|Manufacturer||Douglas Aircraft Company|
|Primary user||United States Army Air Corps|
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 0-2 production aircraft in 1925, these retaining the XO-2's welded steel tube fuselage, wooden wings and overall fabric covering but at the same time introducing aluminium 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 0-2 proved to be a conventional but very reliable biplane which soon attracted orders for 25 more aircraft: 18 0-2A machines equipped for night flying and six 0-2B dual-control command aircraft for the US Army, plus one civil 0-2BS modified specially for James McKee, who made a remarkable solo transCanada flight in September 1926. In 1927 the O-2BS was adapted as a threeseater with a radial engine.
The O-2Hs were an entirely new design but continued the same basic model number. Major differences were heavily staggered wings, a more compact engine installation, and clean landing gear secured to the fuselage.
O-2 - Initial production model - 45 built.
O-2A - O-2 with night flying equipment - 18 built.
O-2B - Dual control version of O-2 - six built.
O-2C: These differed from the 0-2 in having frontal radiators for their Liberty engines and modified oleo-strut landing gear. The USAAC took delivery of 19 aircraft, while the remaining 27 went to reserve National Guard units - 32 built and one conversion from O-9.
O-2D: Unarmed staff transport versions of the 0-2C - two built.
O-2H: The fuselage was redesigned and a new tailplane was fitted, with staggered wings of unequal span. The O-2H incorporated the rigid-strut aileron interconnections of the 0-2E. An improved split-axle landing gear was standard. The USAAC received 90 O-2Hs between 1928 and 1930, and the National Guard a further 50 - 141 built.
O-2J: Unarmed dual control version of the 0-2H for service as USAAC staff transports - three built.
O-2M series: various export versions of O-2 that saw services with Republic of China Air Force. These aircraft were used as scout-bombers by the Chinese in the Second Sino-Japanese War with somewhat limited success against Japanese ground targets. It was also used by the Mexican Air Force with Lewis and Vickers machine guns, with very good results.
XO-6: Five all-metal O-2s, built in the mid-1920s by [Thomas-Morse].
XO-6B: Radically altered (smaller and lighter) version of the XO-6 - one built.
XA-2: The 46th aircraft of the original 0-2 contract was completed as an attack machine with the powerplant of one 420-hp (313 kW) V-1410 Liberty inverted-Vee engine, and with a total of eight machine-guns (two in the engine cowling, two each in the upper and lower wings, and two on a ring-mounting operated by the observer). It was remarkably well armed for its day, and competed against the Curtiss A-3 in 1926 but was not selected for production.
O-25A: Forty-nine production versions of the O-25.
- One O-32/BT-2
- 30 O-32A/BT-2A
- 146 BT-2B
- 20 BT-2C
Data from The Complete Encyclopedia of World Aircraft 
- Crew: two
- Length: 28 ft 9 in (8.76 m)
- Wingspan: 39 ft 8 in (12.09 m)
- Height: 10 ft 6 in (3.2 m)
- Wing area: 411 sq ft (38.18 m^2)
- Empty weight: 3,032 lb (1,375 kg)
- Max takeoff weight: 4,785 lb (2,170 kg)
- Powerplant: 1× V-1650 Liberty V-12 piston engine, 420 hp (313 kW)
- Maximum speed: 128 mph (206 km/h)
- Cruise speed: 103 mph (166 km/h)
- Range: 360 miles (579 km)
- Service ceiling: 16,279 ft (4,960 m)
- Rate of climb: 807 ft/min (246 m/min)
- Two .30-cal (7.62 mm) Browning machine guns, one fixed forward-firing and one flexible
- 400 lb (181 kg) of disposable stores carried under the lower wing
- "The Complete Encyclopedia of World Aircraft" cover Editors: Paul Eden & Soph Moeng, (Amber Books Ltd. Bradley's Close, 74-77 White Lion Street, London, NI 9PF, 2002, ISBN 0-7607-3432-1), 1152 pp.
- "United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.
- The Complete Encyclopedia of World Aircraft Editors: Paul Eden & Soph Moeng, 2002, ISBN 0-7607-3432-1, page 614.
|This article is licensed under the GNU Free Documentation License.|
It uses material from the Wikipedia article "Douglas O-2".