Lockheed L-2000

The Lockheed L-2000 was Lockheed's entry in a government-funded competition to build the United States' first supersonic transport (SST) in the 1960s. The L-2000 lost the contract to the Boeing 2707, but this design was also ultimately cancelled for environmental and economic reasons.

In 1961, President John F. Kennedy committed the government to subsidizing 75% of the development of a commercial airliner to compete with Anglo-French Concorde then under development. The director of the Federal Aviation Administration, Najeeb Halaby, elected to improve upon the Concorde's design rather than compete head-to-head with it. The SST, which represented a significant advance over the Concorde, was intended to carry 250 passengers (a large number at the time), fly at Mach 2.7-3.0, and have a range of 4,000 miles.

The program was launched on June 5, 1963, and the FAA estimated that by 1990 there would be a market for 500 SSTs. Boeing, Lockheed, and North American officially responded. North American's design was soon rejected, but the Boeing and Lockheed designs were selected for further study.

Early design studies

Like Boeing, Lockheed had done a number of "paper studies" on various SST designs since the 1950s. Early designs followed Lockheed's unique high-speed design, which used a short—almost rectangular—wing, as opposed to the swept wings or delta wings favored by most other designers. (Take the wing of the F-104 Starfighter for example.)

Starting with the Blackbird, however, Lockheed began moving toward delta wings. The SST paper studies followed suit, leading to the delta winged L-2000 series. A number of similar designs were studied at a range of sizes and passenger capacities, from the 170-seat 2000-1, to the 250 seat 2000-3 and 2000-7. All of these designs used a 2 by 3 seating arrangement, slimmer than the more common 3 by 3 found on other "narrow body" airliners of the era.

Design competition

During the period between 1963 and 1966, the design took on its final form as the L-2000-7B. It was, for all intents, a larger version of Concorde. The differences tended to be in the details: Lockheed used a simpler compound-delta planform instead of Concorde's more complex ogive, and the Pratt & Whitney JTF17 engines were mounted in individual cylindrical nacelles with a vertical splitter into the shock ramps, instead of the Concorde's box-like nacelles with horizontal intake ramps. The L-2000 also had a prominent "belly" for fuel and cargo, with the main fuselage sitting somewhat higher over the wing than on other designs.

On December 31, 1966, full-scale mockups of the Boeing 2707-200 and L-2000-7 design were presented to the FAA, and the Boeing design was selected. The L-2000 was judged simpler to produce and less risky, but its performance was slightly lower and its noise levels slightly higher. The Boeing design was considered more advanced, representing a greater lead over the Concorde and thus more fitting to the original design mandate. Ironically, Boeing eventually changed its advanced variable-geometry wing design to a more simple delta-wing similar to Lockheed's design. The American SST project was cancelled in 1971.

Specifications (L-2000-7A)

General characteristics

• Crew:
• Capacity: 273 passengers
• Length: 273 ft 2 in (83.26 m)
• Wingspan: 116 ft (35.36 m)
• Height: ()
• Wing area: 8,486 ft² (778.378 m²)
• Empty weight: 238,00 lb (107,955 kg)
• Max takeoff weight: 590,000 lb (276,620 kg)
• Powerplant: 4× GE4/J5M or Pratt & Whitney JTF17A-21L , () each

Performance

• Cruise speed: Mach 2.7 ()
• Range: 4,000 mi (6,435 km)
• Service ceiling: 70,000 ft (21,375 m)