The 990 did not meet the specifications promised, and American Airlines reduced its order as a result. The 990A was developed by adding fairings to the engine nacelles, among other changes. Despite the modifications from the basic 880 and those in response to drag problems in testing, the aircraft never lived up to its promise of coast-to-coast nonstop capability from JFK to LAX. American Airlines' timetables show little or no difference in scheduled time between 707 and 990A flights. AA began to dispose of its 990As in 1967. During May 1961, one of the pre-production 990 aircraft, while demonstrating the margin between its operating speed and its capability during a dive at .97 Mach from 32,000 ft to 22,500 ft, reached at an altitude of : the fastest true airspeed ever attained by a commercial jet transport at that time. However, in level flight the maximum speed, 0.84 M, was less than that guaranteed to American Airlines, 0.89 M, because the drag levels with the anti-shock bodies were much higher than predicted. A drag reduction program was instituted during which streamlining of the engine pylon/wing interface and addition of nacelle fairings achieved 0.89 M. In 1963, the 990A was reported to burn per hour of fuel at at at a mass of . In contrast, a modern
Boeing 737 MAX 8 typically carries 162 passengers and burns per hour at at sub-optimal parameters. 990A Coronado "St Gallen" at
Manchester Airport in 1964
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 Their fleet was withdrawn from service in 1975.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 (SAS) also operated 990A Coronados on their long-haul schedules to Tokyo and other destinations in the Far East and also to South America and Africa. ,
GE J79 turbojet-derived
GE CJ805 engines The 990's niche was soon captured by the
Boeing 720 and
Boeing 720B, derivatives of the
Boeing 707, and later by the
Boeing 727. By the time the assembly line shut down in 1963, only 37 990s had been produced, bringing General Dynamics' entire production of commercial jet airliners to 102 airframes. The failure of airlines to broadly accept the Convair 880 and 990 led Convair's parent company, General Dynamics, to suffer one of the largest corporate losses in history. As a result, Convair exited the jet airliner business, although it later built fuselages for
McDonnell Douglas, specifically for the
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, as 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. ==Variants==