|
The Douglas A-1 Skyraider (formerly AD) was an American single-seat attack aircraft that saw service between the late 1940s and early 1980s. The Skyraider had a remarkably long and successful career; it became a piston-powered, propeller-driven anachronism in the jet age, and was nicknamed "Spad", after the French World War I fighter.〔Burgess and Rausa 2009, p. 7.〕 It was operated by the United States Navy (USN), the United States Marine Corps (USMC) and the United States Air Force (USAF), and also saw service with the British Royal Navy, the French Air Force, the Air Force of the Republic of Vietnam (VNAF), and others. In U.S. service, it was finally replaced by the LTV A-7 Corsair II swept wing subsonic jet in the early 1970s. ==Design and development== The piston-engined Skyraider was designed during World War II to meet United States Navy requirements for a carrier-based, single-seat, long-range, high performance dive/torpedo bomber, to follow-on from earlier types such as the Helldiver and Avenger.〔Parker, Dana T. ''Building Victory: Aircraft Manufacturing in the Los Angeles Area in World War II,'' p. 33, Cypress, CA, 2013. ISBN 978-0-9897906- 0-4.〕 Designed by Ed Heinemann of the Douglas Aircraft Company, prototypes were ordered on 6 July 1944 as the XBT2D-1. The XBT2D-1 made its first flight on 18 March 1945 and in April 1945, the USN began evaluation of the aircraft at the Naval Air Test Center (NATC).〔Swanborough and Bowers 1976, p. 176.〕 In December 1946, after a designation change to AD-1, delivery of the first production aircraft to a fleet squadron was made to VA-19A.〔Swanborough and Bowers 1976, p. 177.〕 The AD-1 was built at Douglas' El Segundo plant in Southern California. In his memoir ''The Lonely Sky'', test pilot Bill Bridgeman quotes a production rate of two aircraft per day, describing the routine yet sometimes hazardous work of certifying AD-1s fresh off the assembly line for delivery to the U.S. Navy in 1949 and 1950.〔Bridgeman and Hazard 1955, pp. 38–40.〕 The low-wing monoplane design started with a Wright R-3350 radial engine, later upgraded several times. Its distinctive feature was large straight wings with seven hard points apiece. These gave the aircraft excellent low-speed maneuverability, and enabled it to carry a large amount of ordnance over a considerable combat radius and loiter time for its size, comparable to much heavier subsonic or supersonic jets. The aircraft was optimized for the ground-attack mission and was armored against ground fire in key locations unlike faster fighters adapted to carry bombs, such as the Vought F4U Corsair or North American P-51 Mustang, which would be retired by U.S. forces before the 1960s. Shortly after Heinemann began design of the XBT2D-1, a study was issued that showed for every of weight reduction the takeoff run was decreased by , the combat radius increased by and the rate-of-climb increased by . Heinemann immediately had his design engineers begin a program for finding weight-saving on the XBT2D-1 design, no matter how small. Simplifying the fuel system resulted in a reduction of ; by eliminating an internal bomb bay and hanging the bombs, drop tanks and rockets from the wings or fuselage; by using a fuselage dive brake; and by using an older tailwheel design. In the end, Heinemann and his design engineers found over of weight savings on the original XBT2D-1 design.〔("Headaches of a Jet Designer." ) ''Popular Mechanics'', January 1953, pp. 81-85, 248.〕 The Navy AD series was initially painted in ANA 623 Glossy Sea Blue, but during the 1950s following the Korean War, the color scheme was changed to light gull grey (FS26440) and white (FS27875). Initially using the gray and white Navy pattern, by 1967 the USAF began to paint its Skyraiders in a camouflaged pattern using two shades of green, and one of tan. Used by the USN over Korea and Vietnam, the A-1 was a primary close air support aircraft for the USAF and VNAF during the Vietnam War. The A-1 was famous for being able to take hits and keep flying. There was added armor plating around the cockpit area for added pilot protection. It was replaced beginning in the mid-1960s by the Grumman A-6 Intruder as the Navy's primary medium-attack plane in supercarrier-based air wings; however Skyraiders continued to operate from the smaller Essex class carriers. The Skyraider went through seven versions, starting with the AD-1, then AD-2 and AD-3 with various minor improvements, then the AD-4 with a more powerful R-3350-26WA engine. The AD-5 was significantly widened, allowing two crew to sit side-by-side (this was not the first multiple-crew variant, the AD-1Q being a two-seater and the AD-3N a three-seater); it also came in a four-seat night-attack version, the AD-5N. The AD-6 was an improved AD-4B with improved low-level bombing equipment, and the final production version AD-7 was upgraded to a R-3350-26WB engine. For service in Vietnam, USAF Skyraiders were fitted with the Stanley Yankee extraction system,〔http://www.ejectionsite.com/yankee.htm〕 which acted similarly to an ejection seat, though with a twin rocket pulling the escaping pilot from the cockpit. In addition to serving during Korea and Vietnam as an attack aircraft, the Skyraider was modified into a carrier-based airborne early warning aircraft, replacing the Grumman TBM-3W Avenger. It served in this function in the USN and Royal Navy, being replaced by the Grumman E-1 Tracer and Fairey Gannet respectively in those services.〔 Skyraider production ended in 1957 with a total of 3,180 built. In 1962, the existing Skyraiders were redesignated A-1D through A-1J and later used by both the USAF and the Navy in the Vietnam War. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Douglas A-1 Skyraider」の詳細全文を読む スポンサード リンク
|