUJ, there was nothing for it to prefer. This, if you enter KD, it will find KDUJ quickly because that is an airport, even if there is a KDB NDB.

You have a lot of options to look up an airport that doesn't require you to know the ID:

1) The best is to move the cursor over to the airport you want on the map. When on the map screen, use the knob to move the map around. This will allow you to see the ident right on the map so you know what it's called. You can also press NRST at this point and it will be the first on the NRST list. Then you can press Direct to or INFO as needed.

2) You can move to the line below the IDENT and spin in the English name for the airport. This works a lot, bit it also has issues. Around here we have "Paine Field" but legally this is "Snohomish County" so you need to enter that, not Paine. This is the name on the sectional though, so if you still have one of those in the plane you can look at that.

3) You can go the line below the airport name and enter a city name like "Seattle" and get the list of Seattle airports.

 

[dynonsupport]

With a quick glance at the database, RVDan's suggestion that airports without numbers are KXXX and airports with have no K appears to be pretty solid.

 

[RVDan]

Here it is right from the FAA website


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 [ch65533]K[ch65533]. For other non-contiguous United States airports, the following two letter prefix will be used:

Notice it says "three LETTER identifer" gets the prefix.

Good question. It finally drove me to find the conclusive answer after years of guessing myself.

 

[brianreid]

Thanks for your help and clarifications.