The Lockheed L-1011 TriStar was the third widebody passenger jet airliner to reach the marketplace, following the Boeing 747 "jumbo jet" and the Douglas DC-10. In the 1960s, American Airlines approached Lockheed and competitor Douglas with a need for an aircraft smaller than the existing 747, but still capable of flying to distant locales such as London, the Caribbean, and Latin America from company hubs in Dallas/Ft Worth and New York. Lockheed answered the call with the TriStar. Perhaps ironically, American never flew the "Ten Eleven," purchasing many DC-10s instead.

First flown on November 16, 1970, the twin-aisle TriStar was considered a technological marvel of its day, featuring low noise emissions, improved reliability, and efficient operation. The main visible difference between the TriStar and DC-10 is in the middle/tail engine; the DC-10's engine is external for more power, while the TriStar's engine is integrated into the tail through an S-duct for quietness and stability. Although the TriStar's design schedule closely followed that of its fierce competitor, the DC-10, Douglas beat Lockheed to market by a year due to delays in power plant development. Rolls-Royce, the maker of the TriStar's RB211 turbofan engines, had filed for bankruptcy, halting L-1011 final assembly. The British government did not approve the large state subsidy used to restart Rolls-Royce operations until after the U.S. government had guaranteed the Lockheed loans previously provided to Rolls for the extensive engine contract. The first TriStar was finally delivered to Eastern Airlines on April 26, 1972.

Designed for a maximum seating of 400 passengers, the TriStar utilized a new engine layout: in addition to Rolls-Royce turbofan jet engines on each wing, a third engine was located dorsally below the vertical stabilizer. Manufactured in Lockheed facilities in Palmdale, California, the TriStar faced brisk competition with the Boeing 747 and, even more directly, the Douglas (later McDonnell Douglas) DC-10, which it closely resembled. The TriStar had a better safety record than the DC-10, and Trans World Airlines heralded the TriStar as one of the safest airplanes in the world in some of its promotional literature in the 1980s when concern over the safety record of the DC-10, which was flown by most of its competitors, was at its peak. However, the DC-10 outsold the TriStar nearly two to one, partly because of the TriStar's delayed introduction.

Nevertheless, a number of airlines flew the TriStar, including Aer Lingus, Air Atlanta Icelandic, Air Canada, Air Lanka, All Nippon Airways, Arrow Air, British Airways, BWIA, Cathay Pacific, Court Line, Delta Air Lines, Eastern Airlines, Fine Air, Gulf Air, Hawaiian Airlines, Iberia Airlines (1 example), LTU, National Airlines, Pan Am, Peach Air, PSA, TAP Air Portugal Trans World Airlines, United Airlines (acquired in the Pan Am buyout), Royal Jordanian and Saudi Arabian Airlines. The aircraft's largest operator, Delta Air Lines, retired its TriStar fleet in 2001, replacing them with the Boeing 767-400ER. TWA withdrew its last TriStar from service in 1997.

Lockheed bribed the Japanese government to subsidize ANA's purchase of L-1011's, and the resulting political scandal led to the arrest of Prime Minister Tanaka Kakuei.

A longer-range variant of the standard-length L-1011 was developed in the late 1970s. Designated the L-1011-500, the fuselage length was shortened by 14 feet (4.3 m) to accommodate higher fuel loads.

Lockheed manufactured a total of 250 TriStars, ceasing production in 1984. Lockheed needed to sell 500 planes to break even. Failing to achieve profitability in the civilian airliner sector, the TriStar was to be Lockheed's last commercial aircraft. Airlines played Douglas and Lockheed off each other, driving the prices of both planes down, and the end result was Douglas' merger with McDonnell and Lockheed's departure from the commercial aircraft business.

The aging L-1011 was still in use by some airlines at the start of the 21st century, and in the late 1990s, NASA performed aerodynamic research on modified L-1011s.

Military service
The Tristar has also been used as a military tanker and cargo aircraft. The British Royal Air Force has nine aircraft of four variants in service at the moment. The aircraft are ex-British Airways and Pan Am L-1011-500s. Two of the aircraft are designated K1's and are pure tankers. Another four are KC1's and can be either tankers or cargo aircraft. The two C2 models and the solitary C2A are pure cargo aircraft. The C2A differs from the C2 by having military avionics and radios. The RAF's Tristars were bought in the immediate aftermath of the Falklands War to bolster the long range capability of the RAF in the transport and tanker arenas. All of the aircraft serve with No. 216 Squadron, based at RAF Brize Norton.

The aircraft have seen service in many recent conflicts. Two were deployed to King Khalid International Airport, near Riyadh in Saudi Arabia during the 1991 Gulf War as tankers, with the rest used for transport between the Persian Gulf and UK. The two aircraft deployed received nose art naming them Pinky and Perky. During the 1999 Kosovo War, Tristars deployed to Ancona in Italy, again as tankers, with four aircraft involved. Tristars joined VC-10s in the AAR role for Operation Veritas (Afghanistan,) during which they provided aerial-refuelling for US Navy aircraft. Their most recent wartime role was again over the skies of Iraq. The RAF deployed four Tristars during Operation Telic, to an as-yet-undisclosed location.

Orthographic diagrams of L-1011 exteriorThe Tristar is expected remain in service with the RAF until the end of this decade, when it is scheduled to be replaced by the Airbus A330 MRTT under the Future Strategic Tanker Aircraft (FSTA) programme. The Airtanker consortium, lead by EADS, won the FSTA contract in January 2004. However beginning in April 2004 there have been continuing rumours about the fragile state of the contract negotiations. This culminated in an ultimatum by the UK's Defence Procurement Agency, delivered to EADS, demanding a reduced price for the aircraft. With continuing doubts over the FSTA programme Marshall Aerospace, responsible for the conversion of the RAF's original Tristars, have offered to buy and convert some of the large number of surplus commercial Tristars. This would give the UK a much needed increase in capacity (with the upcoming retirement of the VC-10 fleet) at a fraction of the cost of the £13Bn FSTA project.

-280 seats
-590 mph
-248 tons max. gross take-off weight
-6000 mile range
-3 Rolls Royce RB211 Engines (50,000lb thrust)
-164ft Length
-55ft Height
-155ft Span

First flight November 16, 1970.
Entered service August 5, 1972.
Went out of service in 1986.