is it possible to detect when an airborn building lands?

You can detect when a building is landed versus airborne yes.

Just unflag the air or ground elevations in your location and you can know by whether it is or isn't in the location.

Just keep in mind that when it lifts off, it moves up one square, and vice versa when it lands... it's a bit annoying for what i'm working on right now > >...

and of course unflagging ground or air is just for detection.... you can still center that loc on things that aren't its "element." But you won't detect them with it.

yes to your question, thats all he wanted to know.

No, unfortunately not. While landing, buildings cannot be detected in any location.

You could, however, detect absence in combination with deaths.
Always center on the building, and when it's not in that location anymore and the player still has 0 deaths of that building, you know
a) where he is
b) that he's trying to land somewhere
Now you could for example kill all his buildings of that type (hope you only have 1!) and recreate it in a buildable location. Even if you create it airborne you need buildable terrain underneath or you will get an unplaceable error.

If you tell us more about why you need to detect it we could possibly tell you better workarounds for your problem, if that's needed.

actually, disabling the locations detection abilities for air works perfectly, the air building will spawn, and when it lands, another unit will be given. thanks for the assistance