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The Douglas DC-3 is a fixed-wing propeller-driven airliner. Its cruise speed () and range () revolutionized air transport in the 1930s and 1940s. Its lasting effect on the airline industry and World War II makes it one of the most significant transport aircraft ever made. The DC-3 was a twin engine metal monoplane, developed as a larger, improved 14 bed sleeper version of the Douglas DC-2. It had many exceptional qualities compared to previous aircraft. It was fast, had a good range and could operate from short runways. It was also reliable, easy to maintain and carried passengers in greater comfort. Before the war it pioneered many air travel routes. It was able to cross the continental US, making transcontinental flights and worldwide flights possible, and is considered to be the first airliner that could make money by carrying passengers alone. 〔http://www.smithsonianmag.com/history/how-the-dc-3-revolutionized-air-travel-5444300/?no-ist〕 Civil DC-3 production ended in 1942 with only 607 aircraft being produced. However, together with its military derivative, the C-47 Skytrain (designated the Dakota in RAF Service), and with Russian and Japanese built versions, over 16,000 were built. Following the Second World War, the airliner market was flooded with surplus C-47s and other transport aircraft and attempts to produce an upgraded super DC-3 were a failure. While the DC-3 was soon made redundant on main routes by more advanced types such as the Douglas DC-6 and Lockheed Constellation, the design continued to prove exceptionally adaptable and useful. Large numbers continued to see service in a wide variety of niche roles well into the 21st century. Approximately 400 DC-3s and converted C-47s are still flying to this day as a testament to the durability of the design, many examples being over 70 years old. There is speculation that the DC-3 may become the first airliner to see over a century of operation.〔http://www.bbc.com/culture/story/20131009-dc3-still-flying-at-70〕 ==Design and development== The designation "DC" stands for "Douglas Commercial". The DC-3 was the culmination of a development effort that began after an inquiry from Transcontinental and Western Airlines (TWA) to Donald Douglas. TWA's rival in transcontinental air service, United Airlines, was starting service with the Boeing 247 and Boeing refused to sell any 247s to other airlines until United's order for 60 aircraft had been filled.〔O'Leary 1992, p. 7.〕 TWA asked Douglas to design and build an aircraft to allow TWA to compete with United. Douglas' design, the 1933 DC-1, was promising, and led to the DC-2 in 1934. The DC-2 was a success, but there was room for improvement. The DC-3 resulted from a marathon telephone call from American Airlines CEO C. R. Smith to Donald Douglas, when Smith persuaded a reluctant Douglas to design a sleeper aircraft based on the DC-2 to replace American's Curtiss Condor II biplanes. (The DC-2's cabin was wide, too narrow for side-by-side berths.) Douglas agreed to go ahead with development only after Smith informed him of American's intention to purchase twenty aircraft. The new aircraft was engineered by a team led by chief engineer Arthur E. Raymond over the next two years, and the prototype DST (for Douglas Sleeper Transport) first flew on December 17, 1935 (the 32nd anniversary of the Wright Brothers' flight at Kitty Hawk). Its cabin was wide, and a version with 21 seats instead of the 14-16 sleeping berths〔Berths were long; lowers were wide and uppers were .〕 of the DST was given the designation DC-3. There was no prototype DC-3; the first DC-3 built followed seven DSTs off the production line and was delivered to American Airlines.〔Pearcy 1987, p. 17.〕 The DC-3 and DST popularized air travel in the United States. Eastbound transcontinental flights could cross the U.S. in about 15 hours with three refueling stops; westbound trips against the wind took 17 hours. A few years earlier such a trip entailed short hops in slower and shorter-range aircraft during the day, coupled with train travel overnight.〔O'Leary 2006, p. 54.〕 A variety of radial engines were available for the DC-3. Early-production civilian aircraft used Wright R-1820 Cyclone 9s, but later aircraft (and most military versions) used the Pratt & Whitney R-1830 Twin Wasp which gave better high-altitude and single engine performance. Three DC-3S ''Super DC-3s'' with Pratt & Whitney R-2000 Twin Wasps were built in the late 1940s. 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 DC-3」の詳細全文を読む スポンサード リンク
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