Bien-Hoa Air Base, Republic of South Viet-Nam, fall of 1972.  Marine Air Group 12, composed of two Marine fixed-wing, jet attack aircraft squadrons are flying, the A-4 Skyhawk, a light, extremely fast and maneuverable attack dive bomber, in support of South Vietnamese ground troops around the Saigon tactical area of operations, and to the west towards Cambodia.  In addition, U.S. Marine helicopters augmenting the South Vietnamese Air Force, fly from the deck of the USS Tripoli, steaming off the coast.  Pilots must now deal with the sophisticated Russian supplied, hand-held SA-7 anti-aircraft weapon operated by experienced North Vietnamese gun crews who have been defending their homeland in the north.  The north vietnamese fighters have been fighting for seven long years and now clearly have the momentum as they push towards their ultimate objective, Saigon.