Ok, hear me out. I have noticed that the pilot of a little bird is more often shot out of the helicopter then when the heli is damaged by enemy fire. I expect to be shot at and maybe even be hit in the front of such a lightly armored heli but I have noticed it seems I more often get shot out of a pristine helicopter then I take damage.
I have a theory on this. I assume that the AI uses the same targeting for ground as it does for air targets (the same level of accuracy and leading). The truth is that it is very hard to hit a pilot in a chopper. The AI is not being penalized for the lack of distance estimators (no ground clutter or detail to help estimate the range to an aircraft, no hit impacts in the dirt to readjust the shot for distance). This is what makes it so hard for a person playing arma to do this, but the AI seems to not be bothered by it.
I also theorize that the AI continues to target the pilot instead of the helicopter as a whole resulting in even more hits on the pilot as opposed to the helicopter.
I propose that the AI be given an additional penalty to aim for aircraft tha are airborne. I also propose (if it is true that is) that the AI not target the pilot specifically but instead he targets the airframe as a whole.
The goal is to get more situations where the pilot has to deal with a damaged aircraft and isn't just killed out right.

DasClark

ps - this ignores dedicated AA systems. They seem to target the aircraft as a whole as do missiles.
pss - This mostly applies to front facing situations. If you always have your back to the enemy, you will take engine and ATRQ damage first (as the AI is still aiming at you but the chopper is now in the way).