L-1011 History

History

Introduction

Without doubt, Lockheed has been better known for their extensive line of military products. However, their relationship with civil airliners goes back to 1927, when the single-engined six-seat Vega was introduced. This was soon followed by the Sirius, Altair, and Orion. The twin-engined Electra was the fastest airliner at the time of introduction in 1934. The glorious four-engined Constellation was given birth in 1943. In 1966, Lockheed started working on what would become their first commercial jetliner; the L-1011 TriStar. It became the second widebody jetliner to be launched, and though financial difficulties dogged production, the TriStar went on to gain an excellent reputation in service for its reliability, economical efficiency, and especially technology, with Lockheed having had rich experience with a number of military projects. The L-1011 was considered the world's most technologically-advanced airliner at the time of introduction. Not only was the aircraft itself well advanced, but also the process of building the aircraft, adopting a number of new methods and techniques never used before. However, despite these tremendous efforts, the L-1011 program was what led to Lockheed's decision of withdrawing from the civil aircraft business.

Birth of a Trijet

In 1966, more than four years before the venerable Boeing 747 inaugurated service, many airlines were already showing interest in a smaller, medium-range widebody jetliner. The initial specifications were set by American Airlines, who required the new aircraft to be a large capacity, short-to-medium range twin-engined jetliner capable of taking off from smaller airports, with New York's La Guardia being mentioned specifically. The initial design had seating for 250, a maximum gross weight of 300,000 pounds (136,000 kg), and a range of 1,850 nautical miles (2,990 km) with two 50,000-pound-thrust (223 kN) turbofan engines. However, Lockheed was eager to establish a more broader basis for its overall design. Eastern Airlines favored a trijet configuration, as much of their longest routes were overwater, and it was still an era before ETOPS (Extended Twin-engined OPerationS). Trans World Airlines also favored a trijet as they intended the new aircraft to fly U.S.Midwest-to-West Coast segments where the Rocky Mountains were a concern. After discussions with several airlines went on, most of them started to favor a three-engined configuration, although adding a requirement of having a transcontinental range for greater flexibility. The refined design had seating for 330, a maximum gross weight of 400,000 pounds (181.600 kg), and the capability to fly across the U.S. coast-to-coast with three 42,000-pound-thrust (187 kN) engines. By September 1967, Lockheed had come close to finalizing the design, and started to offer the new aircraft with the designation L-1011-365. The "365" corresponded with the planned maximum gross takeoff weight of 365,000 pounds (165,700 kg). It had a capacity of 227 with a gross weight of 320,000 pounds (145,300 kg), and had three engines that were to produce 35,000 pounds of thrust (156 kN). The decision of three engines meant a high level of automatic operations, with fewer restrictions on takeoffs and landings in poor visibility conditions, and enhanced safety in the event of an engine failure. While Lockheed came to settle with the L-1011, McDonnell Douglas were also finalizing their designs on what would become the DC-10.

DC-10 and L-1011

Appearances of the L-1011 and the DC-10 became very much alike, as they were built to meet the same requirements: a 300-seat airliner with a Mach 0.8 cruise and operations from a 9,000 ft (2,700 m) runway on a hot day. However, the most difficult specification to meet was no doubt the capability to operate within the restrictions of La Guardia. Performance parameters were strongly influenced by the airport's geometric and dimensional restraints as well as runway length and a limited maximum gross weight of 270,000 pounds (122,600 kg), although this limit has since been extended. However, though these two are similar, they are not at all identical. When distinguishing the two, the most noticeable difference is the position of the aft engine, or otherwise called the No.2 engine. McDonnell Douglas opted for a straight-duct configuration with the engine mounted on the tail in order to optimize engine performance. On the other hand, Lockheed allocated the third engine in the rear fuselage with the air intake on top of the fuselage. This arrangement is commonly known as the S-duct. This is more similar to that of the Boeing 727 than the DC-10. A series of experiments showed efficiency loss of the engine to be negligible and also showed significant gains in directional stability and maintainability of the engine. In addition, the aft fuselage placement resulted in an improved aerodynamic aft-fuselage configuration, which in turn allowed the fuselage to have a wider aft cabin layout, meaning better comfort for the passenger.

