Lockheed L-1011 TriStar
The Lockheed L-1011 TriStar is an American three-engine wide-body airliner developed by Lockheed Corporation. Introduced in 1972, it was known for a quiet cabin, advanced automatic flight controls and the Rolls-Royce RB211 turbofan.[1]
Development
Lockheed developed the TriStar for the same medium- and long-range market as the McDonnell Douglas DC-10. The programme depended on the new RB211 engine; Rolls-Royce's financial collapse and government-backed rescue delayed the aircraft. The prototype flew on 16 November 1970, and Eastern Air Lines introduced it on 26 April 1972.[1]
Lockheed built 250 aircraft between 1968 and 1984. The initial L-1011-1 was followed by higher-weight -100 and -200 versions and the shorter, longer-range -500. Insufficient sales prevented the programme from recovering its development costs, and the TriStar became Lockheed's final commercial airliner.[1]
Design
The L-1011 uses two underwing engines and a third engine in the tail, fed by an S-shaped intake. It introduced highly capable automatic flight and landing systems, a four-channel autopilot and direct-lift control. Some airline layouts used a below-deck galley reached by lifts.[1][2]
The wide cabin could accommodate up to about 400 passengers at high density, while typical multi-class layouts carried fewer. Long-range variants combined additional fuel and higher weights with the efficient RB211.
Operations and legacy
Major operators included Eastern Air Lines, Trans World Airlines, British Airways, Delta Air Lines and Cathay Pacific. Airline service has ended, and surviving aircraft are mostly preserved or stored. A modified L-1011 named Stargazer remains in specialist use as an airborne launch platform for Pegasus rockets.[1]
Lockheed Martin describes the TriStar as the first commercial airliner capable of automatic flight from takeoff through landing. Its engineering reputation outlasted its commercial failure, and the type remains a landmark of 1970s wide-body design.[2]