Your choice to fly a cannon plane or a MG plane just like every other person, so it is 100% with out a doubt fair.
If you pepper a plane with MG's and do not strike anything critical, the plane would not fly a lot differently.
But under your premis is it fair that an MG kills a pilot with 1 bullet , and a cannon completely removes 1/2 the pilots body , but still only gets 1 kill?
HiTech
Well yeah, you can only kill a plane once, doesn't matter how much you mutilate the plane, it's 0 or 1, killed or not.
This is a programming assumption on my part but let me know if I am incorrect. Every single plane part has, say 100 damage points. When each part is reduced to zero, the plane part fails. Maybe 1 beebee reduces a plane part by 2 hit points where as a 30 mm tater will reduce that plane part by 100 hit points. I don't believe it is fair that a 50 cal plane can say, reduce 15 plane components by 15 damage points for a total of 225 hit points causing no actual damage to the plane under the current damage modeling system. Another plane can then come in and actually kill the air plane by shooting off the left wing for a total of the 125 remaining hit points but since the the sprayer acrued 225 hit points, he gets credit. (Please don't pay too much attention to my numbers as they are all hypothetical, and obviously inaccurate but only used to illustrate my point)
I'm not saying a pilot should get credit 100% of the time for simply shooting off the critical component but imo there should be some balance. Perhaps a bonus should be credited to the pilot that gets the kill shot and that bonus is added to his total damage points. I might be off base here as I am making an assumption as how the damage model works, but this seems a little more fair to me.
Say you had Pilot A shoot off an elevator, an aileron, oil leak, pilot wound, and then Pilot B shoots off the left wing. I don't think Pilot B should get the kill just because he landed the fatal shot, but should get a small damage bonus for doing so. I'm assuming it could be coded to where Pilot A would still get the credit for inflicting so much damage prior. Balance would be key.