In 1931 Northrop built the prototype of an all-metal low-wing sporting monoplane X/NC12214, the Beta (ATC 2-401), a two-seater with a 119kW Menasco Buccaneer inline engine.
Designed by Don Berlin, a dorsal fairing and canopied cockpit were later added. An advertisement in Dec 1932 Aero Digest quoted a $5,000 sale price.
It was converted to single-seat high-speed mailplane configuration in 1933 and fitted with a 300 hp / 224kW Wright Whirlwind radial engine, in which form it became the first aircraft of such power to exceed 200mph / 322km/h. Reported speeds up to 212 mph were reached.
Damaged in a landing accident on 16 January 1933, it was rebuilt by Stearman for planned testing of various wing flaps, but destroyed in a crash on 5 June 1934.
Beta 3D
Engine: 300hp P&W Wasp Jr
Wing span: 32’0
Seats: 1
All Aero 