Hi roswell, hi all
We've all been there I'm afraid when we start with FSSC and Airport. Most of the macros that come with both progs are old (FS98??) and many give the problem you've found. They are great when you are learning but when you begin to make 'serious' scenery you have to discard quite a few and either search and download replacements or make your own using eg EOD. I've found even some 3rd party objects like radio towers have flickering bases that you just can't get rid of by playing around with alts.
I think I know the one and you'll probably find that the hangar with the problem isn't even texturised - it just has solid colours for the sides and roof which emphasises the 'old' point.
So what can you do? Not a lot apart from what I've said. You still seem to be a bit of a novice with the scenery design so my advice is (with respect and the best possible intentions) use this stuff to learn. Don't expect 'professional' results just yet. As you become more proficient and critical of your own work you will make demands on yourself and learn how to create your own stuff that doesn't have the problems you are talking about.
Sorry I can't be more helpful to give you a quick fix - but that's scenery design for you
