twoeagles is correct, the inner doors sag when the engine is off due to loss of hydraulic pressure. Same thing happens on most big aircraft (747, C-17, ect). Look at them after engine shut down, and you will see the elevators and ailerons drooping, just because of no hydraulic pressure. But once it is on, they will spring into the nutureal position, just like the gear doors on the P-51 closing after engine start.