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Lockheed L2000 SST

In the early 1960s, fearful about being left behind in the SST race, the U.S. government asked its aerospace companies to submit a design to compete with Europe's future Concorde. On June 5, 1963 in a speech before the graduating class of the United States Air Force Academy, President Kennedy committed this nation to "develop at the earliest practical date the prototype of a commercially successful supersonic transport superior to that being built in any other country in the world ...." What lay ahead was years of development, competition, controversy, and ultimately rejection of the supersonic transport (SST) by the United States, and it remains to be seen whether the British-French Concorde or Russian TU-144 designs will prove to be economically feasible and acceptable to the public.

NASA did considerable work, starting in 1959, on basic configurations for the SST. There evolved four basic types of layout which were studied further by private industry. Lockheed chose to go with a fixed-wing delta design; whereas, Boeing initially chose a swing-wing design.

The initial design concept called for a 400,000-1b titanium airplane capable of flying at Mach 2.7 with a range of at least 4000 nautical miles and a capacity of 125 to 160 passengers. Design proposals were received in January 1964 from three aircraft manufacturers (Lockheed, Boeing, and North American Aviation) and three engine companies (Pratt & Whitney, Curtiss-Wright, and General Electric). In May 1964 contracts were awarded to Boeing and Lockheed for further studies of the airplane design and to General Electric and Pratt & Whitney for additional work on the engine. One problem associated with the SST is the tendency of the nose to pitch down as it flies from subsonic to supersonic flight. The swing-wing can maintain the airplane balance and counteract the pitch-down motion. Lockheed needed to install canards (small wings placed toward the airplane nose to counteract pitch down. Eventually, the Lockheed design used a double-delta configuration and the canards were no longer needed. This design proved to have many exciting aerodynamic advantages. The forward delta begins to generate lift supersonically (negating pitch down). At low speeds the vortices trailing from the leading edge of the double delta increase lift. This means that many flaps and slats could be reduced or done away with entirely and a simpler wing design was provided. In landing, the double delta experiences a ground-cushion effect which allows for lower landing speeds. This is important since three-quarters of the airplane accidents occur in take-off and landing.The British-French Concorde and the Russian TU-144 used a variation of the double delta wing called the ogee wing. It, too, uses the vortex-lift concept for improvement in low-speed subsonic flight.

The Lockheed Model 2000 was of a double-delta design to be powered by four General Electric GE4/J5 or Pratt And Whitney JTF17A turbojet engines installed in individual ducts under the rear of the wings. The Lockheed Model 2000 was designed to carry between 258 and 273 passengers in five-abreast seating over distances of at least 6440 km at a cruising speed of Mach 2.7. A mock-up model was completed in mid-1966, complete with a replica of the flight deck and full furnished passenger accommodation. Like the Concorde, the Lockheed Model 2000 also had a nose which could be drooped.

The final version - the L-2000-7 - was considerably enlarged in size. It was projected to compete with the second generation of airliners with increased passenger capacity - Boeing 747, DC-10, L-1011 - and Lockheed could not remain aside. The L-2000-7a reached a length 83,2 m, and its large sister, the L -2000-7b, was lengthened to 89,4 m (only on 4 m less than the enormous Boeing 2707). The tail assembly was altered for reduction in the drag, and for increasing the longitudinal stability small ventral fin was added. Lift-drag ratio L -2000-7 by [M]=3 grew to 8. With the identical maximum takeoff weight of 267 tons the L -2000-7a it could transport 230 passengers in two classes to a range of 4000 miles, and the L-2000-7b about 250 to a range of 3000-3500 miles.

In June 1966 a full-scale mock-up of the L-2000-7 was presented in Burbank, California. However, in the middle of summer, Boeing presented the radically revised B-2707-100 SST design. Although its speed was less, the passenger capacity grew to 300 in the standard international trip, and could transport 29.5 tons, rather more than L-2000. For the first time lift-drag ratio of Boeing at cruising speed exceeded that of the Lockheed design - 8.2 against 8. Moreover, the variable sweep wing showed itself considerably better at subsonic speed.

On 06 September 1966 the competing projects were represented in the FAA. In the course of four months the representatives of the government, airlines and even the President of the United States evaluated the SST projects. And on 31 December 1966, the FAA recognized the Boeing 2707-100 the winner. The Lockheed L-2000 program was ended. Contracts were awarded to Boeing to build the airframe and to General Electric to produce the engine. Design problems with the airframe and engine, coupled with fears about environmental and economic effects, led to the cancellation of the SST program in May 1971, after 8 years of research and development.

One analyst, Rene J. Francillon, has concluded that, "geopolitical considerations" may well have been the decisive factor in awarding three equally large contracts in 1965 and 1966. Francillon identified the three potential contracts. Douglas and Lockheed in California, and Boeing in the state of Washington competed for the Manned Orbiting Laboratory (MOL) and the Supersonic Transport (SST). Boeing and Douglas, joined by Lockheed-Georgia rather than Lockheed's West Coast operation, went after the C-5A. Each of the parent firms got one of the three: Douglas and the state of California won the MOL contract; Boeing and the state of Washington received the SST; and in October 1965 Lockheed- Georgia became prime contractor for the C-5. This last award came at a critical time because C-141 production was coming to an end, threatening to shut down the enormous, government-owned Marietta plant, which Lockheed leased, and deliver a damaging economic blow to the state of Georgia. Whatever the merits of Francillon's analysis, the two West Coast contractors suffered unexpected setbacks, for both the MOL and SST contracts were subsequently canceled.

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Page last modified: 07-07-2011 02:33:54 ZULU