the two M61 Vulcans were removed and replaced with one General Dynamics 25 mm (0.984 in) GAU-12/U Equalizer 5-barrel rotary cannon (while still retaining the H suffix). The improved MXU-470/As were even being proposed for lighter aircraft such as the Cessna O-2 Skymaster used by Forward Air Controllers but proved too heavy and cumbersome. A fit of two MXU-470/As was also tested on the Fairchild AU-23A Peacemaker, though the Royal Thai Air Force later elected to use another configuration with the M197 20 mm cannon. In September 2013, Dillon Aero released the DGP2300 gun pod for the M134D-H. It contains 3,000 rounds, enough ammunition to fire the minigun for a full minute. The system is entirely self-contained. So it can be mounted on any aircraft that can handle the weight, rotational torque, and recoil force () of the gun. The pod has its own battery which can be wired into the aircraft's electrical system to maintain a charge. Various iterations of the minigun have also been used in a number of armament subsystems for helicopters, with most of these subsystems being created by the United States. The first systems utilized the weapon in a forward firing role for a variety of helicopters, some of the most prominent examples being the M21 armament subsystem for the UH-1 and the M27 for the OH-6. It also formed the primary turret-mounted armament for a number of members of the Bell AH-1 Cobra family. The weapon was also used as a pintle-mounted door gun on a wide variety of transport helicopters, a role it continues to fulfill today. Users See also References Notes Sources Ballad, Jack S. Development and Employment of Fixed-Wing Gunships, 1962–1972. Washington, D.C.: Office of Air Force History, United States Air Force, 1982. Davis, Larry. Gunships: A Pictorial History of Spooky. TX: Squadron/Signal Publications, 1982. . Gervasi, Tom. Arsenal of Democracy III: America's War Machine, the Pursuit of Global Dominance. New York: Grove Press, Inc, 1984. . Gunston, Bill. The Illustrated Encyclopedia of Aircraft Armament. New York: Orion Books, 1988. . Jane's Weapon Systems, 1986–1987. Ronald T Pretty, Ed. London: Jane's Publishing Company, Ltd, 1986. . United States. Headquarters, Department of the Army. FM 1–40 Attack Helicopter Gunnery. Washington, D.C.: Headquarters, Department of the Army, 1969. External links M134 Minigun: The Modern Gatling Gun Forgotten Weapons M134 page on Dillon Aero site M134 page on Garwood Industries site M134 page on