I don't think this mod is a good idea. Why? My main reason is that in multiplayer, players can fly and land some pretty darn badly damaged aircraft without bailing. I myself for example have landed a B-25 with one elevator and rudder completely sheared off, and the other rudder sheared off, just leaving the one elevator untouched. I also had a dead engine.
Another example was recently when I was flying a B-29, and I lost both my alerons and rudder (means no steering!) and I was able to land it by adjusting the throttle differencial between the engines. And another was when I've glided home with a dead engine from over 50K away (and a lot of altitude).
There are so many possibilities on how to survive normally critical damage, and to be able to land it. It would require a ton of coding to fit in all the posibilities, and in the end, chances are people will find ways to make it back anyway, and the game gives an incorrect 'shot down' status.
I prefer the current system, since you only get the points if the plane crashes completely, or ditches in a field. That way, there's no mistake.
On the point of belly or crash landing - Sure, you may have effectively disabled it, but planes have survived belly or crash landings to be repaired and brought back to service. Usually, the pilots survive, and in some cases, even the plane. So technically, it's not an actual kill. The B-25 "Little Patches" survived ten crash landings in its career, enough to actually permanently bend the structure. But, did it stop her? Nope. It just kept on flying...with a 6* aleron and *8 rudder trim.
Saying that forcing a plane down (but not destroying it) is a kill is like saying your slapshots toward the goal should all count as goals, even if the goalie catches them. It doesn't make sense! The game itself says "Aircraft Destroyed", not "Aircraft Forced Down". If you want to be really technical, guns, engines, fuel tanks, control surfaces, even entire wings can be replaced and bolted on to replaced damaged or destroyed parts of it. An actual airframe loss is when it should be considered destroyed - or its a smoking crater in the ground.
