You want a plane to crash and not bouch?
I dont know how to do that, what I will tell you is how to make a plane crash and not explode.
The easiest way is to just remove all of is ammo and fuel. This way the plane will crash but not explode.
If you want the plane to remain fairly intact you need to save it at the last minute; make a trigger with a condition and set the planes health to full, and the position to you where you want it. I prefer a little trigger that when the plane crashes it gets repaired and then stopped.
Condition ; Getpos PlaneName Select 2 < 3
Activation ; PlaneName SetDammage 0; PlaneName Setpos (Getpos PlaneName)