Lockheed L-2000
| Lockheed L-2000 | |
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| Type: | Supersonic - airliner |
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| First flight: |
Never happened |
The Lockheed L-2000 was a draft of the Lockheed Corporation for a supersonic - airliner . The development took place in the 1960s in the course of a design competition by the US government.
history
prehistory
As early as 1956, the NACA (from 1958 NASA ) was convinced that it was technically feasible to build a large airliner that could fly over long distances at twice the supersonic speed. By then, the NACA had already done extensive theoretical engineering work for the Supersonic Commercial Air Transport (SCAT). At the 14th Technical Conference of the IATA in April 1961 in Montreal, the topic of a supersonic airliner was no longer just treated as a possibility, rather it was about when the numerous already existing concepts (e.g. the Convair model 58-9 ) were to be implemented can be. In March 1961, John F. Kennedy appointed FAA Administrator Najeeb Halaby to head a group that would deal with setting the framework for the implementation of a US supersonic airliner by the end of the decade. The final report submitted in September 1961 had a very optimistic tenor. According to Halaby, the research could have been completed in 1963 and the first flight of a machine would have been possible as early as 1967.
Kennedy then set up the Supersonic Transport Advisory Group (STAG) in November 1961 to take the lead in the American civilian supersonic program. The FAA was significantly represented here. At this time, the abbreviation SST appeared in American newspapers for the first time instead of the previously used SCAT. In the course of 1962, the FAA awarded research contracts to various American aircraft manufacturers, but no decisions have yet been made about a final concept. It was only as the Concorde continued to develop in January 1963 that Kennedy was forced to set up a cabinet-level commission headed by Lyndon B. Johnson to advance the SST program. The program was accelerated further after the President of Pan Am announced on June 4, 1963 that the company intended to procure six British / French Concorde.
Tender
On August 15, 1963, the FAA's Program Office formalized requests to the American aviation industry to submit proposals (Phase I) by January 15, 1964. The final selection of a winning design was scheduled for May 1, 1964. The tender called for a capacity of up to 160 passengers, a range of 4,000 mi (6,437 km), an altitude of over 40,000 ft (12,192 m) and a cruising speed of at least Mach 2.2. In order to resolve the concerns of Congress about high public subsidies, it was assured that manufacturers would have to bear at least 25% of the development and total manufacturing costs. The total government grants should not exceed one billion US dollars.
Phase I winners were Boeing's proposals ( Boeing Model 733 ) and the Mach-3 fast Lockheed L-2000. The Douglas 2229 , Convair Model 58-9 and the North American NAC-60 were rejected .
Concept phase
Lockheed initially examined three separate variants with passenger capacities between 170 and 250 people. The L-2000-1 version should be 62.23 m long, the L-2000-2 68.76 m and the L-2000-3 74.80 m. The span should always be 35.36 m.
At the end of May 1964, the FAA issued official Phase II development contracts to the two winners of the Phase I cell tender and to the competing engine manufacturers General Electric and Pratt & Whitney . The deadline for the final selection of the cell manufacturer was postponed from November 1964 to 1965, after which it was announced in July 1965 that the development contracts in a phase IIC were to be extended by 18 months. With the GE4, General Electric developed a civilian version of the YJ93 , which was tested on a North American XB-70 , while Pratt & Whitney proposed a completely new turbofan engine with the JTF17 .
Dummy construction
On June 26, 1966 was roll-out of full-scale dummy instead of the L-2000-7 in Burbank. This variant now had a length of 83.21 m. The engine manufacturers, however, were able to present functional versions; The GE4 delivered a thrust of 234 kN on October 28, 1966. Pratt & Whitney's JTF17 even reached 254 kN on December 11 of the same year, making it the most powerful civil engine outside the Soviet Union.
Phase IIC ended by President Johnson on New Years Day 1967 with the announcement of the Boeing 2707 as the winner of the SST competition. This meant the end of the project for the L-2000. The GE4 was declared the winner of the engine tender.
Construction features of the dummy
The L-2000 had a double-delta wing layout that Lockheed had already used in a similar form with the A-12 / SR-71 family. This should allow angles of attack of up to 35 °. For the take-off and landing phase, the fuselage tip could be lowered by 15 °. The fuselage diameter of 3.45 m allowed 3 + 2 seating with a central aisle. The two main landing gear units each had six tires, the nose landing gear had two tires.
Technical specifications
| Parameter | Data |
|---|---|
| crew | 3 |
| Passengers | at least 226 |
| length | 83.21 m (L-2000-7) |
| span | 35.36 m |
| payload | 25,000 kg over 6400 km |
| Max. Takeoff mass | 250,000 kg |
| Cruising speed | at least Mach 2.7 in 20,000 m |
| Runway length | 1980 m |
| Runway length | 2075 m |
Web links
- THE UNITED STATES SST CONTENDERS. Flight International , February 13, 1964, accessed September 24, 2016 .
- MACH THREE TECHNOLOGY. Flight International , January 20, 1966, accessed September 24, 2016 .
literature
- Lockheed L-2000 SST . In: Flug Revue September 1966, pp. 27–29
- Bill Yenne: America's Supersonic Transport - Commercial Pioneers . In: Flightpath Vol. 3, 2004, pp. 146–157