It's simple really. A timer.
bare with me.
On initial use of a weapon a timer begins. This same weapon cannot be selected again from the hangar until the timer expires. For this purpose planes and vehicles are weapons.
For planes: Take off starts the timer.
For example. I launch a Fw190a5. If its timer lasts 1/4 of 100% fuel burn time. If I die in it in the next 8 or so minutes, I cannot reup in a Fw190a5 until timer expires (I can however up in anything else that doesn't have an unexpired timer). If I live past the 8 minutes, then die, I can just reup in the same plane.
For bombs/rockets: Timer starts when dropped or fired.
For example:
1k bomb=10min
Once a bomb is dropped the timer starts and another bomb of similar poundage cannot be selected until timer has expired. So you either wait or go with a lesser bomb load.
May be just forget about the plane part. I like to vulch too.
Please take into consideration that I am a self pronounced tard and everything I say is pretty dumb.
F.