English: In order to provide additional close air support for highly mobile U.S. Army units in the 1970's, the USAF planned to develop the A-X aircraft. This attack fighter was expected to be relatively simple and rugged, and it was designed for the specific purpose of providing ground forces with close air support, to replace the A-1 Skyraider and A-37 Dragonfly which were pressed into this role to meet Southeast Asia requirements. The A-X was to be a twin-engine, turboprop aircraft with the ability to operate from short, forward area airstrips. USAF concept emphasized operational flexibility with a wide range of trade-offs available between fuel load and ordnance. They expected the A-X to be able to take off from a short forward runway—one very close to the forward edge of the battle area—with a large ordnance payload, fly out on a short radius mission, and loiter for hours in the combat area. Where a longer runway is available, the aircraft should be able to carry more than double the ordnance payload on a longer radius mission, and still loiter for hours. Ease of maintenance, reliable communications tailored to the combat environment, and simple, low-cost navigational and armament equipment was to be part of this aircraft. A very significant feature of the A-X was to be its unusually high level of survivability in the face of concentrated enemy antiaircraft weapons, achieved through such design features as extensive fuel system protection, dual manual flight controls, and heavy armor. Development was scheduled to begin in fiscal year 1970.