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发表于 2007-10-28 21:58:15
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来自： 中国陕西西安
The 747SP, or "Special Performance," was first delivered in 1976. The SP was developed to target two market requirements. The first was to offer a smaller model to compete with the McDonnell Douglas DC-10 and Lockheed L-1011, while maintaining commonality with the larger standard 747s. The 747 was simply too big for many routes, and Boeing did not have a mid-sized widebody to compete in the segment of the market that the DC-10 and L-1011 had created. The second market requirement was the ultra long-range routes which were emerging in the mid-1970s. This required not only a longer range, but a higher cruising speed. Boeing could not afford to develop an all-new design, so instead shortened the 747 and re-optimized it for speed and range at the expense of capacity.
Apart from having a shorter fuselage, the 747SP differs from other 747 variants in having a larger tail surface and simpler wing flap system. The 747SP uses larger single-piece flaps on the trailing edges (other 747s use triple flaps). The SP could typically only accommodate 220 passengers in a 3-class cabin, but could fly over at speeds of up to . Some airline insiders call it the "74 Short" or "Baby Jumbo" because of its shortened fuselage, and stubby appearance. Originally it was designated 747SB (for "Short Body", later was nicknamed "Sutter's Balloon" by Boeing employees, after 747 chief engineer Joe Sutter). Boeing later changed the production designation to 747SP, reflecting the aircraft's longer range and faster cruise speed. Pan Am was the launch customer for the 747SP, taking the first delivery, Clipper Freedom, on March 5 1976.Norris, p. 74
The 747SP was the longest-range airliner available until the 747-400 entered service in 1989. For all its technical achievements, the SP never sold as well as Boeing hoped. Only 45 were ever built and most that are still in service are used by operators in the Middle East. One special 747SP is the SOFIA astronomical observatory, where the airframe was modified to carry a 2.5-meter-diameter infrared reflecting telescope to high-altitude, the limit to which infrared penetrates the atmosphere. Originally delivered to Pan Am and titled "Clipper Lindbergh", NASA has displayed the name in Pan Am script on the plane.
Past 747SP operators include:
* Pan Am took delivery of ten 747-SP21 aircraft between 1975 and 1979, operating them on trans-Pacific routes to Asia and Oceania. The aircraft and routes were sold to United Airlines in 1986, and remained in operation until 1994.
* South African Airways operated six 747-SP44 aircraft on flights from Johannesburg to London, during the apartheid years, when that airline's aircraft were not allowed to fly over African countries and had to fly around the Bulge of Africa. The extra range allowed aircraft to cover the additional distance.
* TWA operated three 747-SP31 aircraft from 1979 to 1986. Two of these were purchased by American Airlines and used on London and Tokyo routes until 1993.
* Iran Air took delivery of four 747-SP86 aircraft between 1976 and 1978. Prior to the 1979 Islamic revolution, the aircraft were used on the daily Tehran-New York flight, at the time the longest non-stop airline route in the world.
* Qantas operated two 747-SP38 aircraft from 1980 to 2004.
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整理总结的很直观全面的21空调系统
33章灯光 简介
新型与经典型飞机刹车系统简述
发表于 2007-10-28 21:09:34
[s:93] [s:93]
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