Douglas A2D Skyshark

A2D Skyshark
A production A2D-1 in flight
Role Attack aircraft
National origin United States
Manufacturer Douglas Aircraft Company
First flight 26 March 1950
Status Canceled
Primary user United States Navy
Number built 12 (4 never flew)
Developed from A-1 Skyraider

The Douglas A2D Skyshark is an American turboprop-powered attack aircraft built by the Douglas Aircraft Company for the United States Navy.

Design and development

Douglas A2D-1 Skyshark BuNo. 125485 (seventh of 10 prototype a/c) at Idaho Falls Regional Airport

On 25 June 1945, the Bureau of Aeronautics (BuAer) asked Douglas Aircraft for a turbine-powered, propeller-driven aircraft.[1] Three proposals were put forth in the next year and a half: the D-557A, to use two General Electric TG-100s (T31s) in wing nacelles; the D-557B, the same engine, with counter-rotating propellers; and the D-557C, to use the Westinghouse 25D.[1] These were canceled, due to engine development difficulties, but BuAer continued to seek an answer to thirsty jets.[1]

On 11 June 1947,[1] Douglas got the Navy's letter of intent for a carrier-based turboprop. The need to operate from Casablanca-class escort carriers dictated the use of a turboprop instead of jet power.[2]

The sole surviving XA2D Skyshark on display, 2014

While it resembled the AD Skyraider, the A2D was different in a number of unseen ways. The Allison XT-40-A2 at 5,100 hp (3,800 kW)[3] had more than double the horsepower of the Skyraider's R-3350.[3] The XT40 installation on the Skyshark used contra-rotating propellers to harness all the available power. Wing root thickness decreased, from 17% to 12%, while both the height of the tail and its area grew.[3]

Engine development problems delayed the first flight until 26 May 1950, made at Edwards Air Force Base by George Jansen.[3]

Navy test pilot Cdr. Hugh Wood was killed attempting to land the first prototype XA2D-1, BuNo 122988, on 19 December 1950, on its 15th flight. He was unable to check the rate of descent, resulting in a high-impact crash on the runway.[4] Investigation found the starboard power section of the coupled Allison XT40A turboprop engine had failed and did not declutch, allowing the Skyshark to fly on the power of the opposite section, nor did the propellers feather. As the wings' lift disappeared, a fatal sink rate was induced. Additional instrumentation and an automatic decoupler was added to the second prototype, but by the time it was ready to fly on 3 April 1952, sixteen months had passed, and with all-jet designs being developed, the A2D program was essentially dead. Total flight time on the lost airframe was barely 20 hours.[5]

Allison failed to deliver a "production" engine until 1953, and while testing an XA2D with that engine, test pilot C. G. "Doc" Livingston pulled out of a dive and was surprised by a loud noise and pitch up. His windscreen was covered with oil and the chase pilot told Livingston that the propellers were gone. The gearbox had failed, but Livingston successfully landed the airplane.[6] By the summer of 1954, the A4D was ready to fly. The escort carriers were being mothballed, and time had run out for the troubled A2D program.[7]

Due largely to the failure of the T40 program to produce a reliable engine, the Skyshark never entered operational service.

Twelve Skysharks were built, two prototypes and ten preproduction aircraft. Most were scrapped or destroyed in accidents, and only one has survived.[8]

Aircraft on display

  • A2D-1 Skyshark, BuNo. 125485, is at the airport in El Cajon, California, San Diego Air And Space Museum Hangar as of 30 March 2016. It was restored for static display by Pacific Fighters ca. 1995.[9]

Specifications (XA2D-1)

Drawings for the A2D-1

Data from Encyclopedia of American Aircraft[10]

General characteristics

Performance

Armament

See also

Related development

Aircraft of comparable role, configuration and era

Related lists

Notes

  1. 1 2 3 4 Francillon 1979, p. 472.
  2. ↑ Heinemann and Rausa 1980, p. 177.
  3. 1 2 3 4 Francillon 1979, p. 473.
  4. ↑ Heinemann and Rausa 1980, p. 180.
  5. ↑ McCullough, Anson. "Skyshark", Wings (Sentry Publications, Granada Hills, California, October 1995, Volume 25, Number 5), pp. 18–20.
  6. ↑ "An Aeroproducts Installation Engineer Remembers". Aeroproducts Propellers. Retrieved 6 February 2018.
  7. ↑ Heinemann and Rausa 1980, p. 183.
  8. ↑ "Douglas A2D Skyshark Survivor". Goleta Air & Space Museum. Retrieved 21 January 2016.
  9. ↑ "A2D Skyshark/125485". Airliners.net. Retrieved: 13 December 2012.
  10. ↑ Baugher, Joe (2001-10-24). "Douglas XA2D-1 Skyshark". Encyclopedia of American Aircraft. Retrieved 2010-06-04.

Bibliography

  • Francillon, René J. McDonnell Douglas Aircraft since 1920. London: Putnam, 1979. ISBN 0-370-00050-1.
  • Heinemann, Edward, H. and Rausa, Rosario. Combat Aircraft Designer. London: Jane's Publishing, 1980. ISBN 0-7106-0040-2.
  • Markgraf, Gerry. Douglas Skyshark, A2D Turbo-Prop Attack (Naval Fighters No. 43). Simi Valley, CA: Ginter Books, 1997. ISBN 0-942612-43-4.
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