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 a light bomber.

Northrop Gamma
Class Aircraft
Type Attack
Manufacturer Northrop Corporation
Origin United States of America
Country Name Origin Year
United States of America 1932
Country Name Operational Year Retirement Year
China View
Japan View
Spain View
United States of America 1932 View
ManufacturerName Production From Production To Quantity
Northrop Corporation 60 View

The Gamma was a further development of the successful Northrop Alpha 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.

The Gamma saw fairly limited civilian service as mail planes with Trans World Airlines 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 light attack aircraft. Military versions of the Gamma saw combat with Chinese and Spanish Republican air forces. Twenty Five Gamma 2Es were assembled in China from components provided by Northrop.

On June 2, 1933 Frank Hawks 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 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 during Lincoln Ellsworth's 1934 expedition to Antarctica. 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 finally flew over Antarctica.

On November 23, 1935, Ellsworth and Canadian pilot Herbert Hollick-Kenyon attempted the world's first trans-Antarctic flight from Dundee Island in the Weddell Sea 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 camp until being found by the Discovery II research vessel on January 15, 1936. "Polar Star" was later recovered and donated to the Smithsonian National Air and Space Museum where it resides to this day.

Role Civil/Attack
Manufacturer Northrop Corporation
Designer Jack Northrop
Introduction 1932
Number built 60
Developed from Northrop Alpha
Variants Northrop YA-13

General characteristics

  • Crew: one
  • Length: 31 ft 2 in (9.5 m)
  • Wingspan: 47 ft 9½ in (14.57 m)
  • Height: 9 ft 0 in (2.74 m)
  • Wing area: 363 ft² (33.7 m²)
  • Empty weight: 4,119 lb (1,868 kg)
  • Loaded weight: 7,350 lb (3,334 kg)
  • Powerplant: 1 × Wright R-1820 Cylone 9-cylinder Radial, 710 hp (530 kW)


  • Maximum speed: 223 mph (194 knots, 359 km/h) at 6,300 ft (1,920 m)
  • Cruise speed: 204 mph (177 knots, 328 km.h)
  • Range: 1,970 mi (1,713 NM, 3,170 km)
  • Service ceiling: 23,400 ft (7,130 m)
  • Rate of climb: 1,390 ft/min (7.1 m/s)
  • Wing loading: 20.2 lb/ft² (98.9 kg/m²)
  • Power/mass: 0.096 hp/lb (0.16 kW/kg)

End notes