I never specified because it's just plain common sense.
Would you shoot at a moving or stopping helicopter with a grenade?
EDIT: The soldiers begin running away from the beacons to cover, taking pot shots at the soldiers as they leave. The soldiers are quickly replaced by an Mi-24 helicopter, the doors slide open and .50 calibre machine guns open fire.
Suddenly, anti air guns quickly gun down the helicopters, causing them to explode mid air, sending shrapnel downward as well as large, still-intact bits and pieces.