The Douglas XP3D was a prototype American patrol flying boat of the 1930s. A twin-engined 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 con ...

, the P3D was produced by the Douglas Aircraft Company to equip the

US 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 ...

's Patrol squadrons, but despite meeting the Navy's requirements, the rival

Consolidated PBY The Consolidated PBY Catalina is a flying boat and amphibious aircraft that was produced in the 1930s and 1940s. In Canadian service it was known as the Canso. It was one of the most widely used seaplanes of World War II. Catalinas served wit ...

was preferred owing to a lower price.

Development and design

In 1933, 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 ...

placed orders with both Douglas and

Consolidated Aircraft The Consolidated Aircraft Corporation was founded in 1923 by Reuben H. Fleet in Buffalo, New York, the result of the Gallaudet Aircraft Company's liquidation and Fleet's purchase of designs from the Dayton-Wright Company as the subsidiary was ...

for single prototypes of patrol flying boats, to replace the

Consolidated P2Y The Consolidated P2Y was an American flying boat maritime patrol aircraft. The plane was a parasol monoplane with a fabric-covered wing and aluminum hull. Development Initially created to compete for a U.S. Navy contract dated February 28, 19 ...

and Martin P3M that equipped the Navy's patrol squadrons.Swanborough and Bowers 1976, p.80. Douglas's design, the P3D, was designed in parallel with the smaller YB-11 being developed 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 ...

(which was eventually built as the YOA-5), and like the YB-11, was a twin-engined high-winged

with its engines (the new Pratt & Whitney R-1830 Twin Wasp

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 ...

mounted in nacelles above and ahead of the wing. Unlike the YB-11, it was a pure flying boat rather than an amphibian, and was therefore fitted with retractable beaching gear to allow it to be moved to and from shore, rather than a full undercarriage allowing operation from land or sea.Francillon 1979, p.194. The Douglas prototype, designated XP3D-1, first flew on 6 February 1935, and was delivered to

NAS San Diego Naval Air Station North Island or NAS North Island , at the north end of the Coronado peninsula on San Diego Bay in San Diego, California, is part of the largest aerospace-industrial complex in the United States Navy – Naval Base Coronado (NB ...

for testing in March 1935. Both the XP3D-1 and Consolidated's P3Y successfully passed the Navy's performance tests,Creed 1986, pp.32–33. demonstrated very similar performance, an order was placed for 60 P3Ys (re-designated PBY in May 1936) because the Consolidated aircraft was cheaper, costing $90,000 per aircraft compared with $110,000 for the Douglas aircraft.Francillon 1979, pp.194–195. Douglas re-designed the P3D to improve performance in order to win follow-on contracts, and rebuilt the XP3D-1, raising the wing by 27 inches (0.69 m) and mounting the engines on the leading edge of the wing. The fixed wing floats were replaced by retractable floats, and a nose turret was fitted. The rebuilt aircraft, designated XP3D-2 was re-delivered on 15 May 1935, but production orders again went to Consolidated, for the improved PBY-2.Francillon 1979, p.195.

Operational history

The XP3D-1 was briefly operated by Patrol Squadron 3 (

VP-3 VP-3 was a Patrol Squadron of the U.S. Navy. The squadron was established as Patrol Squadron 16-F (VP-16F) on 2 January 1937, redesignated Patrol Squadron 16 (VP-16) on 1 October 1937, redesignated Patrol Squadron 41 (VP-41) on 1 July 1939, redes ...

) until it was returned to Douglas for re-building. The re-built XP3D-2 was used by VP-11F as an VIP aircraft until destroyed in a crash at

Acapulco Bay Acapulco de Juárez (), commonly called Acapulco ( , also , nah, Acapolco), is a city and major seaport in the state of Guerrero on the Pacific Coast of Mexico, south of Mexico City. Acapulco is located on a deep, semicircular bay and has bee ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

on 8 February 1937. The crash was survived by the embarked VIP, Rear Admiral

Ernest King Ernest Joseph King (23 November 1878 – 25 June 1956) was an American naval officer who served as Commander in Chief, United States Fleet (COMINCH) and Chief of Naval Operations (CNO) during World War II. As COMINCH-CNO, he directed the U ...

Variants

;XP3D-1 :Prototype aircraft. Two 825 hp (615 kW) R-1830-58 engines. ;XP3D-2 :Rebuilt XP3D-1, with raised wing, engines moved to wing leading edge and retractable wing floats. Two 900 hp (671 kW) R-1830-64 engines.

Operators

; *

Specifications (XP3D-2)

References

;Notes ;Bibliography *Creed, Roscoe. ''PBY: The Catalina Flying Boat''. Shrewsbury, UK:Airlife Publishing, 1986. . *Francillon, René J. ''McDonnell Douglas Aircraft since 1920''. London:Putnam, 1979. . *Swanborough, Gordon and Peter M. Bowers. ''United States Navy Aircraft since 1911''. London:Putnam, 1976. . *Wagner, Ray, ''American Combat Planes'', Doubleday & Company, Garden City, New York, 1982,

External links

1000Aircraftphotos

''Time'', March 25, 1935. {{USN patrol aircraft Flying boats 1930s United States patrol aircraft High-wing aircraft P3D Aircraft first flown in 1935 Twin piston-engined tractor aircraft