Lockheed L-1011 TriStar

Lockheed L-1011 TriStar
Name	Lockheed L-1011 TriStar
Caption	A Delta Air Lines L-1011-1 in flight, 1974.
Type	Wide-body trijet airliner
National origin	United States
Manufacturer	Lockheed Corporation
First flight	November 16, 1970
Introduction	April 26, 1972 with Eastern Air Lines
Status	In limited service
Primary users	Delta Air Lines (historical), Eastern Air Lines (historical), Trans World Airlines (historical), Royal Air Force
Produced	1968–1984
Number built	250
Unit cost	$20 million (1972)

Lockheed L-1011 TriStar. The Lockheed L-1011 TriStar is a medium-to-long-range, wide-body trijet airliner developed and manufactured by the Lockheed Corporation between 1968 and 1984. It was one of the second generation of wide-body jets, competing directly with the McDonnell Douglas DC-10 and, later, the Airbus A300. Renowned for its advanced fly-by-wire control system and sophisticated Autoland capability, the TriStar was considered one of the most technologically advanced airliners of its era, though its commercial success was hampered by financial difficulties at Lockheed and market competition.

Development and design

The program was launched in 1968 following a pivotal order from Eastern Air Lines and was heavily influenced by the requirements of American Airlines. The design centered on the advanced Rolls-Royce RB211 turbofan engine, a decision that led to severe financial strain for both Rolls-Royce Limited and Lockheed Corporation when the engine's development encountered major cost overruns and technical delays, requiring a rescue package from the British government. The aircraft incorporated numerous innovations, including a unique Direct Lift Control system and one of the first commercial applications of a fly-by-wire system for its secondary flight controls. Its distinctive S-duct for the center engine, which ingested air through an intake at the base of the vertical stabilizer, contributed to a quieter passenger cabin compared to its rivals.

Operational history

The TriStar entered service with Eastern Air Lines on routes from Miami to New York City in 1972, followed shortly by Trans World Airlines. Delta Air Lines became the largest operator, eventually building a substantial fleet that served its domestic and international network for decades. While praised by pilots and passengers for its smooth ride and advanced systems, sales were ultimately limited to 250 aircraft, in part due to the protracted development and the dominance of the McDonnell Douglas DC-10 in the market. The type saw extensive use on transcontinental routes across the United States and on long-haul flights to destinations like London and Tokyo. Military derivatives were also developed, most notably the VC-10 and tanker variants for the Royal Air Force.

Variants

The initial production model was the L-1011-1, optimized for domestic U.S. routes. The longer-range L-1011-200, introduced in 1976, featured more powerful Rolls-Royce RB211 engines for hotter climates and was operated by carriers like Saudia and Gulf Air. The definitive L-1011-500 was a substantially modified, long-range version with a shortened fuselage, increased wing span, and increased fuel capacity, entering service with British Airways in 1979. Specialized variants included the L-1011-50 which added a fuel tank in the belly fairing, and military conversions such as the Royal Air Force's Tristar K1 and KC1 tanker/transports, modified from used civilian airframes.

Operators

Major civil operators throughout its history included Delta Air Lines, Eastern Air Lines, Trans World Airlines, British Airways, Pan American World Airways, and All Nippon Airways. In the Middle East, Saudia and Gulf Air were significant customers. The primary military operator is the Royal Air Force, which acquired a fleet of converted aircraft for strategic transport and aerial refueling roles. Following retirement from major passenger service, many airframes were used by charter carriers like Focus Air and Orion Airways, while others were converted into freighter aircraft for cargo operators.

Accidents and incidents

The TriStar has been involved in several notable accidents. In 1972, Eastern Air Lines Flight 401 crashed into the Florida Everglades due to crew distraction, resulting in significant changes to crew resource management training. A Saudia TriStar was destroyed in 1980 by a fire after an emergency landing at King Khalid International Airport. The deadliest incident occurred in 1985 when Delta Air Lines Flight 191 crashed during a microburst-induced wind shear on approach to Dallas/Fort Worth International Airport, killing 137 people. In 1998, a Trans World Airlines L-1011 experienced a severe center engine failure, leading to an emergency landing at John F. Kennedy International Airport.

Aircraft on display

Several retired TriStars are preserved in museums worldwide. A former Eastern Air Lines L-1011-1 is on display at the Fantasy of Flight museum in Polk City, Florida. The Museum of Flight in Seattle houses the first production aircraft. In the United Kingdom, a Royal Air Force TriStar K1 is part of the collection at the Royal Air Force Museum Cosford. Other preserved examples can be found at the Delta Flight Museum in Atlanta and the Yanks Air Museum in Chino, California.

Category:Airliners Category:Trijet aircraft Category:United States airliners 1960–1969