if anyone's curious to know why the airplanes are immediately deleted when they are destroyed it's because of two things:
1) when their engines have been damaged to some level then the unit is flagged for deletion
2) if unit is flagged for deletion and it's a unit type of airplane then immediately remove from game
Thus now that I figured out why they were removed I have a patch to fix it
New version of patcher coming here soon so you all can test this out. It's not complete - it will just currently stop the airplanes from being immediately removed from the game when they are destroyed
