Lockheed L-1011 Tristar 100

The Lockheed L-1011-100 TriStar is the second production model of the L-1011 TriStar, Lockheed’s wide-body trijet airliner. It kept the original TriStar 1 airframe and engines, but added a center fuel tank and a higher maximum takeoff weight that stretched its range by nearly 930 miles (1,500 km).

Lockheed built 250 TriStars of all versions between 1968 and 1984, and the program’s failure to turn a profit pushed the company out of the airliner business. The only TriStar known to remain in service, Northrop Grumman’s rocket-launching Stargazer, is a TriStar 100.

Where the TriStar 100 fits in the L-1011 family

The name is pronounced “L-ten-eleven,” and Lockheed’s internal model number for the design was L-093. Every TriStar has three Rolls-Royce RB211 turbofans: one under each wing and a third buried in the tail, fed by an S-shaped duct from an intake on top of the fuselage.

The long-fuselage family runs from the original TriStar 1 through the heavier TriStar 100 and the TriStar 200, which swapped in more powerful RB211-524B engines. The TriStar 50 and 150 were weight upgrades for existing TriStar 1s, and the TriStar 250 was a conversion that only Delta carried out, on six late TriStar 1s.

The TriStar 500 is the odd one out: its fuselage is 14 ft (4.3 m) shorter, for longer range, and it first flew on October 16, 1978.

Spotters can separate the early models from the rest by the center engine. The TriStar 1, 100 and 150 have a plain round intake, while later TriStars add a small vertical fin between the bottom of the intake and the top of the fuselage.

How Lockheed developed the TriStar

In the 1960s American Airlines asked Lockheed and Douglas for an airliner that could carry 250 passengers on transcontinental routes. Lockheed had not built a civil airliner since the L-188 Electra turboprop, but the C-5 Galaxy military transport had given it experience with very large jets and high-bypass turbofans.

Douglas answered with the DC-10, a trijet of similar size, and American bought it. Where McDonnell Douglas ran the DC-10 on a firm budget, Lockheed packed the TriStar with the most advanced technology of the day to cut noise, improve reliability and burn less fuel.

The biggest bet was the engine. Lockheed chose the Rolls-Royce RB211, a new three-shaft turbofan originally designed around a carbon-fiber fan, as the TriStar’s only powerplant, while the DC-10 used General Electric’s CF6.

The prototype first flew on November 16, 1970. In February 1971, crushed by the cost of developing the RB211, Rolls-Royce went into receivership, and TriStar final assembly stopped.

The British government agreed to rescue Rolls-Royce only if the US government guaranteed the bank loans Lockheed needed to finish the TriStar. Lockheed secured $250 million in loan guarantees after a narrow vote in Congress, according to Simple Flying.

The FAA certified the TriStar on April 14, 1972, and it entered service with Eastern Air Lines that month, a year behind the DC-10. It was the third wide-body airliner in service after the Boeing 747 and the DC-10, and Eastern nicknamed it the “Whisperliner.”

What the TriStar 100 changed

The TriStar 1 was designed for short- and medium-range routes, and airlines with longer sectors wanted more fuel and more weight. Lockheed delivered both in two steps in 1975, each recorded on the FAA type certificate.

The L-1011-385-1-14, approved on June 6, 1975, raised the weights but kept the original fuel system. The L-1011-385-1-15, approved on July 25, 1975, added the center tank that defines the TriStar 100, and the FAA lists every -1-14 as since converted to -1-15 standard.

The center tank sits between the wing halves in two parts, and each half acts as extra capacity for its neighboring inboard wing tank. On the type certificate it adds 18,800 lb (8,530 kg) of usable fuel, roughly 2,800 US gallons (10,600 L).

Maximum takeoff weight rose from the TriStar 1’s 430,000 lb (195,000 kg) to 466,000 lb (211,400 kg). Together the tank and the higher weights added nearly 930 miles (1,500 km) of range, and the engines did not change: the TriStar 100 kept the TriStar 1’s RB211-22B.

Saudia and Cathay Pacific placed the launch orders for the TriStar 100, two aircraft each, in May 1974, and deliveries began in June 1975. TWA, Air Canada and BEA, which merged with BOAC to form British Airways, also bought the model for longer routes.

The TriStar 200 followed in 1976 with the same airframe, fuel and weights, but RB211-524B engines of about 50,000 lbf for better performance at hot and high airports. Saudia launched it, and Gulf Air used it to replace its Vickers VC10s.

Cockpit, autoland and systems

Three people fly the TriStar: a pilot, a copilot and a flight engineer, the minimum crew on its FAA type certificate. Its autopilot, part of an Automatic Flight Control System, was unusually advanced for 1972.

On May 25, 1972, Lockheed test pilots flew a TriStar from Palmdale, California, to Dulles Airport outside Washington with that system engaged from the takeoff roll to landing. Lockheed Martin calls it the first cross-country flight without human hands on the controls.

The type certificate approves automatic landing down to Category IIIA weather minima. A direct lift control system also deployed wing spoilers automatically to hold the jet on the glideslope without large pitch changes, which made for smoother approaches.

