Convair 990 Coronado

Convair 990 Coronado
Convair CV-990A of Spantax at Basle Airport. Even at landing power the smoky engines are evident.
Role	Narrow-body jet airliner
Manufacturer	Convair
Primary user	American Airlines
Produced	1961-1963
Number built	37
Developed from	Convair 880

The Convair 990 Coronado was a narrow-body 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 10 feet, which increased the number of passengers from between 88 and 110 in the 880, to between 96 and 121 (depending on the interior). This was still considerably fewer than the contemporary Boeing 707 (110 to 189) or Douglas DC-8 (105 to 173), although the 990 remained some 25 to 35 mph faster than either in cruise.

Design and development

American Airlines requested that Convair design an aircraft for coast-to-coast flights, able to fly nonstop New York to Los Angeles against westerly winds. They wanted somewhat larger passenger capacity than the 880, which was the smallest of the first-generation U.S. jet airliners. The 990 entered production in 1961.

One change from 880 was the addition of large anti-shock bodies on the upper wings to increase their critical Mach and reduce transonic drag. This allowed the heavier 990 to go slightly faster than the 880, cruising at about Mach 0.91, making it the fastest passenger jet when it was built. Originally, there were plans to use the bulges as fuel tanks, but during test flights the extra weight caused the tanks to vibrate excessively. Instead, the inner set of bumps also served a secondary role as fuel dump for the fuel tanks in the fuselage.

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 as found in the Pratt & Whitney JT3D that powered the 990's competitors. The engine was a simplified, non afterburning civilian version of the J79, used in military fighters. Like the J79, the CJ805 was very smoky.

Like the 880, 990s were later modified with a dorsal "raceway" added to the top of fuselage to hold the wiring for additional instrumentation.

Operational history

Early versions of the 990 did not meet the specifications promised to American Airlines, which reduced its order as a result. As a result, the 990A was developed by adding fairings to the engine nacelles, pylons and the lower surface of the wing. Convair and GE aerodynamicists designed these modifications using a local area rule. The resulting modifications significantly delayed the high-speed drag rise of the aircraft.^[1] Despite these modifications, the aircraft never did live up to its promise of coast to coast non stop capability westbound 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, having found the 707 and 720 more suited to its routes in spite of their larger capacity.

Swissair CV990A Coronado "St Gallen" at Manchester Airport in 1964

Swissair bought eight 990As from 1962 onwards, 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 points in the Far East.

The 990's market niche was soon to be captured entirely by the Boeing 727 and the Boeing 720 (a derivative of the 707), and by the time the line was 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 the Convair 880 and 990 to be accepted by the airlines led Convair to suffer what at the time were the largest corporate losses in history.

When the major airlines retired their Convair 990s, they found a second life operating for charter airlines. Spantax of Spain had a large fleet until they were gradually retired in the mid 1980s.

Several 990s have survived. A former Swissair Convair 990 is on display in the Swiss transportation museum, the Verkehrshaus in Luzern, while two are owned by the Mojave Spaceport. Of these, one is on display at the airport's entrance, and the other is used for movie and television filming projects.

Variants

• 990 : Initial production version.
• 990A : Faster cruising speed and longer range.^[2]

Operators

Interior of a Convair 990 operated by Swissair now on public display in the Swiss transport museum, the Verkehrshaus der Schweiz in Luzern.

NASA Convair 990. This aircraft has been retired, and is now on display at the entrance to the Mojave Spaceport.

• Aerolíneas Peruanas S.A.
• Air France
• Alaska Airlines
• American Airlines
• AREA Ecuador
• Cathay Pacific
• Ciskei International Airways
• Denver Ports of Call
• Garuda Indonesian Airways
• Internord
• Lebanese International Airways
• Middle East Airlines
• Modern Air Transport
• NASA
• Nomads Travel Club
• Nordair
• Northeast
• SAS
• Spantax
• Swissair
• Thai Airways International
• Varig / Real-Aerovias

Accidents and incidents

• December 3, 1972 — A Spantax Convair 990 crashed at Los Rodeos Airport on the island of Tenerife while taking off in almost zero visibility, killing all 7 crew and 148 passengers.
• April 12, 1973 — A U.S. Navy Lockheed P-3C (157332) operating from NAS Moffett Field in Sunnyvale, California collided with a Convair CV-990 (N711NA) operated by NASA during approach to runway 32R. The aircraft crashed on the Sunnyvale Municipal Golf Course, half a mile short of the runway, resulting in the destruction of both aircraft and the deaths of all aboard except for one Navy crewman.^{[3][N 1]}

Specifications (Convair 990)

General characteristics

• Crew: Four
• Capacity: 96 to 121 passengers
• Length: 139 ft 5 in (42.49 m)
• Wingspan: 120 ft (36.58 m)
• Height: 39 ft 6 in (11 m)
• Empty weight: 120,560 lb (54,690 kg)
• Loaded weight: 255,000 lb (115,700 kg)
• Powerplant: 4 × General Electric CJ805-23 turbofans, 16,100 lbf (71.6 kN) each

Performance

• Maximum speed: 534 knots (Mach .91) (615 mph, 990 km/h) at 22,000 ft (6,095 m)
• Cruise speed: 495 knots (570 mph, 920 km/h) at 35,000 ft (10,667 m)
• Range: 4,700 nm (5,400 mi, 8,690 km)
• Service ceiling: 41,000 ft (12,496 m)

See also

Related development

• Convair 880
  

Aircraft of comparable role, configuration and era

• Boeing 707
• Douglas DC-8
  

References

Notes

1. ^ Note that one Navy crewman in the P-3 did survive the crash. He was in the P-3's tail section, which broke off the aircraft as the 990 collided from above. He fell out of the broken tail section and survived with massive injuries. People at the golf course who witnessed the crash, tried to break open windows on the wreckage with golf clubs in a futile attempt to pull the injured out before fire consumed the crews.

Citations

1. ^ Kutney, John T. and Stanley P. Piszkin. "Reduction of Drag Rise on the Convair 990 Airplane". AIAA Journal of Aircraft, Vol. 1 No. 1, January-February 1964, pp. 8–12.
2. ^ "The Might-Have-Beens: Convair 880 and 990." Airliners.net. Retrieved: August 20, 2011.
3. ^ "Accident description: 12 APR 1973." Aviation Safety Network. Retrieved: August 20, 2011.

Bibliography

• Proctor, Jon. Convair 880 & 990. Miami, Florida: World Transport Press, 1996. ISBN 0-9626730-4-8.
• Taylor, John W. R. Jane's All The World's Aircraft 1965-66. London: Samson Low, Marston, 1965.
• Wegg, John. General Dynamic Aircraft and their Predecessors. London: Putnam, 1990. ISBN 0-85177-833-X.

External links

• Team Convair