The Northrop Gamma was a single-engine all-metal monoplane cargo

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

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 successful

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 Corpo ...

and shared its predecessor's aerodynamic innovations with wing fillets and multicellular stressed-skin wing construction. Like late Alphas, the fixed landing gear was covered in distinctive aerodynamic spats, and the aircraft introduced a fully enclosed cockpit.

Operational history

The Gamma saw fairly limited civilian service as mail planes with

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 ...

but had an illustrious career as a flying laboratory and record-breaking aircraft. The US military found the design sufficiently interesting to encourage Northrop to develop it into what eventually became the

Northrop A-17 The Northrop A-17, a development of the Northrop Gamma 2F model, was a two-seat, single-engine, monoplane, attack bomber built in 1935 by the Northrop Corporation for the United States Army Air Corps. When in British Commonwealth service during W ...

light attack aircraft. Military versions of the Gamma saw combat with

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of ...

and Spanish Republican air forces.Smith 1986 Twenty Five Gamma 2Es were assembled in

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

from components provided by Northrop; these were deployed in various attack missions during the early stages of the

Second Sino-Japanese War The Second Sino-Japanese War (1937–1945) or War of Resistance (Chinese term) was a military conflict that was primarily waged between the Republic of China and the Empire of Japan. The war made up the Chinese theater of the wider Pacific Th ...

, particular against Imperial Japanese naval assets.Eden and Moeng 2002, pp. 74–77. In the morning of 11 November 1937, three Chinese Air Force Northrop 2ECs of the 2nd BG, 14th Squadron led by Capt. Yu attacked the IJN

fleet aircraft carrier A fleet carrier is an aircraft carrier designed to operate with the main fleet of a nation's navy. The term was developed during World War II, to distinguish it from the escort carrier and other less capable types. In addition to many medium-siz ...

''Kaga'' off the Ma'anshan Islands; the bombs fell wide into Kaga's wake, and the Chinese Gammas were pursued and intercepted by three A5Ms of Kaga's

combat air patrol Combat air patrol (CAP) is a type of flying mission for fighter aircraft. A combat air patrol is an aircraft patrol provided over an objective area, over the force protected, over the critical area of a combat zone, or over an air defense area, ...

led by flight leader

Jirō Chōno Jirō Chōno was an officer and ace fighter pilot in the Imperial Japanese Navy (IJN) during the Second Sino-Japanese War. In combat over China, he was officially credited with destroying seven enemy aircraft. Chōno died in action on 21 Febr ...

, shooting down two (Gammas no. 1405 of Sung I-Ching and Li Xi-Yong, and no. 1402 of Peng Te-Ming and Li Huan-Chieh) while Yu managed to escape into the clouds and return his damaged Gamma to base. The Welding Gang

On June 2, 1933

Frank Hawks Frank Monroe Hawks (March 28, 1897 - August 23, 1938) was a pilot in the United States Army Air Service during World War I and was known during the 1920s and 1930s as a record breaking aviator, using a series of Texaco-sponsored aircraft, setting ...

flew his Gamma 2A "Sky Chief" from Los Angeles to New York in a record 13 hours, 26 minutes, and 15 seconds. In 1935,

Howard Hughes Howard Robard Hughes Jr. (December 24, 1905 – April 5, 1976) was an American business magnate, record-setting pilot, engineer, film producer, and philanthropist, known during his lifetime as one of the most influential and richest people in th ...

improved on this time in his modified Gamma 2G making the west-east transcontinental run in 9 hours, 26 minutes, and 10 seconds. The most famous Gamma was the ''Polar Star''. The aircraft was carried via ship and offloaded onto the pack ice in the

Ross Sea The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who vi ...

during

Lincoln Ellsworth Lincoln Ellsworth (May 12, 1880 – May 26, 1951) was a polar explorer from the United States and a major benefactor of the American Museum of Natural History. Biography Lincoln Ellsworth was born on May 12, 1880, to James Ellsworth and Eva F ...