Launching the L-1011

By the beginning of 1968, both Lockheed and McDonnell Douglas had their designs refined, in anticipation of large orders from major U.S. airlines. Lockheed's L-1011 was refined and became the L-1011-385 with a 175 ft (53 m)-long fuselage enabling seating for 250, and a capability of operating economically from La Guardia's 7,000 ft (2,100 m) runway to Chicago with three 37,000-pound-thrust (165 kN) engines. Although these specifications were perfectly ideal for American's operations, the Dallas-based airline announced its selection of the DC-10 on February 19, 1968. Lockheed, shocked by the announcement which put the DC-10 ahead of the L-1011, concentrated on the capability to fly transcontinental range to meet the requirements of other carriers, including Eastern and TWA. By March, the L-1011, by now named "TriStar" in accordance to the manufacturer's tradition of naming aircraft after heavenly bodies, had grown to a maximum gross takeoff weight of 409,000 pounds (185,700 kg), giving a payload of 56,200 pounds (25,500 kg) or 345 passengers. Thrust had grown to 40,000 pounds (178 kN) allowing Mach 0.8 cruising speed at 35,000 ft (10,700 m) over a range of 3,300 miles (5,300 km). In an effort to attract orders, Lockheed agreed to sell under favorable terms if Eastern and TWA selected the L-1011. Finally, on the evening of March 28, TWA came to an agreement with Lockheed, and it was only few hours later when Eastern followed suit. On the morning of March 29, letters of intent for a total of 144 commitments valued at US$2.16 billion were signed and the L-1011 program officially came to a launch. The order included 25 firm and 25 options worth US$860 million from Eastern, 33 firm and 11 options worth US$750 million from TWA, and up to 50 worth US$550 million from British firm Air Holdings Company, which was established to sell or lease the L-1011s to non-U.S. carriers. This value was increased to US$720 million when it was revealed that the order was to be comprised of 30 firm and 20 options. Few days later on April 2, Delta Air Lines added 24 aircraft to the orderbook and Northeast Airlines placed four firm and four options just six days later. These orders were valued at US$360 million and US$50 million respectively. Within a month of the launch date, the L-1011 had attracted a total of 176 commitments worth US$2.74 billion. By this time, the position of Lockheed was reversed with McDonnell Douglas, as they still only had 25 firm and 25 options from American, and that was insufficient for the officials at Long Beach to give a go-ahead with the DC-10. It was not launched until April 26 when United Airlines placed 30 firm and 30 options.

Design

The initial version of the L-1011 would seat up to 270 passengers in a three-class configuration while it would seat up to 300 in an all-economy layout. The aircraft had full transcontinental capability in a mixed-class layout, and could fly between La Guardia to Chicago on a hot day with maximum capacity. Rolls-Royce was selected as the sole source for TriStar powerplants, with Lockheed's engineers feeling that the British engine manufacturer had custom-made the powerplant to the L-1011 and was committed to future power growth of the engine, after initially evaluating the Pratt & Whitney JT9D and General Electric CF6 engine as well. The new RB211 large-fan engines gave high power with low fuel consumption and low noise level. Initial production version of the TriStar had an overall length of 177 ft 8 in (54.2 m), a height of 55 ft 4 in (18.88 in), and a wingspan of 155 ft 4 in (47.35 m). Six passenger doors were planned, two forward and one just behind the wing on each side, plus a set of aft emergency exits. The fuselage design provided a generous 19-ft-7-in cross section to allow comfortable 8-abreast seating in economy and a luxurious 6-cross first class arrangement. Like the DC-10, the L-1011 featured a underfloor galley for preparing in-flight meals and cart storage during takeoff and landing. The L-1011 was set with a range of 3,160 miles (5,100 km) with a payload of 56,200 pounds (25, 500 kg) at an economical cruise speed of 565 mph (910 kph) or Mach 0.85 at an altitude of 31,000 - 35,000 ft (9,500 - 10,700 m). At a gross weight of 409,000 pounds (186,000 kg) it would takeoff and clear an altitude of 35 ft (10.5 m) in a distance of 8,750 ft (2,670 m).