Instead of the trimmable horizontal stabilizer most jets of the time used, the TriStar has an all-moving tail, which Lockheed chose to eliminate mis-trim and runaway-trim problems. It also carries four independent 3,000 psi hydraulic systems, where most contemporaries had three.

The flight management system, certified in September 1977, added features that later became common, including a descent mode that worked back from a chosen point to find where to start down and arrive on altitude and on speed.

Cabin and seating

The TriStar has a twin-aisle cabin, and TWA’s economy class used a 2-5-2 layout. Airlines usually fitted around 256 seats in two classes.

The 400 seats in the specification table is the certificated maximum, ten abreast. The FAA allows 400 passengers with four full-size Type A doors per side, and 345 when one door on each side is a smaller Type I exit.

The design also offered lower-deck galleys. Pacific Southwest Airlines ordered two TriStar 1s with built-in airstairs leading into an entry hall in the forward lower hold, so they could board passengers at airports without jet bridges.

Explaining the numbers

The full specification table for the aircraft is on this page. A few of its figures need context, because the TriStar 100 sits between variants that published sources cover more fully.

Range is the main one. The 3,600 nautical miles (4,140 miles) in the table is the figure Jane’s gives for the TriStar 200 with a full load of passengers and bags, and the TriStar 200 shares the TriStar 100’s weights and fuel.

For comparison, Jane’s lists 2,680 nm for the TriStar 1. The range of more than 4,000 nm quoted in many summaries of “the TriStar” belongs to the long-range TriStar 500, which Jane’s puts at 5,345 nm.

The speed row shows 539 knots (620 mph, 998 km/h), the maximum speed Jane’s lists for every TriStar variant it tabulates, measured at 26,200 ft. The type certificate limits the jet to Mach 0.90, and EUROCONTROL’s planning data puts a typical cruise at about Mach 0.86.

The 43,000 ft ceiling comes from the TriStar 100’s certification as an L-1011-385-1-15. The FAA lists 42,000 ft for the TriStar 1 and 43,000 ft for the -1-15 and the TriStar 500.

Thrust is listed as 42,000 lbf per engine, the figure usually quoted for the RB211-22. The type certificate gives the RB211-22B a takeoff rating of 41,030 lb, or 42,670 lb with a later Rolls-Royce modification.

Why the L-1011 failed commercially

The TriStar was a technical success and a financial failure. Lockheed needed to sell 500 to break even and sold 250, against more than 400 DC-10s.

Engine delays put it a year behind the DC-10, and it lost ground again on long-haul routes. General Electric quickly found more thrust in the CF6, which let McDonnell Douglas bring the intercontinental DC-10-30 to market, while the higher-thrust RB211-524 took Rolls-Royce many years.

Scandal made things worse. In 1976 it emerged that Lockheed had secretly bribed Japanese officials over All Nippon Airways’ TriStar purchase, which led to the arrest of former Prime Minister Kakuei Tanaka and the resignations of Lockheed’s chairman and president.

In late 1981 Lockheed announced that production would end with the 250th TriStar, delivered in 1984, and it left the commercial airliner business. Lockheed Martin still describes the TriStar as the company’s last commercial passenger airliner.

The trijet layout was also running out of time. As ETOPS rules let twin-engine wide-bodies such as the Boeing 767 and Airbus A330 fly longer overwater routes, three-engine jets became too costly to operate. McDonnell Douglas, also weakened, could only refine the DC-10 into the MD-11.

Airlines that flew the TriStar

Delta Air Lines was the largest TriStar customer. The Delta Flight Museum counts 70 TriStars across five variants in Delta’s fleet, up to 56 at one time, and says Delta was the only major airline to fly all five.

Delta flew its first TriStar service on December 15, 1973, and its last on July 31, 2001, replacing the type with the Boeing 767-400ER.

Cathay Pacific became the largest non-US operator, flying as many as 21 TriStars after buying many of Eastern Air Lines’ aircraft, and retired them in October 1996 in favor of the Airbus A330-300. TWA retired its last TriStars in September 1997.

The last scheduled TriStar passenger flights ended in 2007 and 2008, with Brussels Airlines (on a codeshare with Hewa Bora Airways), Thai Sky Airlines and Lloyd Aéreo Boliviano. In its later years the type flew mostly with charter and wet-lease operators, particularly in Africa and Asia.

The Royal Air Force flew nine TriStars as tankers and transports with No. 216 Squadron at RAF Brize Norton. They flew their last sorties on March 24, 2014, and were replaced by the Airbus A330 MRTT.

Stargazer: the TriStar 100 that launches rockets

Stargazer is TriStar serial number 1067. It first flew on February 22, 1974, and entered service with Air Canada as C-FTNJ that March, and the FAA type certificate lists serial 1067 among its -1-15 aircraft.

Orbital Sciences bought the stored airframe in May 1992 and had Marshall Aerospace in the UK modify it to carry the Pegasus, an air-launched orbital rocket. It flew its first Pegasus mission on June 27, 1994, the maiden flight of the Pegasus XL.

