Designed to meet the requirements of a US Navy specification issued on 6 December 1932, the XF7B-1 (Model 273) was the first all-metal cantilever low-wing monoplane single-seat fighter with a retractable undercarriage, and powered by a Pratt & Whitney SR-1340-30 engine rated at 550hp at 3050m.
The ABC Robin was a British single-seat light aircraft designed by A. A. Fletcher in 1929. It was a high-wing, single-seat monoplane of conventional taildragger configuration. The cockpit was fully enclosed, the first lightplane to be so equipped in Britain. It was designed at the request of T.A.Dennis (Managing Director) specifically to use the firm's 30–40 h.p. Scorpion engine.