Features

However, the advanced technology incorporated in the TriStar was what put the aircraft ahead of others. Design for improved operational performance and safety led to incorporating three major technology features in the flight control system: full-power controls supported by four independent hydraulic systems; a "flying stabilizer" to eliminate the dangers of miss-trim during takeoff and allow continuous pitch control throughout the entire speed range; and direct lift control to provide a rapid response in maintaining a required approach path for landing. The avionics flight control system, the autopilot, the flight controls, and the cockpit displays were all developed with safe and precise all-weather automatic landing as a prime consideration. The L-1011 became the first aircraft to be certificated automatic landing for all-weather landing conditions during the initial airplane certification program. However, not only was the aircraft's systems advanced, but also the process of manufacture. In such a large new aircraft, it was necessary to keep the weight growth down while retaining structural integrity. New fabrication techniques were adopted, the side walls being semi-monocoque shells with tapered frames and thicker skins, reducing the need for stringers. Not only did this significantly reduce weight but also cut down manufacturing time. With the overall design goal being a lightweight structure but with essentially unlimited fatigue life, Lockheed committed to the advanced metal-to-metal bonding technique. This eliminated 200,000 rivets and fasteners on the airframe, meaning 200,000 fewer holes to crack or corrode, thus providing not only weight savings but also significant advantages for long fatigue life and fail-safe capability. The bonded panels used for the fuselage sides, tops, and floors ranged up to 38 ft (11.4 m) long and 15 ft (4.5 m) wide. Lockheed's giant pressure oven, called the "autoclave", was the largest ever built, with a 22-ft diameter and 66-ft length. As a result of this technique, the L-1011 became the most corrosion-resistant aircraft in the world at the time. Another interesting feature is the painting of the aircraft, which took place in the third largest building of the complex. It was done before moving onto the final assembly line, aiming to produce a higher quality finish in a carefully controlled environment. It would only take 40 minutes to apply 52 gallons (220 liters) of polyurethane paint. After going through the line, the final process of painting was closely monitored, as too much paint could cause a loss of payload while too little provided insufficient protection against corrosion. (More details at L-1011 Features.)

More Customers

With Air Holdings given the responsibility for all overseas sales of the L-1011, Lockheed had the U.S. market all to itself. Overseas sales were expected to reach 175 by 1975 and it was predicted that 500 would be sold overall by 1980. While Northeast converted two options in mid-1968, it was not until December 1968 that Air Holdings made its first sale to Air Canada for 10 firm and nine options. Additional orders were placed in December by Air Finance for three examples and Haas Turner for two aircraft, respectively. Air Jamaica placed an order for two aircraft directly with Lockheed valued at US$30 million, but this was eventually taken out of the Air Holdings allocation. Countering fast-paced sales, Northeast's order for six firm and two options were canceled altogether when the airline started to hold talks to merge with Northwest, which had already placed a substantial number of DC-10s. However, it turned out in a merger with Delta on April 1, 1972. On September 1, 1970, they day when the L-1011 prototype was rolled out, Pacific Southwest Airlines (PSA) signed a letter of intent for two and delivery positions for a further three examples. These were to be placed on the airline's busy 284-mile (526 km) Los Angeles - San Francisco route, anticipating further growth over the next five to six years. All Nippon Airways (ANA) placed an option for six examples in March 1971.

Prototype

Manufacture of the first L-1011 (msn 1001) commenced on March 1, 1969, although the actual assembly did not start until June 24. Interestingly, the first aircraft was built as the new factory was constructed around it. Work on the first fuselage was completed in April 1970, and the cockpit and forward fuselage section was joined with the center section in a gigantic docking jig. The rear cabin up to the pressure dome was added next, followed by the mating of the wings. In June, the first trio of RB211 engines arrived from Rolls-Royce and were installed. Finally, the tail end was attached and the remainder of the parts and equipment were fitted. On July 20, the prototype was structurally completed. September 1 came the rollout of the L-1011, where California Governor Ronald Reagan was invited. Lockheed California Company President Chuck Wagner presented a model of the TriStar to the governor. Following the official rollout, it was towed to the adjacent hangar for functional testing, engine runs, taxi tests, and installation of special instruments that would record data on test flights. On November 16, two and a half year after the launch date, the TriStar lifted off from Palmdale on its maiden flight with the appropriate registration N1011. Flight station crew consisted of L-1011 Project test pilot Hank B. Dees, co-pilot Ralph C. Cokely, flight engineer Glenn E. Fisher, and Flight Test Engineering Team leader Rod C. Bray. Takeoff weight was 330,000 pounds (151,000 kg), which included 85,000 pounds (38,600 kg) of fuel and 40,000 pounds (18,000 kg) of test instruments, including the water ballasts that simulate passenger and baggage load situations by changing the center of gravity. Takeoff run was only 3,500 ft (1,600 m), with a lift off speed of 152 kts (282 kph). During the 2-hr-30-min flight a speed of 250 kts (463 kph) was achieved, and an altitude of 20,000 ft (6,100 m) was reached. Handling characteristics were better than predicted on the ground-based engineering simulator and the engines operated well. Ground observers, including the media, were impressed with the low noise level. This was just a beginning of a flight development involving six aircraft flying 1,700 hours in some 1,500 flights.

