Convair 990 Coronado
The Convair 990 Coronado was an American narrow-body four-engined jet airliner,a stretched version of their earlier Convair 880 produced in response to a request from American Airlines.They wanted a larger passenger capacity than the 880,which was the smallest of the first-generation U.S. jet airliners and 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.The inboard shock bodies,which were larger,were also used for additional fuel tankage.
The 990 was lengthened by 10 ft (3.0 m),which increased the number of passengers from between 88 and 110 in the 880 to between 96 and 121 in the 990,still fewer passengers than the contemporary Boeing 707 (110 to 189) or Douglas DC-8 (105 to 173),although the 990 was 25–35 mph faster than either in cruise.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,like most versions of the J79,the CJ805 and CJ805-23 were smoky, although secondary operator Spantax eventually had their 990 aircraft refitted with smokeless combustion chambers in the 1970s.
The 990 did not meet the specifications promised,and American Airlines reduced their order as a result.The 990A was developed by adding fairings to the engine nacelles, among other changes.Despite the modifications the aircraft never lived up to its promise of coast-to-coast nonstop capability from JFK to LAX.AA began to dispose of their 990As in 1967.
The Convair 990A is still the fastest non-supersonic commercial transport to have ever been produced.During May 1961, one of the pre-production 990 prototype aircraft set a record of .97 Mach in level flight at an altitude of 22,500 ft.,equivalent to a true airspeed of 675 mph.This was before the various aerodynamic drag-reduction changes were applied to the later 990A,as such,it would have been capable of speeds slightly in excess of 700 mph.
Swissair bought eight 990As beginning in 1962,operating them on long-distance routes to South America, West Africa, the Middle and Far East, as well as on European routes with heavy traffic. Their fleet was withdrawn from service in 1975. Scandinavian Airlines also operated Coronados on their long-haul schedules to Tokyo and other destinations in the Far East.
The failure of airlines to broadly accept the Convair 880 and 990 led Convair's parent company,General Dynamics,to suffer what at the time was one of the largest corporate losses in history.Convair exited the jet airliner business,although they later profitably built fuselages for the McDonnell Douglas DC-10, KC-10 and MD-11.
When the major airlines retired their Convair 990s,they found a second life on charter airlines.Spantax of Spain had a large fleet until the mid-1980s and so did Denver Ports of Call.In 1967,Alaska Airlines purchased Convair 990 PP-VJE from Varig,and operated it as N987AS in scheduled airline service until 1975.
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