Douglas O-2
1924 observation aircraft family by Douglas
The Douglas O-2 was a 1920s American observation aircraft built by the Douglas Aircraft Company, powered by the Liberty engine of WW1 fame, with some later variants using other engines. It was developed into several versions, with 879 being produced in total. It was used in combat by the Chinese Air Force in the 1930s and also was the basis for a successful mailplane version.
Development
The important family of Douglas observation aircraft sprang from two XO-2 prototypes, the first of which was powered by the 420 hp (313 kW) Liberty V-1650-1 V-engine and test-flown in the autumn of 1924. The second XO-2 was powered by the 510 hp (380 kW) Packard 1A-1500 Vee engine, which proved unreliable. The US Army ordered 45 O-2 production aircraft in 1925, which retained the XO-2's welded steel tube fuselage, wooden wings, and overall fabric covering. It introduced aluminum panels on the forward fuselage. The XO-2 had been flown with short and long-span wings, the latter giving improved handling and therefore being specified for the production aircraft. The fixed tailskid landing gear included a main unit of the divided type, the horizontal tail surface was strut-braced, and the engine was cooled by a tunnel radiator.
The O-2 proved to be a conventional but very reliable biplane, which soon attracted orders for 25 more aircraft: 18 O-2A machines equipped for night flying and six O-2B dual-control command aircraft for the US Army, plus one civil O-2BS modified specially for James McKee, who made a remarkable trans-Canada flight in September 1926.
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