This is a very good idea, though I don't think it should cost perks, it should be free, but maybe take longer depending on how damaged (ei,Engine 40+ secs,Fuel, oil or radaitor 30+ secs flaps,ailerons,rudders and elevators 15-20+ secs).
Players need to be encouraged to land, instead of just crashing, but currently landing just takes allotta time and you cant get anything repaired.
Also I liked the idea some1 had about a ".move ammo" command idea, where you could move ammo from 1 gun pos to another in bombers (if same cal) with a delay of like 20 secs for 25 rounds.