's 1934 expedition to

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

. The Gamma was almost lost when the ice underneath it broke, and had to be returned to the United States for repairs. ''Polar Star''s second assignment to Antarctica in September 1934 was also futile — a connecting rod broke and the aircraft had to be returned yet again for repairs. On January 3, 1935, Ellsworth and pilot

Bernt Balchen Bernt Balchen (23 October 1899 – 17 October 1973) was a Norwegian pioneer polar aviator, navigator, aircraft mechanical engineer and military leader. A Norwegian native, he later became an American citizen and was a recipient of the Distingu ...

finally flew over Antarctica. On November 23, 1935, Ellsworth and Canadian pilot

Herbert Hollick-Kenyon Herbert Hollick-Kenyon (17 April 1897 – 30 July 1975) was a British aircraft pilot who made significant contributions towards aviation in Antarctica. Early life Herbert Hollick-Kenyon was born in London on 17 April 1897. His mother, Annie Ka ...

attempted the world's first trans-Antarctic flight from

Dundee Island Dundee Island is an ice-covered island lying east of the northeastern tip of Antarctic Peninsula and south of Joinville Island. It is named after the city of Dundee in Scotland. The Petrel Base is a scientific station in Antarctica belonging t ...

in the

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha ...

to Little America. The crew made four stops during their journey, in the process becoming the first people ever to visit Western Antarctica. During one stop, a blizzard completely packed the fuselage with snow which took a day to clear out. On December 5, after traveling over 2,400 miles (3,865 km) the aircraft ran out of fuel just 25 miles (40 km) short of the goal. The intrepid crew took six days to travel the remainder of the journey and stayed in the abandoned

Richard E. Byrd Richard Evelyn Byrd Jr. (October 25, 1888 – March 11, 1957) was an American naval officer and explorer. He was a recipient of the Medal of Honor, the highest honor for valor given by the United States, and was a pioneering American aviator, p ...

camp until being found by the

Discovery II ''Discovery II'', built in 1971, is the second of three Discovery sternwheel riverboats operated by the Riverboat Discovery company. ''Discovery II'' is still in use as a tour vessel on the Chena and Tanana rivers near Fairbanks, Alaska. Hist ...

research vessel on January 15, 1936. ''Polar Star'' was later recovered and donated to 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

;Gamma 2A: First production aircraft, sold to Texaco and flown by

as "Sky Chief", 785 hp (585 kW) Wright radial engine. ;Gamma 2B: Two-seat version with tandem controls, flown across Antarctica as the ''Polar Star'', 500 hp (373 kW) Pratt & Whitney Wasp radial engine. ; Gamma 2C (YA-13): Northrop-proposed attack version to compete with Curtiss A-12 Shrike armed with 4x 0.30 cal machine guns in the wings, 1x 0.30 cal machine gun on a flexible mount for rear defence, and up to 1,100 lb (500 kg) of bombs under the wings, evaluated by

USAAC 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 r ...

in 1933 ; XA-16: YA-13 prototype redesignated after being fitted with a Pratt & Whitney R-1830-9 engine ;Gamma 2D: Cargo version used by TWA, three built, 710 hp (529 kW) Wright Cyclone engine. One aircraft was converted into an "Experimental Overweather Laboratory" studying icing, superchargers, radios, and turbulence at 20,000–35,000 ft (6,100–10,670 m), then used by USAAC under the designation UC-100. Another retired TWA aircraft was used by Spanish Republican air force for coastal patrol. ;Gamma 2E: Similar to Gamma 2C in armament except for a 1,600 lb (727 kg) bomb load, used by the

Republic of China Air Force The Republic of China Air Force, retroactively known by its historical name the Chinese Air Force and unofficially referred to as the Taiwanese Air Force, is the military aviation branch of the Republic of China Armed Forces, currently based i ...

as a light bomber until

1938 Events January * January 1 ** The Constitution of Estonia#Third Constitution (de facto 1938–1940, de jure 1938–1992), new constitution of Estonia enters into force, which many consider to be the ending of the Era of Silence and the a ...

with a number of aircraft built in China, one, as ''K5053'', used by the British

Aeroplane & Armament Experimental Establishment The Aeroplane and Armament Experimental Establishment (A&AEE) was a research facility for British military aviation from 1918 to 1992. Established at Martlesham Heath, Suffolk, the unit moved in 1939 to Boscombe Down, Wiltshire, where its work ...

, and two supplied to the

Imperial Japanese Navy Air Service The was the Naval aviation, air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War. The Japanese military acquired their first air ...

