The Douglas YOA-5 was an

Amphibious aircraft An amphibious aircraft or amphibian is an aircraft (typically fixed-wing) that can take off and land on both solid ground and water, though amphibious helicopters do exist as well. Fixed-wing amphibious aircraft are seaplanes ( flying boats ...

designed for the

United States Army Air Corps The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical r ...

. Although a prototype was built, it did not enter production.

Design and development

In November 1932, the U.S. Army ordered the development of an

amphibious Amphibious means able to use either land or water. In particular it may refer to: Animals * Amphibian, a vertebrate animal of the class Amphibia (many of which live on land and breed in water) * Amphibious caterpillar * Amphibious fish, a fish ...

reconnaissance aircraft/bomber, intended to act as navigation leaders and rescue aircraft for formations of conventional bombers. The resultant aircraft, which was ordered under the bomber designation YB-11, was designed in parallel with the similar but larger

Douglas XP3D The Douglas XP3D was a prototype American patrol flying boat of the 1930s. A twin-engined high-winged monoplane, the P3D was produced by the Douglas Aircraft Company to equip the US Navy's Patrol squadrons, but despite meeting the Navy's req ...

patrol

flying boat A flying boat is a type of fixed-winged seaplane with a hull, allowing it to land on water. It differs from a floatplane in that a flying boat's fuselage is purpose-designed for floatation and contains a hull, while floatplanes rely on fusela ...

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 ...

. It was a high-winged

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

with two

Wright R-1820 Cyclone The Wright R-1820 Cyclone 9 is an American radial engine developed by Curtiss-Wright, widely used on aircraft in the 1930s through 1950s. It was produced under license in France as the Hispano-Suiza 9V or Hispano-Wright 9V, and in the Soviet Uni ...

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ca ...

s mounted in individual nacelles above the wing, resembling an enlarged version of the

Douglas Dolphin The Douglas Dolphin is an American amphibious flying boat. While only 58 were built, they served a wide variety of roles including private air yacht, airliner, military transport, and search and rescue. Design and development The Dolphin origin ...

. Prior to completion, it was redesignated firstly as an observation aircraft YO-44 and then as the YOA-5 'observation amphibian model 5'.Wagner, Ray, ''American Combat Planes'', 1981, Doubleday & Company, Garden City, New York, , page 307 It first flew during January 1935, and was delivered to the army during February that year.Francillon 1979, p.192. The concept for which it was designed proved impracticable, and no further production ensued, but the YOA-5 was used to set two world distance records for amphibians, being finally scrapped in December 1943.Francillon 1979, pp. 192–193.

Operators

; *

Variants

;YB-11 :An amphibious reconnaissance bomber ordered in 1932 by the US Army Air Corps, powered by 2x

Wright R-1820-13 Cyclone The Wright R-1820 Cyclone 9 is an American radial engine developed by Curtiss-Wright, widely used on aircraft in the 1930s through 1950s. It was produced under license in France as the Hispano-Suiza 9V or Hispano-Wright 9V, and in the Soviet Uni ...

radial engines. ;YO-44 :The YB-11 redesignated in the Observation category before completion. ;YOA-5 :Another redesignation to the Observation Amphibian category. One built, given the aforementioned designations at various times in its life. The YOA-5 started life with

engines, was re-engined with

Wright YR-1820-45 Cyclone The Wright R-1820 Cyclone 9 is an American radial engine developed by Curtiss-Wright, widely used on aircraft in the 1930s through 1950s. It was produced under license in France as the Hispano-Suiza 9V or Hispano-Wright 9V, and in the Soviet Uni ...

engines for experimental long-range flying, then re-engined again with

Wright R-1820-25 Cyclone The Wright R-1820 Cyclone 9 is an American radial engine developed by Curtiss-Wright, widely used on aircraft in the 1930s through 1950s. It was produced under license in France as the Hispano-Suiza 9V or Hispano-Wright 9V, and in the Soviet Uni ...

Specifications (YOA-5)

References

Bibliography

*Francillon, René. ''McDonnell Douglas Aircraft since 1920''. London:Putnam, 1979. .

External links

USAF Museum description of YB-11
{{USAF amphibious aircraft OA-5 Douglas B-11 High-wing aircraft Amphibious aircraft Aircraft first flown in 1935 Twin piston-engined tractor aircraft