@rollin :

regarding that :


"give helicopter/planes the ability to "see" how big buildings are and fly around or over them if they are too high"



Have you made any progress in that ? After taking a look into some fit files, I found that most if not all object have the same settings in the (Bound) part. X, Y and Z is all set to 20. Have you tried changing those values ?

Either MS didn't get it working, or was simply to lazy to edit different bounding boxes per model