Why Are Airports Sometimes Missing in Output
Actually, they aren't really missing -- they have just had the
airport attribute removed (in .DAT or .STX output files) or
converted to style "Unknown" (in .CUP) output files. Note
that, depending on user settings, SeeYou or SeeYou Mobile may not
display points that are set to the Unknown style.
WHAT IS GOING ON?
The system checks each point that is listed as an airport in input
turnpoint files to make sure it is listed in the FAA's airport
database. In cases where the FAA airport ID is not
explicitly given in the file, the system tries to find one at the
same or nearby location with a similar name. If this check
fails, the airport attribute is removed, and/or the point is set
to style "Unknown" as described above.
The purpose of this check is to filter closed airports from output
files so that pilots won't rely on them anymore. It is a safety
feature. Unfortunately, airport closures are very common events.
Note: the system will log these changes in the log
file. It is a great idea
to always check the log file to look for unexpected changes.
WHAT SHOULD YOU DO?
Assuming you don't really want the airport attribute to change,
there are several possible workarounds:
- If you just want to do a file conversion without the system
updating any of your data, select the "Do not add or update
airports in the output files" option from the drop-down list,
right under the box where you entered the turnpoint file name.
The system will leave your airports alone. This is the
option you would select if you were, for example, converting a
file for an area outside the US.
- If the problem is that the airport has stale name or position
information that is causing a problem in the database lookup,
edit your turnpoint file manually and correct the name or
- If your input file is a .CUP file, you can change the style to
"Outlanding Place". In .STX or .DAT input files, you can
remove the "A" attribute and replace it with the "L" attribute.
- Finally, if you really wish to retain the airport attribute on
a point that does not exist in the FAA database, there is a way
to force that. For an input file in CUP format, edit the
comment for the point such that it begins with "PRI-A:" (for a
private airport) or "PUB-A" for a public airport. This
amounts to telling the system that the point is an airport, but
does not have an FAA identifier code. See the explanation
of comment formats in Comments in
.CUP Output Files for more information. In STX
files, you can set the value in the "ICAO" comment to an
asterisk for the same effect.
One other hint: if you are updating an old turnpoint file,
remember to set bounding information for airport addition.
You can either set a bounding circle by choosing a center airport
and a radius, or you can have the system automatically compute a
bounding polygon that includes all the input file
turnpoints. Choose the appropriate option from the drop-down
list right underneath the box where you entered the turnpoint
(Press BACK to continue)