The Northrop A-17, also known as the Northrop Model 8, a development of the Northrop Gamma 2F model, was a two-seat, single-engine, monoplane, attack bomber built in 1935 by the Northrop Corporation for the United States Army Air Corps. When in British Commonwealth service during World War II, the A-17 was called Nomad. The Northrop Gamma 2F was an attack bomber derivative of the Northrop Gamma transport aircraft, developed in parallel with the Northrop Gamma 2C, designated the YA-13 and XA-16. The Gamma 2F had a revised tail, cockpit canopy and wing flaps compared with the Gamma 2C, and was fitted with new semi-retractable landing gear. It was delivered to the United States Army Air Corps for tests on 6 October 1934, and after modifications which included fitting with a conventional fixed landing gear, was accepted by the Air Corps. A total of 110 aircraft were ordered as the A-17 in 1935. The resulting A-17 was equipped with perforated flaps, and had a fixed landing gear with partial fairings. It was fitted with an internal fuselage bomb bay, that carried fragmentation bombs, and external bomb racks. Northrop developed a new landing gear, this time completely retractable, producing the A-17A variant. This version was again purchased by the Army Air Corps, who placed orders for 129 aircraft. By the time these were delivered, the Northrop Corporation had been taken over by Douglas Aircraft Company, with export models being known as the Douglas Model 8. For operational history in 10 countries and details of 11 variants, click here.