In 1929 John Northrop designed and developed a two-seat single-engine aircraft which was basically a flying wing with two slim booms supporting the tail unit. The aircraft, built by Northrop's newly formed Avion Corporation (later the Northrop Aircraft Corporation) was powered by a 67kW
Menasco engine, initially driving a pusher propeller but modified later to tractor configuration.
Experience with this early aircraft was stored away for a decade until Northrop could pursue his all-wing concept, but in 1940 the Northrop N-1M flew with two 48kW Lycoming engines buried in a thick wing to drive pusher propellers. The N-1M was a true all-wing design and its low drag gave improved acceleration in both dive and glide; it also enabled the aircraft to use significantly less power on take-off than conventional aircraft of similar size and weight. Early tests found few problems, the main one being engine cooling, but this was solved by the installation of 89kW Franklin engines with three-bladed propellers and improved baffles. The N-1M has survived in the US National Air and Space Museum.
