A small idea:
How about we implement a small feature in case 'keep the plane alive' is introduced? Tragic and sad in humanistic aspect(sincerely), but watching combat films portraying a plane go down with dead pilots is really cool.
If pilot kill happens, there will be some 'a pilot's final action' instantly kicking it so it prevents planes flying almost indefinately.
In the case of fighters, the dead pilot would cause a 'slump over effect'. The plane will nose down and begin to spin, just as the action portrayed in WWII footages. When a pilot dies in a level flight, the plane immediately begins a slow nose down in a shallow dive and start to spin. When a pilot dies in a upward maneuver, all stick inputs stop(since the body would lean back, not slump over on a stick) and the plane will continue upwards until it stalls(plane will not fall back into control automatically, as in some cases), and then it would tumble down. When a pilot dies in a downwards maneuver, the plane will go into a near vertical downwards spinning dive.
In the case of bombers, if the pilot dies, the buff begin start move in a shallow dive that slowly rolls to one side.
I don't think we really need to keep the planes up in a 'realistic' manner once the pilot is dead. The 'visually cool' is enough in this case.
Fighter pilots might have a chance to escape by faking 'pilot death'.. meaning: kills would not be awarded until the plane augers and is destroyed. The attacker will have no idea if the pilot is dead or not. But, once the pilot is dead, the kill judgement stops function, and no matter how many shots are fired into the dead plane by someone else, it would give the kill to the attacker who finally knocked out the pilot. Sort of a 'reserved kill', in case of pilot deaths.
Planes that the pilot bailed from would react just the same. No change in icons, but the attacker would be required to 'check his kill'.