In 2010 it was re-engined with RB211-524 turbofans of about 50,000 lbf, replacing its original RB211-22s. It can carry a 51,000 lb (23,100 kg) payload to 42,000 ft.

Its most recent launch came on July 3, 2026, when it released a Pegasus XL at about 40,000 ft over Kwajalein Atoll in the Marshall Islands. The rocket carried Katalyst Space’s LINK spacecraft, built to raise the orbit of NASA’s Swift observatory.

SpaceNews described that mission as potentially the final flight of the Pegasus. Whether Stargazer keeps flying after Pegasus is the open question for the whole type, since it is the only TriStar still listed in service.

Safety record and notable accidents

Aviation Safety Network’s database, as cited on Wikipedia, counted 35 TriStar incidents as of December 2011, including 10 hull-loss accidents and 540 fatalities.

Eastern Air Lines Flight 401 crashed into the Florida Everglades on December 29, 1972, killing 101, after the crew failed to monitor the flight instruments while dealing with a faulty landing-gear indicator. It was the first fatal TriStar crash, eight months after the type entered service.

The deadliest TriStar accident was Saudia Flight 163 on August 19, 1980. After a fire broke out in the rear of the TriStar 200 and the crew landed at Riyadh, delays in starting the evacuation led to the deaths of all 301 people aboard.

Delta Air Lines Flight 191 crashed on approach to Dallas/Fort Worth in a microburst on August 2, 1985. Eight of 11 crew members and 128 of 152 passengers died, along with one person on the ground.

On May 3, 1986, a bomb in the rear cargo hold of Air Lanka Flight 512 destroyed a TriStar on the ground at Colombo, killing 21.

Other crews saved badly damaged TriStars. On Delta Flight 1080 in 1977, a jammed left stabilizer nearly overpowered the flight controls, and the captain reached Los Angeles by steering with engine thrust.

In 1992 all 292 people aboard TWA Flight 843 escaped with only minor injuries after an aborted takeoff at JFK, before fire destroyed the aircraft.

Where to see a TriStar today

The Delta Flight Museum in Atlanta displays a 65 ft (19.8 m) section of the prototype’s fuselage, serial 1001, running from the cockpit back to the wing. Delta salvaged it from Ardmore, Oklahoma, in 1989, and it sits indoors in Historic Hangar 2 in the airline’s classic widget livery.

In Riyadh, a former Saudia TriStar 200 stands as a gate guardian at the Royal Saudi Air Force Museum.

One TriStar went underwater. A former Royal Jordanian TriStar 500 became part of the Underwater Military Museum dive site at Aqaba, Jordan, on August 26, 2019.

Frequently Asked Questions

Are any L-1011s still flying?

One is known to be. Northrop Grumman’s Stargazer, a TriStar 100, launched a Pegasus XL rocket over Kwajalein Atoll on July 3, 2026. SpaceNews called that mission potentially the Pegasus rocket’s final flight, so whether the aircraft keeps flying is unresolved.

Why did the L-1011 fail?

Rolls-Royce’s collapse in 1971 put the TriStar a year behind the DC-10, and the higher-thrust engine for a long-range version took years more. Lockheed needed 500 sales to break even, sold 250, and then left the airliner business.

Was the L-1011 a good plane?

As an aircraft, yes. It was quiet, technically advanced and certificated for automatic landing in Category IIIA weather, and Lockheed Martin says the fleet’s in-service reliability rate reached 98.1 percent. Its failure was commercial.

How many L-1011s have crashed?

Aviation Safety Network’s database, as cited on Wikipedia, recorded 10 hull-loss accidents among 35 TriStar incidents as of December 2011. The deadliest was Saudia Flight 163 in 1980, in which all 301 people aboard died.

How many L-1011 TriStars were built?

Lockheed built 250 TriStars of all versions between 1968 and 1984, in Burbank and Palmdale, California. That was half the 500 it needed to break even.

What is the difference between the L-1011-1 and the L-1011-100?

The TriStar 100 has the same fuselage, wing and RB211-22B engines as the TriStar 1, but adds a center fuel tank and raises maximum takeoff weight from 430,000 lb to 466,000 lb. Together those changes added nearly 930 miles (1,500 km) of range.

How many passengers does the L-1011-100 carry?

Airlines typically seated about 256 passengers in two classes. The FAA certificates the long-fuselage TriStar for up to 400 passengers, ten abreast, when it has four Type A doors per side.

What engines does the L-1011 TriStar use?

Only Rolls-Royce RB211 turbofans. The TriStar 1 and 100 use the RB211-22B, usually quoted at 42,000 lbf, while the TriStar 200 and 500 use the RB211-524B of about 50,000 lbf.

How is the L-1011 different from the DC-10?

Both are three-engine wide-bodies of similar size. The TriStar’s center engine sits inside the tail, fed by an S-shaped duct, while the DC-10’s is mounted above the fuselage, and the TriStar was offered only with Rolls-Royce engines.

How do you pronounce L-1011?

“L-ten-eleven.” TriStar is the name Lockheed gave the design, and its internal model number was L-093.