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The Boeing 747-400 is a major development and the best-selling model of the Boeing 747 family of jet airliners. While retaining the four-engine wide-body layout of its predecessors, the 747-400 embodies numerous technological and structural changes to produce a more efficient airframe. Its most distinguishing features versus preceding 747 models are winglets mounted on wing tip extensions, which are found on all 747-400s except for Japanese domestic market versions. The 747-400 is equipped with a two-crew glass cockpit, which dispenses with the need for a flight engineer, along with more fuel-efficient engines, an optional fuel tank in the horizontal stabilizer, and revised fuselage/wing fairings. The aircraft also features an all-new interior with upgraded in-flight entertainment architecture. As on the 747-300, passenger variants include a stretched upper deck as standard. The model has a maximum capacity of 660 passengers with the 747-400D variant,〔(【引用サイトリンク】url=http://www.boeing.com/commercial/airports/misc/A20WE-Rev-45.pdf )〕 and can fly non-stop for up to with maximum payload, depending on model. Northwest Airlines first placed the 747-400 in commercial service in February 9, 1989. The 747-400 was produced in passenger (−400), freighter (−400F), combi (−400M), domestic (−400D), extended range passenger (−400ER) and extended range freighter (−400ERF) versions. The 747-400 is the second-most recent version of the Boeing 747 aircraft family, having been superseded by the more economical and advanced Boeing 747-8. Following its introduction in 1969, the Boeing 747 became a major success with airlines and the flying public. As the world's first wide-body jetliner, the 747 had revolutionized air travel, and cemented its manufacturer's dominance in the passenger aircraft market. In 1980, Boeing announced the 747-300, its latest 747 variant featuring greater passenger capacity. This was made possible by making a stretched upper deck (SUD), previously an option on the 747-200, a standard feature.〔(Boeing 747–300 ). Airliners.net〕 The SUD was almost twice as long as the original 747 upper deck. Besides increased capacity, the 747-300 did not offer any increase in range, nor did it include improvements in flight deck technology or construction materials. At the same time, 747s were becoming more costly to operate due to a number of factors, notably conventional flight control systems, three-person flight crews, and fuel costs.〔 In 1982, Boeing introduced a two-crew glass cockpit, new engines, and advanced materials on its 757 and 767 twinjets.〔 Similar technologies were also included in the design plans for newly announced rival wide-body aircraft, namely the Airbus A340 and McDonnell Douglas MD-11.〔 At the same time, combined sales of the 747-100, −200, and −300 models (collectively referred to as the 747 "Classics") neared 700, but new orders slowed precipitously. The introduction of the 747-300 did little to stem the decline, and itself faced potential competition from more modern designs. As a result, Boeing began considering a more significant upgrade for its largest passenger jet.〔 By early 1984, company officials had identified five development objectives for the latest 747 upgrade: new technologies, an enhanced interior, a range increase, more efficient engines, and a 10 percent reduction in operating cost.〔 In September 1984, Boeing announced development of the newest 747 derivative, the "Advanced Series 300", at the Farnborough Airshow.〔 On October 22, 1985, the type was officially launched when Northwest Airlines became the first 747-400 customer, with an order for 10 aircraft.〔 Cathay Pacific, KLM, Lufthansa, Singapore Airlines, and British Airways also announced orders several months later, followed by United Airlines, Air France, and Japan Airlines. ==Design effort== Seven early customers, mainly British Airways, Cathay Pacific, KLM, Lufthansa, Northwest, Qantas, and Singapore Airlines, formed a consultative group to advise Boeing on the 747-400's design process. While the aircraft was planned as a new-technology upgrade, Boeing originally proposed minimal design changes in order to reduce development cost and retain commonality with existing models.〔 The airline consultative group sought more advanced changes, including a two-crew glass cockpit. As a result of airline input, the 747-400's new digital cockpit design featured a hybrid of the cathode-ray tube (CRT) display technologies first employed on the 757 and 767, along with carry-over 747 systems such as its autopilot.〔 The 747-400's wingspan was stretched by over the Classic 747 through wingtip extensions. For reduced aerodynamic drag, the wings were fitted with -tall winglets. Despite the added length, the wings were lighter as a result of new aluminum alloys.〔 The horizontal tail was also redesigned to fit a fuel tank, resulting in a range increase, and the rudder travel was increased to 30 degrees.〔 The landing gear was redesigned with larger wheels and carbon brakes.〔 Internal changes further included a restyled cabin with new materials and updated fittings. New engines offered on the 747-400 included the Pratt & Whitney PW4056, the General Electric CF6-80C2B1F, and the Rolls-Royce RB211-524G/H.〔 The engines offered lower fuel consumption and greater thrust, along with a full-authority digital engine control (FADEC) which adjusted engine performance for improved efficiency compared with the Classic 747s.〔 A new auxiliary power unit (APU) manufactured by Pratt & Whitney Canada was also selected to provide on-ground power for the 747-400, with a 40 percent reduction in fuel consumption compared to previous APU designs.〔 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「Boeing 747-400」の詳細全文を読む スポンサード リンク
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