Douglas O-2

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O-2
Type Observation plane
Manufacturer Douglas Aircraft Company
Primary user United States Army Air Corps
Produced 1924
Variants Douglas O-38
Douglas XA-2
Douglas M-1

The Douglas O-2 is a 1920s American observation aircraft built by the Douglas Aircraft Company.

Contents

[edit] 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 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.[1]

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.[1]

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.[2]

[edit] Variants

O-2 - Initial production model - 45 built.[1]

O-2A - O-2 with night flying equipment - 18 built.[1]

O-2B - Dual control version of O-2 - six built.[1]

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.[1]

O-2D: Unarmed staff transport versions of the 0-2C - two built.[1]

O-2E: A one-off aircraft which replaced the wire link between upper and lower wing ailerons of production aircraft by rigid struts.[1]

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.[1]

O-2J: Unarmed dual control version of the 0-2H for service as USAAC staff transports - three built.[1]

O-2K/BT-1: A slightly modified version of the O2J for US Army staff transport and liaison duties. Total production was 37 for the USAAC and 20 for the National Guard - 59 built.[1]

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].[1]

XO-6B: Radically altered (smaller and lighter) version of the XO-6 - one built.[1]

O-7: Three 0-2s with the 510-hp (380 kW) Packard 2A-1500 direct-drive engine. Two were later converted to 0-2 standards, and one to the O-2C standard.[1]

O-8: One aircraft with the 400-hp (298 kW) Curtiss R-1454 radial engine instead of the intended Packard inverted-Vee engine. It later became an 0-2A.[1]

O-9: One aircraft with the 500-hp (373 kW) Packard 3A-1500 geared engine. It resembled the 0-7 but had a four rather than two bladed propeller. It later became an O-2A.[1]

XO-14: One reduced-scale version of an 0-2H, with a 220 hp (164 kW) Wright J-5 engine,[2] and the first Douglas aircraft with wheel brakes.[1]

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.[1]

OD-1: Two O-2Cs for service with the US Marine Corps from 1929.[1]

O-22: Three identical to O-2H except for the installation of a swept-back upper wing and a Pratt & Whitney Wasp engine.[2]

O-25: One late-type O-2H airframe with a Curtiss Conqueror engine, and a revised nose.[2]

O-25A: Forty-nine production versions of the O-25.[2]

Y1O-29: Later designated O-29A: was an O-2K fitted with a Wright R-1750 Cyclone engine.[2]

O-32/BT-2: Pratt & Whitney R-1340-3 Wasp engine, most later fitted with anti-drag rings.[2] BT-2s were designated A-4 for use as radio-controlled target drones.

  • One O-32/BT-2
  • 30 O-32A/BT-2A
  • 146 BT-2B
  • 20 BT-2C

O-34: The last O-22 with a Curtiss Conqueror engine.[2]

O-38: See Douglas O-38

[edit] Specifications (0-2)

Data from The Complete Encyclopedia of World Aircraft [3]

General characteristics

  • 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:V-1650 Liberty V-12 piston engine, 420 hp (313 kW)

Performance

Armament

  • 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

[edit] References

  1. ^ a b c d e f g h i j k l m n o p q r s "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.
  2. ^ a b c d e f g h "United States Military Aircraft Since 1909" by F. G. Swanborough & Peter M. Bowers (Putnam New York, ISBN 085177816X) 1964, 596 pp.
  3. ^ The Complete Encyclopedia of World Aircraft Editors: Paul Eden & Soph Moeng, 2002, ISBN 0-7607-3432-1, page 614.

[edit] See also