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. 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; these were deployed in various attack missions during the early stages of the Second Sino-Japanese War, particular against Imperial Japanese naval assets. 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 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 led by flight leader Jirō Chōno, 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. 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. For details of the 14 variants, click here. Specifications below are for the Gamma 2D variant. Gamma 2A Gamma 2E Gamma 2G Gamm 2J Northrop A-17 derivative