msn 1000

In parallel with the production for flight development and customer deliveries, a fatigue test airframe (msn 1000) was built by December 1970. This was basically a complete airframe, with wings, stabilizers, flight control surfaces, the upper structural portion of the nose and main landing gear, pylons that held the wing-mounted dummy engines, and the structure for the aft engine. What was not included was the flight station, which was tested separately. The main purpose of this aircraft was to ensure that any structural problem would be found and corrected long before a similar problem could occur on an aircraft in service. The second purpose was to develop inspection and maintenance techniques and schedules to be used on aircraft in operation. A total of 1,696,000 load cycles simulating 84,000 flights were applied to the airframe. While the first 52,000 flights included all loadings, the last 31,500 flights omitted fuselage pressurization but instead had its wing loads increased from 10% to 20% over the basic spectrum. This amounted to an equivalent of 115,000 flights.

Difficulties Encountered

High costs involved not only in launching a new airplane, but a new engine as well, can be extremely challenging, especially when both are new innovations in technology and scales of operation. During development of the L-1011, events occurred that nearly drove both Lockheed and Rolls-Royce out of business. What made things worse was that both were launched at a time of high inflation and a downturn in the world economy. Development of what was to become the RB211 generated design, development, and manufacturing activity, as well as capital investment, on a scale far exceeding those of any previously U.K.-built commercial airliner engines. Plus, the sole user of the RB211 was the L-1011 at the time. What further helped Rolls-Royce sink in the pit of debt were the technical problems encountered during the development of the engine. Airborne testing, that were carried out on a Vickers VC-10 engine testbed, showed that the front carbonfiber fan blades did not have enough structural strength to withstand the critical bird impact test. The blades were susceptible to erosion and had the tendency to brake off. Proven titanium blades were quickly substituted, but added weight as well as cost to the design. This caused severe delays in an already overly optimistic development schedule. Further, to remain in the commercial jet engine market with competition from Pratt & Whitney and General Electric, Rolls-Royce was forced to lower the prices to below an economic level in the hope of gaining profits out of the eventual long-term business. However, the per-unit price of only US$840,000 turned out to be far too low. Despite receiving aids of almost US$50 million from the British Government, February 4 of 1971 came the financial collapse of Rolls-Royce. Anxious to save one of the national symbols, the British Government received full Parliamentary approval to purchase all assets on February 15, and Rolls-Royce was reborn on February 23. However, they announced it would only retain the RB211 engine if Lockheed agreed to a substantial per-unit price hike and delivery postponement. Since the L-1011 was now locked into the specifications of the RB211, and changing to another powerplant would force major design modifications and further delays as well as even higher costs, Lockheed had no other choice than to agree on a new contract with the British Government. However, besides the direct effect of the Rolls-Royce problems on Lockheed, they already had their own difficulties. Predicting that the L-1011 program would cause a drain on financial resources, Lockheed arranged for a US$400 million line of credit in May 1969. However, the L-1011 was built during high inflation, meaning plummeting demand in airline passenger seats, and the unchanged competitive market forced Lockheed to cut its prices to unprofitable figures. Although they were in the black at US$44 million in 1968, growing development costs of the TriStar caused losses of US$32.5 million the following year. These results would not be too serious if the manufacturer had other profitable programs, however, this was not the case. The C-5A Galaxy heavy-lift transport for the U.S. Air Force was being built to a fixed price contract, and it was subject to cost overruns of approximately US$2 billion, because of a reduction in the size of the original contract and structural problems with the wings. In addition, the cancellation of the Cheyenne helicopter program by the U.S. Army cost US$110 million and there were further cost overruns with the Short Range Attack Missile and a number of U.S. Navy contracts. Together with RB211 problems, the manufacturer was forced to layoff 6,500 employees and cut production. Meanwhile, concerned with the fate of the TriStar, Delta placed a surprising order for five DC-10s plus three options as an insurance. In August 1971, President Richard Nixon signed the Emergency Loan Guarantee Act that guaranteed US$250 million in bank loans to Lockheed, considering that 24,000 jobs and US$1.4 billion in investment were involved. Further, the major launch airlines made advanced payments to protect their interests. Representatives from 24 banks, Rolls-Royce, airlines, the Emergency Loan Guarantee board, and Lockheed met on September 14 and signed documents that provided Lockheed with a US$650 million financing package, including the initial US$400 million. Lockheed's decision of relying on Rolls-Royce as its sole engine source turned out to dog the L-1011 program as a result, causing severe delays and losing customer trust, thus forfeiting substantial sales to the Long Beach rival that was by this time well ahead of the TriStar.

