The Stearman XOSS was an American biplane observation floatplane developed by

Stearman Aircraft Stearman Aircraft Corporation was an aircraft manufacturer in Wichita, Kansas. Although the company designed a range of other aircraft, it is most known for producing the Model 75, which is commonly known simply as the "Stearman" or "Boeing ...

for the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

during the late 1930s. Intended to replace the

Curtiss SOC Seagull The Curtiss SOC Seagull was an American single-engined scout observation seaplane, designed by Alexander Solla of the Curtiss-Wright Corporation for the United States Navy. The aircraft served on battleships and cruisers in a seaplane configurati ...

in service aboard battleships, it proved inferior to the

Vought OS2U Kingfisher The Vought OS2U Kingfisher is an American catapult-launched observation floatplane. It was a compact mid-wing monoplane, with a large central float and small stabilizing floats. Performance was modest because of its low-powered engine. The OS2U ...

in a fly-off, and did not enter production.

Design and development

Known by the company designation Model X-85,Phillips 2006, p.148. the Stearman XOSS-1 was designed during 1937 in response to a U.S. Navy specification calling for an observation-scout type aircraft, capable of operating from either water or land, and stressed for catapult launching from battleships and cruisers.Adcock 1991, p.4. The new aircraft was intended to replace the Curtiss SOC as the standard observation and gunnery spotting aircraft in service aboard the Navy's battleships. In response to the request for proposals, the Navy received designs from

, Chance Vought, and the

Naval Aircraft Factory The Naval Aircraft Factory (NAF) was established by the United States Navy in 1918 in Philadelphia, Pennsylvania. It was created to help solve aircraft supply issues which faced the Navy Department upon the entry of the U.S. into World War I. ...

. The Stearman Model 85, given the designation XOSS-1, was a conventional two-seat biplane, with the pilot and observer seated in tandem in a fully enclosed cockpit. The aircraft could be operated with either float or wheeled landing gear, with the former being of the single center-float type, and the latter being a conventional

taildragger Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...

undercarriage. The XOSS-1 had the unusual feature of being fitted with full-span flaps on the upper wing to reduce stalling speed. It was powered by a

Pratt & Whitney R-1340 The Pratt & Whitney R-1340 Wasp is an aircraft engine of the reciprocating type that was widely used in American aircraft from the 1920s onward. It was the Pratt & Whitney aircraft company's first engine, and the first of the famed Wasp series ...

Wasp radial engine.

Operational history

Flying for the first time in September 1938, the XOSS-1 proved to have benign flying characteristics, and over the next several months was evaluated against the Naval Aircraft Factory XOSN, another conventional biplane, and the Vought XOS2U, a mid-wing monoplane. The evaluation proved that the XOSS-1 was conventional in all respects; the full-span upper-wing flap reduced the aircraft's landing speed to , while the top speed achievable was . Both the XOSS-1 and the XOSN-1, despite not possessing any significant faults, were considered to be insufficiently advanced, being inferior in performance and potential to the Vought machine. The XOS2U-1 was declared the winner of the competition in May 1939, and the XOSS-1's development came to an end. The aircraft was used for liaison purposes by the Navy, being scrapped at

NAS Jacksonville Naval Air Station Jacksonville (NAS Jacksonville) is a large naval air station located approximately eight miles (13 km) south of the central business district of Jacksonville, Florida, United States., effective 2007-10-25 Location NAS Jack ...

in 1941.Baugher 2010

Operators

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Specifications (XOSS-1)

References

Citations

Bibliography

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External links

Stearman XOSS-1 at Aviation Enthusiast Corner.
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