Douglas Dolphin

Dolphin

Picture - US Coast Guard RD2 in June, 1932

Role: Flying boat
Manufacturer: Douglas Aircraft Company
Introduced: 1931
Primary users: United States Navy United States Coast Guard
Number built: 58

The Douglas Dolphin was an amphibious flying boat. While only 58 were built, they served a wide variety of roles: private "yacht," airliner, military transport, and search and rescue.

Design and development

The Dolphin originated in 1930 as the "Sinbad," a pure flying boat without wheels. The Sinbad was intended as a luxurious flying yacht. The Great Depression had curtailed demand for such extravagance, but Douglas managed to interest the United States Coast Guard who not only bought the Sinbad, but 12 Dolphins.

Undaunted by the lack of demand, Douglas improved the Sinbad in 1931 so that it was amphibious, and could land on water or land. The improved aircraft was named "Dolphin", however this did not represent the end of development, as many detail improvements were made, including an increase in the length of over a foot and several changes were made to the empennage, engine nacelles and wings.

Operational history

The first two were purchased by Wilmington-Catalina Airlines to fly passengers between Los Angeles and Santa Catalina Island, becoming the first successful Douglas airliners. Subsequent examples were ordered by the United States Navy and US Coast Guard for use as transports and search and rescue craft. The US Army Air Corps ordered several under the designations C-21, C-26, and C-29. Many were eventually ordered for their original purpose as luxury transports. Owners included William Boeing, the founder of the Boeing Company, and Philip K. Wrigley, the son of the founder of the Wm. Wrigley Jr. Company. William K. Vanderbilt bought two with custom interiors for use from the Vanderbilt yacht Alva as flying tenders.

One was procured by the US Navy as a transport for President Franklin D. Roosevelt. Although never used by Roosevelt, this was the first aircraft procured to provide transportation for the President of the United States.

Military operators

Argentina

Argentina

Australia

Royal Australian Air Force

United States

US Army Air Corps
US Army Air Force
United States Coast Guard
US Marine Corps
United States Navy

Specifications (Dolphin)

General characteristics

Crew: Two, pilot and co-pilot
Capacity: Six passengers
Length: 45 ft 1 in (13.74 m)
Wingspan: 60 ft 0 in (18.29 m)
Height: 14 ft 0 in (4.27 m)
Wing area: 592 ft² (55.0 m²)
Empty weight: 7,000 lb (3,175 kg)
Max takeoff weight: 9,530 lb (4,323 kg)
Powerplant: 2x— Pratt & Whitney R-985 radial engines, 450 hp (336 kW) each

Performance

Maximum speed: 156 mph (217 km/h)
Range: 720 mi (1,159 km)
Service ceiling: 17,000 ft (5,180 m)
Rate of climb: 710 ft/min (216 m/min)

Comparable aircraft

General Aviation PJ-1
Saro Cloud
Saro Cutty Sark
Grumman Goose

Bibliography

Francillon, René J. McDonnell Douglas Aircraft since 1920. London: Putnam, 1979. ISBN 0-370-00050-1.

Douglas Dolphin Pictures

More aircraft.

Source: WikiPedia