By 1966 the U.S. Army's CH-47A Chinook helicopter passed a milestone of 50,000 flight hours, of which 14,000 were accumulated in combat in Vietnam. The Chinook entered the Army's inventory in April 1963. The missions of this twin-turbine tandem rotor helicopter include the rapid air transport of forty-four fully equipped troops, artillery, ammunition and crews, and fuel to resupply vehicles and other aircraft in forward areas.