Douglas Dolphin

Dolphin
US Coast Guard RD2 in June, 1932
Role	Flying boat
Manufacturer	Douglas Aircraft Company
Introduction	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.^[1]

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

A U.S. Coast Guard RD-1.

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.^[2]

Military operators

The sole surviving Douglas Dolphin at the National Museum of Naval Aviation.

 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: 2 × 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)

See also

Aircraft of comparable role, configuration and era

• General Aviation PJ
• Saro Cloud
• Saro Cutty Sark
• Grumman Goose
  

Related lists

• List of military aircraft of the United States
• List of military aircraft of the United States (naval)
  

References

Notes

1. ^ "Douglas 1930s." U.S. Centennial of Flight Commission, 2003. Retrieved: November 26, 2010.
2. ^ "Mayflower of the Air Ready for President." Popular Mechanics, May 1933.

Bibliography

• Bowers, Peter M. "Douglas Dolphin." Airpower, Volume 12, Number 6, November 1982, pp. 11–25, 49-50.
• Francillon, René J. McDonnell Douglas Aircraft since 1920. London: Putnam, 1979. ISBN 0-370-00050-1.