Problems with Air Holdings

In September 1971, Air Holdings Company was fully taken over by British and Commonwealth Shipping (B&C), which had previously held 46% of the shares. Therefore, the contract for 50 L-1011s was inherited by B&C. However, due to the financial difficulties caused by underestimated development costs, customers such as ANA did not make any payments with doubts about the future of the program. At the end of October 1971, Lockheed clarified the orderbook situation; 103 firm and 46 options, which had been confirmed by non-refundable deposits made by airlines. However, B&C had assumed the Air Holdings agreement, and under the contract terms they had failed to make payments on the 29 unsold aircraft out of the 50 by the October 1 deadline. If this was missed, Lockheed had the right to waive the contract and retain all the money deposited until July 31, 1977 to help finance production. As each of the 29 aircraft were sold, refunds would be made to B&C, with all outstanding funds being returned by that date. Air Jamaica's order for two were canceled, but as Air Canada made its own progress payments to Lockheed, deposits by the airline were refunded to B&C. Therefore, Lockheed basically had the worldwide TriStar market all to itself with B&C as just a marketing partner. Soon after the agreement was confirmed, Luton-based Court Line became the first inclusive tour operator to purchase the TriStar, placing an order for two firm and three options, respectively. These aircraft were to be leased to the airline by Airlease, who was the actual purchaser of the aircraft. Although PSA reevaluated their letter of intent towards the end of 1971 due to the financial problems at Lockheed, all five were converted to firm orders in September 1972. The first was scheduled for delivery in spring 1974 featuring an underfloor lounge.

Production

Early on in the L-1011 program, the decision was made to construct a new factory that would be capable of handling planned production rates. Although most of the major parts were assembled in Burbank, Lockheed spent over US$50 million in building Plant 10 at Palmdale, California for final assembly. The so-called "Star Factory in the Desert" was an all-new, purpose-designed, 677-acre manufacturing facility. The seven-building complex was designed to incorporate the most advanced concepts in aircraft production and logistical support. The location was also ideal in terms of weather, as the area was basically a dry and much of the assembling work could be carried out outside. On July 20, 1970, the facility was dedicated by Ronald Reagan, the Governor of California. The main building had a floor space of nearly 1.3 million square feet (120,770 sq m) employing some 6,000 people during peak production, and capable of handling up to 39 TriStars in the assembly jigs, final assembly and flight testing at any one time, and at full capacity, a TriStar could have been delivered every two days. One of the major challenges in starting production was securing suppliers and subcontractors of specialist materials and equipment, as all three U.S. West Coast aircraft manufacturers were launching major airliner programs. Contract was first signed with Avco Aerostructures of Nashville, Tennessee for the manufacture of the wings. Passenger and cargo doors were assigned to Kawasaki Heavy Industries of Japan, Northwest Industries of Canada produced the pressure bulkhead and floor structures while Bristol Aerospace, also from Canada, was responsible for the center engine intake duct. Wing flaps were produced by Aeronca and engine support pylons were manufactured by Murdock Engineering, both companies based in the U.S. The building of the undercarriage units were carried out by Menasco, and the wheels, brakes, and tires came from Goodrich while Goodyear built the anti-skid system. Collins Equipment was responsible for the flight control system and Sperry supplied the air data computer. Lockheed built the remaining parts and equipment.

