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Stearman XA-21

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XA-21
Stearman XA-21 with streamlined cockpit
General information
TypeGround attack
National originUnited States
ManufacturerStearman Aircraft
StatusPrototype
Primary userUnited States Army Air Corps
Number built1
History
First flight1938

The Stearman XA-21 (Model X-100) was a competitor in a United States Army Air Corps competition for a twin-engined attack aircraft which (after redesigns) led to the Douglas A-20 Havoc, Martin A-22 Maryland and North American B-25 Mitchell.

Design and development

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The X-100, designated XA-21 following purchase by the Army Air Corps, was a twin-engined high-winged monoplane of all-metal construction.[1] Its initial design featured an unusual "stepless cockpit" arrangement, much like those on most German World War II bombers designed during the war years from the He 111P onwards, with a streamlined, well-framed greenhouse canopy enclosing both the pilot and bombardier stations.[2]

Operational history

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The XA-21 was first tested with the streamlined cockpit but this configuration was found to restrict the pilot's forward vision, and the aircraft was rebuilt with a conventional (stepped) nose and cockpit structure.[3] Although this change in the cockpit did not significantly affect performance, the XA-21 was not ordered into production.'[4] The sole XA-21 had serial number 40-191.[5]

Operators

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 United States

Specifications (XA-21)

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In flight
Front view

Data from Museum of the United States Air Force[4]

General characteristics

  • Crew: 3
  • Capacity: 5,560 lb (2,520 kg)
  • Length: 53 ft 1 in (16.18 m)
  • Wingspan: 65 ft 0 in (19.81 m)
  • Height: 14 ft 2 in (4.32 m)
  • Wing area: 607 sq ft (56.39 m2)
  • Empty weight: 12,760 lb (5,789 kg)
  • Gross weight: 18,230 lb (8,269 kg)
  • Powerplant: 2 × Pratt & Whitney R-2180-7 Twin Hornet radial engines, 1,400 hp (1,030 kW) each

Performance

  • Maximum speed: 223 kn (257 mph, 414 km/h)
  • Cruise speed: 174 kn (200 mph, 322 km/h)
  • Wing loading: 30.0 lb/sq ft (147 kg/m2)
  • Power/mass: 0.15 hp/b (250 W/kg)

Armament

  • Guns: ** 4 × wing-mounted 0.30 in (7.6 mm) M1919 Browning machine guns
    • 1 × nose-mounted 0.30 in (7.6 mm) in machine gun
    • 4 × aft-firing 0.30 in (7.6 mm) in machine guns
  • Bombs: 2,700 lb (1,200 kg)

See also

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Related lists

References

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Notes

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  1. ^ "Stearman XA-21 (Stepped Cockpit)." Museum of the United States Air Force. Retrieved: 17 July 2017.
  2. ^ Bowers 1989, p. 273.
  3. ^ "Swift Attack Bombers Race For Jobs In Army Air Corps." Popular Mechanics, June 1939.
  4. ^ a b "Stearman XA-21 (Streamlined Cockpit)." Museum of the United States Air Force. Retrieved: 17 July 2017.
  5. ^ Phillips, Edward (2006). Stearman Aircraft: A Detailed History. North Branch, MN: specialtypress. pp. 135–138, 202. ISBN 9781580070874.

Bibliography

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  • Bowers, Peter M. Boeing Aircraft since 1916. London: Putnam, Second edition, 1989. ISBN 0-85177-804-6.
  • Wagner, Ray. American Combat Planes of the 20th Century, Third Enlarged Edition. New York: Doubleday, 1982. ISBN 978-0-930083-17-5.
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