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The Convair 990 Coronado was a narrow-body four-jet airliner produced by the Convair division of General Dynamics, a "stretched" version of their earlier Convair 880 produced in response to a request from American Airlines. The 990 was lengthened by , which increased the number of passengers from between 88 and 110 in the 880, to between 96 and 121. This was still fewer than the contemporary Boeing 707 (110 to 189) or Douglas DC-8 (105 to 173), although the 990 was claimed to be faster than either in cruise. ==Design and development== American Airlines asked Convair to design an aircraft for coast-to-coast flights, able to fly nonstop from New York to Los Angeles against the wind. They wanted a somewhat larger passenger capacity than the 880, which was the smallest of the first-generation U.S. jet airliners. The 990 began flight testing January 24, 1961. One change from the 880 was the large anti-shock bodies on the upper trailing edge of the wings to increase the critical Mach and reduce transonic drag. Originally, there were no plans to use the outboard anti-shock bodies as fuel tanks. But to allow for increased range Convair modified the basic design to incorporate fuel storage in the outboard pods as well as those inboard. During test flights the extra weight caused outboard engine oscillations in certain conditions. So the outboard pylons were shortened 28 inches causing increased drag. The inner set of pods also served a secondary role as fuel dumps for the fuel tanks. The engines were also changed to the uprated General Electric CJ-805-23s, which were unique in that they used a fan stage at the rear of the engines, compared to the fan stage at the front of the engine found on the Pratt & Whitney JT3D that powered the 990's competitors. The engine was a simplified, non afterburning civil version of the J79, used in military fighters. Like the J79, the CJ805 was smoky. Like the 880, 990s incorporated a dorsal "raceway" added to the top of the fuselage to house the two ADF antennas and one VHF antenna 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「Convair 990 Coronado」の詳細全文を読む スポンサード リンク
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