Stearman Cloudboy

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

History
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).

Variants

 * Model 6A Cloudboy
 * Initial civil production with a 165 hp Wright J-6 Whirlwind 5 engine, three built.


 * Model 6C Cloudboy
 * Re-engined with a 300 hp Wright J-6-9 Whirlwind (R-975-1), also designated YBT-3.


 * Model 6D Cloudboy
 * Re-engined with a 300 hp Pratt & Whitney Wasp Junior, also designated YBT-5


 * Model 6F Cloudboy
 * Re-engined with a 165 hp Continental A70 engine, also designated YBT-9A.


 * Model 6H Cloudboy
 * Re-engined with a 170 hp Kinner YR-720A engine, also designated YBT-9C.


 * Model 6L Cloudboy
 * Re-engined with a 200 hp Lycoming R-680-3 engine, also designated YBT-9B


 * Model 6P Cloudboy
 * One 6F re-engined with 1 220 hp Wright J-5 engine


 * YPT-9
 * Military production variant of the Model 6A with a 165 hp 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).


 * YPT-9A
 * One YPT-9 re-engined with a 165 hp Continental A70 (YR-545-1) engine, later converted to YPT-9B.


 * YPT-9B
 * One YPT-9 and one YPT-9A re-engined with a 200 hp Lycoming R-680-3 engine.


 * YPT-9C
 * YBT-3 re-engined with a 170 hp Kinner YR-720A engine.


 * YBT-3
 * One YPT-9 re-engined with a 300 hp Wright J-6-9 Whirlwind, later converted to a YPT-9C.


 * YBT-5
 * One YPT-9 re-engined with a 300 hp Pratt & Whitney R-985-1 Wasp Junior engine.


 * XPT-943
 * 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.


 * X-70
 * Alternative company designation for the XPT-943.

Operators

 * United States Army Air Corps
 * United States Army Air Corps

Surviving aircraft

 * 6002 – 6L airworthy at the Candler Field Museum in Williamson, Georgia.
 * 6003 – 6L airworthy at the Western Antique Aeroplane & Automobile Museum in Hood River, Oregon. It was previously owned by the Golden Wings Flying Museum.
 * 6004 – YPT-9B on display at the Yanks Air Museum in Chino, California. It was previously owned by the Boeing School of Aeronautics and was acquired by the museum in 1987.
 * 6010 – 6C airworthy with Robert Lock of Lakeland, Florida.