The Northrop Alpha was an American single-engine, all-metal, seven-seat, low-wing

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

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 Northrop Grumman Corporation is an American Multinational corporation, multinational Aerospace manufacturer, aerospace and Arms industry, defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one ...

based in

Burbank, California Burbank is a city in the southeastern end of the San Fernando Valley in Los Angeles County, California, United States. Located northwest of downtown Los Angeles, Burbank has a population of 107,337. The city was named after David Burbank, w ...

Design and development

Drawing on his experience with the

Lockheed Vega The Lockheed Vega is an American five- to seven-seat high-wing monoplane airliner built by the Lockheed Corporation starting in 1927. It became famous for its use by a number of record-breaking pilots who were attracted to the rugged and very l ...

, 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 The Guggenheim Aeronautical Laboratory at the California Institute of Technology (GALCIT), was a research institute created in 1926, at first specializing in aeronautics research. In 1930, Hungarian scientist Theodore von Kármán accepted the dire ...

at the

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

, and a multicellular stressed-skin wing of Northrop's own design which was later successfully used on the

Douglas DC-2 The Douglas DC-2 is a 14-passenger, twin-engined airliner that was produced by the American company Douglas Aircraft Company starting in 1934. It competed with the Boeing 247. In 1935, Douglas produced a larger version called the DC-3, which b ...

and

Douglas DC-3 The Douglas DC-3 is a propeller-driven airliner manufactured by Douglas Aircraft Company, which had a lasting effect on the airline industry in the 1930s to 1940s and World War II. It was developed as a larger, improved 14-bed sleeper version ...

. 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.Smith 1986 The Alpha was further developed into a dedicated fast transport, the

Northrop Gamma The Northrop Gamma was a single-engine all-metal monoplane cargo aircraft used in the 1930s. Towards the end of its service life, it was developed into the A-17 light bomber. Design and development The Gamma was a further development of the su ...

Operational history

The Alpha entered service with Transcontinental & Western Air (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 Amarillo ( ; Spanish for "yellow") is a city in the U.S. state of Texas and the seat of Potter County. It is the 14th-most populous city in Texas and the largest city in the Texas Panhandle. A portion of the city extends into Randall County ...

; 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.Smith 1986 TWA's were initially operated as a passenger service but the Alpha's were later modified at the Stearman factory in Wichita into the cargo-carrying 4A model with a new type certificate. Stearman and Northrop had the same parent company at the time. The third Alpha built, NC11Y, was reacquired by TWA in 1975, and is preserved at the Smithsonian

National Air and Space Museum The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States. Established in 1946 as the National Air Museum, it opened its main building on the Nat ...

Variants

;Alpha 2: six-passenger version ;Alpha 3: two-passenger plus cargo version, several Alpha 2s were converted to this configuration ;Alpha 4: cargo version with 2 ft (0.6 m) increased wingspan and large metal fairings encapsulating the main gear for drag reduction. All were converted from Alpha 3s ;Alpha 4A: cargo version, all converted from Alpha 4s ; YC-19 & Y1C-19: military VIP transport, seating reduced to four passengers, serial numbers 31-516 to 31-518, YC-19 had a Pratt & Whitney R-1340-7, while the Y1C-19s had the R-1340-11 engineFahey 1946, p. 24.

Operators

; *

Trans World Airlines Trans World Airlines (TWA) was a major American airline which operated from 1930 until 2001. It was formed as Transcontinental & Western Air to operate a route from New York City to Los Angeles via St. Louis, Kansas City, and other stops, with F ...

US Army Air Corps The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical ri ...

Specifications (Alpha 2)

References

;Notes ;Bibliography * Eden, Paul and Soph Moeng. ''The Complete Encyclopedia of World Aircraft''. London: Amber Books Ltd., 2002. . * Fahey, James C. ''U.S. Army Aircraft 1908-1946 (Heavier-Than-Air) ''. New York: Ships and Aircraft, 1946. * Smith, M.J. Jr. ''Passenger Airliners of the United States, 1926-1991''. Missoula, Montana: Pictorial Histories Publishing Company, 1986. . * Swanborough, F. Gordon and Peter M. Bowers. ''United States Military Aircraft Since 1909''. New York: Putnam, 1964. .

External links

"Low-Wing Metal Monoplane Develops High Speed," ''Popular Mechanics Monthly'', July 1930, p. 7 bottom
{{Wright Field project numbers 1930s United States airliners

Alpha Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...

Low-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1930 1930s United States mailplanes