Built by the Ling-Temco-Vought for the US Air Force, the A-7D Corsair II was more powerful than its US Navy Corsair II predecessor. The A-7D even provided infantry support for the US Army during the Vietnam War. Although its speed hampered helicopter escort missions, its ease of flying made up for this minor shortcoming. On top of being was faster than its Navy counterpart, the US Air Force Corsair was also equipped with a new heads-up tactical and computerized navigation/weapons delivery system with radar. Armed with larger M61 rotary cannon in place of the Navy's two single-barreled 20-mm cannon, the USAF A-7D was completely refitted for close-in-air-to-ground support for troops in the fields of South Vietnam. Economical to fly, the aircraft's heads-up weapons delivery system, increased power, and better fuel consumption reduced the overall cost-per-target and this meant fewer missed targets on more sorties. For the record, the A-7DCorsair II had the lowest losses of any other US fighter in Southeast Asia, only 6 lost planes out of 12,928 missions.