Northrop Alpha

The Northrop Alpha was an American single-engine, all-metal, seven-seat, low-wing monoplane used as a fast mail and passenger transport in the 1930s. John K. Northrop designed it after working on the Lockheed Vega, with design work done at the Avion Corporation, which in 1929 became the Northrop Aircraft Corporation of Burbank, California. It combined wing fillets researched at the Guggenheim Aeronautical Laboratory with a multicellular stressed-skin wing of Northrop's own design, and it was the first commercial aircraft to use rubber deicer boots on the wing and tail leading edges. It first flew in 1930 and 17 were built. Transcontinental and Western Air flew it from 1931, three served the US military as C-19 VIP transports, and the third Alpha built is preserved at the Smithsonian National Air and Space Museum.