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The Jet Age is a period in the history of aviation defined by the advent of aircraft powered by turbine engines, and by the social change this brought about. Jet airliners were able to fly much higher, faster, and further than older pistonpowered propliners, making transcontinental and intercontinental travel considerably faster and easier: for example, aircraft leaving North America and crossing the Atlantic Ocean (and later, the Pacific Ocean) could now fly to their destinations non-stop, making much of the world accessible within a single day's travel for the first time. Since large jetliners could also carry more passengers than piston-powered airliners, air fares also declined (relative to inflation), so people from a greater range of social classes could afford to travel outside of their own countries. The one exception to jet-powered domination by large airliners was the contra-rotating turboprop design that powered the Tu-114 (first flight 1957). This airliner was able to match or even exceed the speed, capacity and range of contemporary jets; however, the use of such powerplants in large airframes was totally restricted to the military after 1976. The introduction of the Concorde supersonic transport (SST) airliner to regular service in 1976 was expected to bring similar social changes, but the aircraft never found commercial success. After several years of service, a fatal crash near Paris in July 2000 and other factors eventually caused Concorde flights to be discontinued in 2003. This was the only loss of an SST in civilian service. Only one other SST design was used in a civilian capacity, the Soviet era Tu-144, but it was soon withdrawn due to high maintenance and other issues. McDonnell Douglas, Lockheed and Boeing were three U.S. manufacturers that had originally planned to develop various SST designs since the 1960s, but these projects were eventually abandoned for various developmental, cost, and other practical reasons. ==Origins== The term "Jet Age" was coined in the late 1940s. At the time, the only jet-powered aircraft in production were military types, most of which were fighters. The expression reflects the recognition that the jet engine had effected, or would soon, a profound change in aeronautics and aviation. In one view, the jet age began with the invention of the jet engine in the 1930s and 1940s.〔("The jet age," ''Encyclopaedia Britannica'' )〕 In the history of military aviation it began in 1944 with the introduction into service of the Arado Ar 234 reconnaissance bomber and the Messerschmitt Me 262 fighter during World War II.〔("Military Aircraft," ''Encyclopaedia Britannica'' )〕〔Green, W.; "Warplanes of the Third Reich", Macdonald and Jane's (1970).〕 In commercial aviation the jet age was introduced to Britain in 1952 with the first scheduled flight of the de Havilland Comet airliner and to America some years later with the first American-built jet airliners.〔("Sixty years of the jet age," ''Flight Global'' )〕〔"The Jet Age, 1958 - today," ''America by air'', Smithsonian national Air and Space Museum.()〕 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「jet age」の詳細全文を読む スポンサード リンク
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