Tested. Here are the results:
Helicopters cannot be blown up by AA missiles while in the air. At all. Even 2-3 missiles has apparently no chance of killing anyone inside nor of causing an explosion.
The good news is: You can safely land when hit with AA, so can the AI. Even if you are at 500m it is really easy to autorotate down (I had no training it doing so and I did it on my first try)
Note that the heli *is* destroyed, all components are red. But the rotor is not actually destroyed and the occupants seem unharmed even by 2 missiles.
New bug: The littlebird variants rotor disappears but continues to fly as if it is still there.
While we technically got what we want I think what most Arma players are looking for is unpredictability. Right now if you are hit, you WILL survive. You just wont have a heli anymore.
Development suggestion for astaroth: Make the explosion radius on the AA missiles smaller, right now it seems to encompass the whole helicopter and destroy all components. If the radius were smaller, and the damage lower (slightly), then the actual place where the missile hits would affect what happens following. If it hits the cockpit, the pilots are killed, if it hits the tail rotor, just that is blow apart, if it hits the side, it will likely kill passengers and damage or destroy the engine. Another major concern is that of auto rotation. How am I to fear having my engine blown apart if I, a totally novice pilot, can survive a fall from 500m? All I had to do was tilt the rotor back so that my forward and down speed turned the rotors fasters, before hitting the ground I actually started to ascend again.