Get In into MH-9 or AH-9 doesn't matter (might be reproducible on other vehicles)!
While the Animation is starting to play (character getting in) Open the MAP.
MAP WILL BLINK (I Assume it blinks when "GET IN" animation stops playing and your character takes a SITTING POSITION).
Close the MAP.
Your character will be sitting inside the HELI with a DEAD (Unconscious) POSE.