I just thought this might work...
Ok so....bombers are AI UNLESS someone pilots them, right? (I hope)
Well, let the bombers take off as AI then let someone have the option of getting in them along the way, so the enemy can still down them at any time, no one has to waste time climbing, AND you still get to gun and bomb and what not. Maybe even have the option of joining an AI plane as tail gunner only and let it fly and bomb, or as pilot only and, (hey can the AI tail gun?), if the AI CAN tail gun then join as only a bombardier/pilot or whatnot.
there's my two cents