Stearman Cloudboy

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Model 6 Cloudboy
Stearman YBT-3.jpg
The YBT-3
Role Training biplane
Manufacturer Stearman Aircraft Company
First flight 1931
Primary user United States Army Air Corps
Produced 1930-1931
Number built 7

The Stearman Model 6 Cloudboy was a 1930s American training biplane designed and built by the Stearman Aircraft Company of Wichita, Kansas.


The Cloudboy was designed as a commercial or military trainer. Due to economic pressure during the Great Depression, only a few aircraft were built. Three civil models were built, followed by four similar aircraft for evaluation by the United States Army Air Corps. Designated YPT-9 by the Army, it failed to gain any orders. All models went through a number of engine changes (resulting in new designations for both the military and civil aircraft).

Today, the Cloudboy is an extremely rare aircraft; only four Model 6 Cloudboys are still registered. Known examples include: N787H, serial number 6002, owned by Ronald Alexander and displayed at the Candler Field Museum in Williamson, Georgia;[1] N788H, serial number 6003, on display at the Golden Wings Flying Museum in Blaine, Minnesota;[2] N795H, serial number 6004, on display at the Yanks Air Museum in Chino, California; N786H, serial number 6010.


Model 6L Stearman Cloudboy (YBT-9B), N787H
Model 6A Cloudboy
Initial civil production with a 165hp (123kW) Wright J-6 Whirlwind 5 engine, three built.
Model 6C Cloudboy
Re-engined with a 300hp (224kW) Wright J-6-9 Whirlwind (R-975-1), also designated YBT-3.
Model 6D Cloudboy
Re-engined with a 300hp (224kW) Pratt & Whitney Wasp Junior, also designated YBT-5
Model 6F Cloudboy
Re-engined with a 165hp (123kW) Continental A70 engine., also designated YBT-9A.
Model 6H Cloudboy
Re-engined with a 170hp (127kW) Kinner YR-720A engine, also designated YBT-9C.
Model 6L Cloudboy
Re-engined with a 200hp (149kW) Lycoming R-680-3 engine, also designated YBT-9B
Model 6P Cloudboy
One 6F re-engined with 1 220hp Wright J-5 engine
Military production variant of the Model 6A with a 165hp (123kW) Wright J-6 Whirlwind 5 engine, four built (one converted to YPT-9A, one to YPT-9B, one to YBT-3 and one YBT-5).
One YPT-9 re-engined with a 165hp (123kW) Continental A7] (YR-545-1) engine, later converted to YPT-9B.
One YPT-9 and one YPT-9A re-engined with a 200hp (149kW) Lycoming R-680-3 engine.
YBT-3 re-engined with a 170hp (127kW) Kinner YR-720A engine.
One YBT-9 re-engined with a 300hp (224kW) Wright J-6-9 Whirlwind, later converted to a YPT-9C.
One YBT-9 re-engined with a 300hp (224kW) Pratt & Whitney Wasp Junior engine.
A primary trainer derived from the 6A for evaluation at Wright Field. Formed the origins of the Stearman NS and PT-13 for the US Navy and USAAC respectively.
Alternative company designation for the XPT-943.


 United States
United States Army Air Corps

Specifications (YPT-9B)[edit]

Data from United States Military Aircraft since 1909[3]

General characteristics

  • Crew: 2
  • Length: 24 ft 8 in (7.52 m)
  • Wingspan: 32 ft 0 in (9.76 m)
  • Height: 9 ft 7 in (2.92 m)
  • Wing area: 272 ft2 (25.3 m2)
  • Gross weight: 2,814 lb (1,279 kg)
  • Powerplant: 1 × Lycoming R-680-3, 200 hp (149 kW) each


  • Maximum speed: 135 mph (217 km/h)
  • Range: 490 miles (789 km)
  • Service ceiling: 17,000 ft (5,183 m)
  • Rate of climb: 1,050 ft/min (5.3 m/s)

See also[edit]

Related lists


  • Andrade, John (1979). U.S.Military Aircraft Designations and Serials since 1909. Midland Counties Publications. ISBN 0-904597-22-9. 
  • Swanborough, F.G; Bowers, Peter M. (1963). United States Military Aircraft since 1909. London: Putnam. 
  • Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions. 
  • The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing. p. 2958. 

External links[edit]