Hi Ken,
I'm not familiar with your Database engine, but I use input masks on my desktop DB's (AlphaFive -Dbase III).
Would setting up a 4-character "mask" (rejecting any 3-character ID) in the input field, for airport pictures uploads help with this issue. With the first character being the ICAO country Identifier??
It would require a little more homework for uploaders.
Also USA FAA ID's that are odd: like N17 or N24 may be a problem, unless one inputs a "K" in front to make it agree with the "mask".
Just an idle thought, for a possible quick fix.
John