First Deliveries

The first L-1011 delivery was N306EA (msn 1007) to Eastern on April 5th, 1972. Although service was not scheduled to begin until April 30, it entered service on April 26 on a flight from Miami to New York with 123 passengers, substituting for a Douglas DC-8. By October, they had six 226-seat L-1011s in service. TWA's first example was scheduled for delivery at the same time with Eastern, but their first L-1011 was not handed over until May 10, 1972. Due to the increased engine weight of the L-1011 as a result of the switch to titanium blades, Lockheed raised the maximum gross takeoff weight from 409,000 pounds (186,000 kg) to 430,000 pounds (195,000 kg). Engineers then incorporated a number of minor changes that eventually shed 5000 pounds (2250 kg) from the empty weight. However, as the first dozen airframes were already nearing completion at that time, these retained extra weight, and TWA chose to wait for the reduced-weight aircraft. In fact, the second aircraft to roll off the line was to be TWA's first example, but the N31001 registration was eventually granted to msn 1013. The airline inaugurated service on June 25 from St. Louis to Los Angeles carrying a full compartment of 30 first-class passengers, although filling only 10 seats out of 176 in economy class. There was space for another 14 in the underfloor lounge. Takeoff weight was 378,000 pounds (172,000 kg) including 87,000 pounds (39,500 kg) of fuel for the 1,527-mile (2,450 km) flight. The aircraft cruised at Mach 0.87 at 31,000 ft (9,500 m) giving a speed of 598 mph (962 kph / 520 kts) and a flight time 3 hours and 10 minutes. From the lineup on the runway at St. Louis to rollout after landing at Los Angeles, the aircraft was operated under automatic control. This was a remarkable achievement for a new aircraft at the beginning of its operational carrier, and it also demonstrated TWA's faith in the new airplane.

A Healthy Orderbook

Once again confident with the TriStar, Delta confirmed their commitment for 24 airframes. This included 18 firm and six options. The DC-10s they had ordered as an insurance were dealt to United and leased back until a substantial fleet of L-1011s was built up. Meanwhile, both Lockheed and McDonnell Douglas had put their eyes on the Japanese domestic trunk aircraft market. Therefore it was no surprise when on July 23, 1972, Lockheed flew TriStar N305EA (msn 1006) to Osaka Itami while the other manufacturer sent a DC-10 to Tokyo Haneda. Demonstration flights were carried out the following day between the two airports, switching places. After the Asian tour, N305EA then flew to Europe just in time for the annual Farnborough Air Show in September. British European Airways (BEA) had been considered a potential customer, and Lockheed's confidence came to reality on August 7 when the British Government gave approval to BEA's order for six aircraft with options on six extended-range variants that were being planned by Lockheed. However, with the amalgamation of BEA and British Overseas Airways Company (BOAC) imminent, the order was pending British Airways approval. When BEA formally signed the contract on September 26, six more options were added for a total of 12. Having had experience with the Trident, BEA felt that the automatic landing capability of the TriStar would bring significant operational and economical gains. As a result of Lockheed's sales efforts in Japan, All Nippon Airways (ANA) placed an initial order for six aircraft in October for deliveries commencing in November 1973. Not long after, they added options on a further 15 examples. While ANA selected the TriStar, rival Japan Air Lines selected the Long Beach product. In the same month, Dusseldorf-based inclusive charter operator Lufttransport Unternehmen (LTU) signed a letter of intent for a single example, with another on option. These were to be configured in a 330-seat all-economy arrangement for its daily tourist flights to the Mediterranean resorts. Delta added another six options, bringing the total number committed by the airline to 30. Due to the production schedule slip, the first L-1011 for Air Canada was not rolled out at Palmdale until December. It was delivered on January 14 for entry in service on the Toronto - Miami route. Upon delivery, the Canadian carrier announced plans to acquire up to 30 examples of the trijet. The first British-registered L-1011, G-BAAA named "Halcyon Days", was delivered to Court Line Aviation on February 28, 1973. Although these were to supplement the company's existing fleet on BAC 1-11s on charters mostly to the Mediterranean, plans were well underway to deploy the type on services to the Caribbean where Clarksons Holidays held significant hotel and resort interests. The flights were to make a technical stop in the Azores. However, due to financial problems with Clarksons, parent company Shipping Industrial Holdings sold the tour company to Court Line. As 40% of the airline's profits were generated by Clarksons, net income was significantly slashed, and further financial difficulties forced them to consider deferring their third L-1011 and cancel its two options. Meanwhile, their second example, G-BAAB "Halcyon Breeze", arrived at Luton on May 3. The first TriStar for LTU was delivered on May 29, and was followed by the first for Delta on September 7. Service was inaugurated on December 15 mostly on eastern U.S. routes. Delta became the first airline to operate all three widebodies; the 747, DC-10, and L-1011. Meanwhile, ANA had converted eight options in September and another two in October, bringing their firm order to 16. ANA not only intended to place the type on domestic routes but also on charter flights to the Oceania region. In October, BEA had also converted options for three.

