1. Place an MH-9 on the map and a player unit next to it.
2. In game, get into the heli as a pilot and fly a few feet off the ground, then land leaving the engine on.
3. Immediately get out of the heli, press I to open the gear screen for the heli and put your gun inside. BOOM!
Steps can be reproduced with the AH-9 except in this case the Heli does not blow up, except it renders it damaged and unusable.