Northrop YA-9

The Northrop YA-9 was a prototype attack aircraft built for the United States Air Force A-X program, which sought a low-cost close air support aircraft with long loiter time, low-speed maneuverability, heavy cannon firepower and extreme survivability after ground-attack losses in Vietnam. Northrop and Fairchild Republic were selected on 18 December 1970 to build the YA-9A and YA-10A prototypes. The A-9 was a shoulder-wing monoplane of all-riveted aluminum with twin turbofans in nacelles under the wing roots, using the 7,200 lbf Lycoming YF102 rather than the General Electric TF34, a large cruciform stabilizer and split ailerons that doubled as airbrakes. The YA-9 first flew on 30 May 1972 and the second prototype on 23 August. The Air Force passed it over for the YA-10, which became the A-10 Thunderbolt II.