Well, I don't think any B-29 pilots would actually launch without flaps, or with only 3 of 4 engines operating, so the idea may need a bit of refinement

Perhaps set a minimum level of "resource points" for each plane (B-29 is more expensive than a Bf-109F). If you bring back your B-29 with, say, 75 of its 100 resource points "intact," you get back 75 points. If you bring it in on two engines, 1 1/2 wings, no gear, and then chew it up on landing, maybe its "salvage value" is only 10 points.
That 75 (or 10) points goes back into your "account," from which you "purchase" the perk planes. After all, you didn't really "buy" the planes you flew, but if you pranged too many, your CO sure wasn't going to trust you with the only prototype Dora on the field, was he?

--jedi
[This message has been edited by jedi (edited 12-27-2000).]