Northrop Alpha

The Northrop Alpha was an American single-engine, all-metal, seven-seat, low-wing monoplane fast mail/passenger transport aircraft used in the 1930s. Design work was done at the Avion Corporation, which in 1929, became the Northrop Aircraft Corporation based in Burbank, California.

Drawing on his experience with the Lockheed Vega, John K. Northrop designed an advanced mail/passenger transport aircraft. In addition to all-metal construction, the new Alpha benefitted from two revolutionary aerodynamic advancements: wing fillets researched at the Guggenheim Aeronautical Laboratory at the California Institute of Technology, and a multicellular stressed-skin wing of Northrop's own design which was later successfully used on Douglas DC-2 and Douglas DC-3. In addition, the Alpha was the first commercial aircraft to use rubber deicer boots on wing and empennage leading edges which, in conjunction with state-of-the-art radio navigation equipment, gave it day or night, all-weather capability. The aircraft first flew in 1930, with a total of 17 built.

The Alpha entered service with Transcontinental & Western Air (future TWA) making its inaugural flight on April 20, 1931. The trip from San Francisco to New York required 13 stops and took just over 23 hours. TWA operated 14 aircraft until 1935, flying routes with stops in San Francisco, California; Winslow, Arizona; Albuquerque, New Mexico; Amarillo, Texas; Wichita, Kansas; Kansas City, Missouri; St. Louis, Missouri; Terre Haute, Indiana; Indianapolis, Indiana; Columbus, Ohio; Pittsburgh, Pennsylvania; Philadelphia, Pennsylvania; and New York. Three Alphas were operated by the US military as C-19 VIP transports until 1939.

The third Alpha built, NC11Y, was re-acquired by TWA in 1975, and is preserved at the Smithsonian National Air and Space Museum.

The Northrop Alpha represents a notable point of transition in modern airline design, for it combined features of the past and of the future in a very utilitarian package. The passengers were enclosed in a comfortable cabin, while the pilot remained exposed--and sensitive--to the elements. The modern aspects of the Alpha--an all-metal structure, semimonocoque fuselage, and cantilever wing--were partially offset by the use of a single engine and fixed gear.

John K. Northrop, who had previously designed the Lockheed Vega, conceived of the Alpha as a means of proving his ideas for quantity production of an all-metal airplane with the machine tools existing in the early 1930s. Always pioneering new ideas and new techniques, Northrop became one of the most influential men in the aviation industry.

The Alpha was designed to be a high-performance plane that could carry mail and passengers out of small fields. The plane was attractive to airlines because of its comparatively high top speed (177 mph for later models) and high reliability. The latter was due in large part to the use of the dependable air-cooled Pratt and Whitney Wasp engine of 420 horsepower.

With the advent of the larger twin-engine Boeing and Douglas transports, the Northrop Alphas were relegated to carrying freight, serving well in this capacity. The Alpha could fly from coast to coast in twenty-three hours, carrying such commodities as freshly cut gardenias, silk worms, medical serums, and auto parts. Stops were made at Winslow (Arizona), Albuquerque, Amarillo, Wichita, Kansas City, St. Louis, Terre Haute, Indianapolis, Columbus, Pittsburgh, Philadelphia, and New York.

Although the Alpha served well, its real importance was its demonstration of Northrop's multicellular wing and stress skin construction. These concepts were of fundamental importance to the Douglas DC-2 and DC-3.

Transcontinental & Western Air (which was to become TWA) was the launch customer and ordered 5 alphas. Those aircraft began services on April 20, 1931 from San Francisco to New York with 13 intermediate stops. The entire trip took just over 23 hours.