, as the Northrop BXN, for evaluation in 1933. Cochran's Northrop Gamma 2G with Curtiss Conqueror V-12 engine

;Gamma 2F: Another attack version developed in parallel with Gamma 2C, entered service as

. ;Gamma 2G: Two-seat race version, originally with a

Curtiss Conqueror The Curtiss V-1570 Conqueror was a 12-cylinder vee liquid-cooled aircraft engine. Representing a more powerful version of the Curtiss D-12, the engine entered production in 1926 and flew in numerous aircraft.Gunston 1989, p. 46. Design and de ...

engine, later changed to Pratt & Whitney Twin Wasp Jr., then to

Wright Cyclone Wright Cyclone was the name given to a family of air-cooled radial piston engines designed by the Wright Aeronautical Corporation and used in numerous American aircraft in the 1930s and 1940s. Background The Wright Aeronautical Corporation was f ...

SGR-1820-G-5. Flown by

Jacqueline Cochran Jacqueline Cochran (May 11, 1906 – August 9, 1980) was an American pilot and business executive. She pioneered women's aviation as one of the most prominent racing pilots of her generation. She set numerous records and was the first woman to br ...

and

. ;Gamma 2H: Testbed for

Sperry Sperry may refer to: Places In the United States: *Sperry, Iowa, community in Des Moines County *Sperry, Missouri *Sperry, Oklahoma, town in Tulsa County *Sperry Chalet, historic backcountry chalet, Glacier National Park, Montana *Sperry Glacier, ...

automatic pilot, also flown by

Russell Thaw Russell William Thaw (October 25, 1910 – May 6, 1984) was an American airplane pilot. While working as the chief pilot for the Guggenheim family, he was sponsored for air races and excursions. He served during World War II in the United St ...

to a third-place finish in the 1935

Bendix Trophy The Bendix Trophy is a U.S. aeronautical racing trophy. The transcontinental, point-to-point race, sponsored by industrialist Vincent Bendix founder of Bendix Corporation, began in 1931 as part of the National Air Races. Initial prize money for ...

race. ;Gamma 2J: Two-seat trainer powered by 600 hp (448 kW) Pratt & Whitney Wasp with retractable undercarriage intended for USAAC.

North American BC-1 The North American Aviation T-6 Texan is an American single-engined advanced trainer aircraft used to train pilots of the United States Army Air Forces (USAAF), United States Navy, Royal Air Force, Royal Canadian Air Force and other air forces ...

preferred. Only one built.Francillon 1979, p.153. ;Gamma 2L: Used by Bristol for

Bristol Hercules The Bristol Hercules is a 14-cylinder two-row radial aircraft engine designed by Sir Roy Fedden and produced by the Bristol Engine Company starting in 1939. It was the most numerous of their single sleeve valve ( Burt-McCollum, or Argyll, typ ...

engine testing. ;Gamma 5A: One aircraft exported to

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

(designation BXN1) as a study in modern engineering. ;Gamma 5B: Two-seat version with the cockpits moved forward, used by the Spanish Republican air force for coastal patrol. ;Gamma 5D: One aircraft exported to Japan with "Army-type" equipment (designation BXN2), studied by Nakajima, then passed to Manchukuo National Airways which used it for aerial reconnaissance over China and USSR.

Operators

Military operators

; ; as BXN ; *

Spanish Republican Air Force The Spanish Republican Air Force was the air arm of the Armed Forces of the Second Spanish Republic, the legally established government of Spain between 1931 and 1939. Initially divided into two branches: Military Aeronautics ('' Aeronáutica M ...

– Northrop 2D and 5B Gamma ; *

United States 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 r ...

Civil operators

; * Manchukuo National Airways ; *

Specifications (Gamma 2D)

Gallery

File:NorthropGammaLeft.JPG, Left side of Gamma with landing gears File:NorthropGammaRightFront.JPG, Right front of Gamma File:NorthropGammaCockpit.JPG, Cockpit of Gamma File:NorthropGammaFront.JPG, Front end File:NorthropGammaSki.JPG, Wooden landing ski File:NorthropGammaPropeller.JPG, Propeller File:NorthropGammaleftfront.JPG, Front left of Gamma

References

;Notes ;Bibliography * Eden, Paul and Soph Moeng. ''The Complete Encyclopedia of World Aircraft''. London: Amber Books Ltd., 2002. . * Francillon, René J. ''McDonnell Douglas Aircraft since 1920''. London:Putnam, 1979. . * Smith, M.J. Jr. ''Passenger Airliners of the United States, 1926–1991''. Missoula, Montana: Pictorial Histories Publishing Company, 1986. .

External links

Northrop Gamma photographs/history

{{Japanese Navy short aircraft designations 1930s United States civil utility aircraft

Gamma Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter re ...

Low-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1932 1930s United States mailplanes Battles of the Second Sino-Japanese War