Sounds simple enough. It may have something to do with a vehicle that heavy sitting stationary and turning the wheel (the force of the tire on the floor of the aircraft) but I don't know either, just talking out my ass. Seems like some kind of chock like device that could lock into the rings (or whatever is in the floor) or the side rails of the cargo compartment would be simple and adequate enough. But I'm no load. Again, just talking out my ass.