Northrop Alpha

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Northrop Alpha.jpg
Northrop Alpha - NASA Photo
DesignerJohn K. Northrop
First flight1930
IntroductionApril 20, 1931
Retired1975 to Smithsonian Institution
Primary users Transcontinental & Western Air
US Army Air Corps
Number built17 [1]
Variants Northrop Gamma
C-19 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. [1]

Monoplane Fixed-wing aircraft with a single main wing plane

A monoplane is a fixed-wing aircraft with a single main wing plane, in contrast to a biplane or other multiplane, each of which has multiple planes.

Northrop Corporation 1939–1984 aerospace manufacturer in the United States

Northrop Corporation was a leading United States aircraft manufacturer from its formation in 1939 until its 1994 merger with Grumman to form Northrop Grumman. The company is known for its development of the flying wing design, most successfully the B-2 Spirit stealth bomber.

Burbank, California City in California, United States

Burbank is a city in Los Angeles County in the Los Angeles metropolitan area of Southern California, United States, 12 miles (19 km) northwest of downtown Los Angeles. The population at the 2010 census was 103,340.


Design and development

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 the 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. [2]

Lockheed Vega Utility transport aircraft by Lockheed

The Lockheed Vega is an American six-passenger 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 long-range design. Amelia Earhart became the first woman to fly solo across the Atlantic Ocean in one, and Wiley Post used his to prove the existence of the jet stream after having flown around the world twice.

Fillet (mechanics) rounded edge or corner of a manufactured object

In mechanical engineering, a fillet is a rounding of an interior or exterior corner of a part design. An interior or exterior corner, with an angle or type of bevel, is called a "chamfer". Fillet geometry, when on an interior corner is a line of concave function, whereas a fillet on an exterior corner is a line of convex function. Fillets commonly appear on welded, soldered, or brazed joints.

Guggenheim Aeronautical Laboratory Building at the California Institute of Technology

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 directorship of the lab and emigrated to the United States. Under his leadership, work on rockets began there in 1936. GALCIT was the first—and from 1936 to 1940 the only—university-based rocket research center. Based on GALCIT's JATO project at the time, the Jet Propulsion Laboratory was established under a contract with the United States Army in November 1943.

The Alpha was further developed into a dedicated fast transport, the Northrop Gamma.

Northrop Gamma Multi-role aircraft family by Northrop

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.

Operational history

Alpha in TWA colors on display at the National Air and Space Museum NorthropAlphaTWA.JPG
Alpha in TWA colors on display at the National Air and Space Museum
Under the Northrop Alpha NorthropAlphaBottom.JPG
Under the Northrop Alpha

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; 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. [2]

Trans World Airlines 1930-2001 airline in the United States

Trans World Airlines (TWA) was a major American airline that existed 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 Ford Trimotors. With American, United, and Eastern, it was one of the "Big Four" domestic airlines in the United States formed by the Spoils Conference of 1930.

Rick Husband Amarillo International Airport airport

Rick Husband Amarillo International Airport is a public airport six miles (10 km) east of downtown Amarillo, in Potter and Randall Counties, Texas, United States. The airport was renamed in 2003 after NASA astronaut and Amarillo native Rick Husband, who died in the Space Shuttle Columbia disaster in February of that year.

Northrop C-19 Alpha

The Northrop C-19 Alpha was a series of three aircraft purchased from Northrop by the US Army Air Corps in 1931. They were slightly modified versions of the civil Northrop Alpha Type 2.

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. [1]

National Air and Space Museum Aviation museum in Washington, D.C.

The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C. It was established in 1946 as the National Air Museum and opened its main building on the National Mall near L'Enfant Plaza in 1976. In 2018, the museum saw approximately 6.2 million visitors, making it the fifth most visited museum in the world, and the second most visited museum in the United States. The museum contains the Apollo 11 command module, the Friendship 7 capsule which was flown by John Glenn, Charles Lindbergh's Spirit of St. Louis, the Bell X-1 which broke the sound barrier, the model of the starship Enterprise used in the science fiction television show Star Trek: The Original Series, and the Wright brothers' airplane near the entrance.


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, [3] YC-19 had a Pratt & Whitney R-1340-7, while the Y1C-19s had the R-1340-11 engine [4]


Flag of the United States.svg  United States
USAAC Northrop Alpha Northrop Alpha (Y1C-19).jpg
USAAC Northrop Alpha

Specifications (Alpha 2)

General characteristics

Wingspan distance from the tip of one limb such as an arm or wing to the tip of the paired limb, or analogically the same measure for airplane wings

The wingspan of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777-200 has a wingspan of 60.93 metres, and a wandering albatross caught in 1965 had a wingspan of 3.63 metres, the official record for a living bird. The term wingspan, more technically extent, is also used for other winged animals such as pterosaurs, bats, insects, etc., and other fixed-wing aircraft such as ornithopters. In humans, the term wingspan also refers to the arm span, which is distance between the length from one end of an individual's arms to the other when raised parallel to the ground at shoulder height at a 90º angle. Former professional basketball player Manute Bol stands at 7 ft 7 in (2.31 m) and owns one of the largest wingspans at 8 ft 6 in (2.59 m).

In aviation, manufacturer's empty weight (MEW) is the weight of the aircraft "as built" and includes the weight of the structure, power plant, furnishings, installations, systems and other equipment that are considered an integral part of an aircraft before additional operator items are added for operation.

Maximum takeoff weight Maximum weight of a craft at which takeoff is permitted

The maximum takeoff weight (MTOW) or maximum gross takeoff weight (MGTOW) or maximum takeoff mass (MTOM) of an aircraft is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. The analogous term for rockets is gross lift-off mass, or GLOW. MTOW is usually specified in units of kilograms or pounds.


See also

Related development

Aircraft of comparable role, configuration and era

Related Research Articles

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  1. 1 2 3 Eden and Moeng 2002, pp. 74–77.
  2. 1 2 Smith 1986
  3. Swanborough and Bowers 1964, p. 596.
  4. Fahey 1946, p. 24.