Developing a Family

Since the early stages of L-1011 development, Lockheed had envisioned developing a family of airliners so that both the manufacturer and the airlines can benefit from common equipment, thus enabling production to be more efficient and maintenance more economical. Initial developments of the TriStar were mainly concerned with extending the range by increasing the thrust of the RB211 powerplants. Dubbed the L-1011-8.4, the first extended-range concept was revealed in 1969. It was to be powered by three 52,200-pound-thrust (232 kN) RB211-56 engines, which would allow up to 280 passengers to be carried over a distance of 6,000 miles (9,600 km). The increased takeoff weight of 575,000 pounds (261,000 kg) was to be supported by a strengthened undercarriage. Fuselage dimensions would have been increased by 40 in (1.2 m) to 182 ft 8 in (55.7 m) in length and 20% in wing area. However, this idea was shelved when Lockheed encountered severe difficulties. February 1972 saw the comeback of a similar concept, this time designated the L-1011-2. Although this variant would have the same dimensions as the standard aircraft, gross weight would have been increased to 466,000 pounds (212,000 kg) with structural strengthening. This would give a range of 4,000 miles (7,400 km). In August, the British Government gave approval to Rolls-Royce for developing the new RB211-24 engine which would be suitable for the L-1011-2. The RB211-24 engine was later renamed the RB211-524 engine, emphasizing the significant refinements over the original engine while retaining maximum commonality. It would have an improved fuel consumption with a thrust of 50,000 pounds (222 kN). Technical refinements included reduced operating temperatures, and increase in mass flow of air through the engine and a slight reduction in the by-pass ratio. Together, these gave the aircraft the capability to cross the Atlantic in all conditions. In April 1973, further details were released, anticipating a launch order. Maximum takeoff weight was increased to 488,000 pounds (222,000 kg) of which 7,000 pounds (3,200 kg) accounted for structural strengthening, giving a range of 4,000 miles (7,400 km) at Mach 0.82 with 273 passengers. At this point, the engines were to develop 45,000 pounds of thrust (200 kN), but it was increased to 48,000 pounds (213 kN) within a month. This allowed either a 70-passenger increase in capacity or a 400-mile (650 km) extension in range. The gross weight was also planned to grow to 516,000 pounds (234,000 kg). However, the oil crisis which started in late-1973 forced the manufacturer to halt development of the L-1011-2 in the short measure. Meanwhile, they concentrated on modifying existing TriStars by adding an extra fuel tank between the wing spars in the center section, increasing the maximum takeoff weight to 466,000 pounds (212,000 kg). A L-1011-3 with the fuselage length increased by 20 - 40 ft (5 -12 m) was also considered, but this came to be a short-lived concept.

Oil Crisis Hits the World

The oil crisis of the that hit the world economy in late 1973 had heavy impact on both Lockheed and the airlines. Overcapacity forced Eastern to defer orders for nine TriStars, which led to the expense of the manufacturer to slow down the production line. However, the situation improved when Delta, TWA, and soon ANA took advantage of the overcapacity and requested earlier deliveries. In March 1973, Hong Kong-based Cathay Pacific Airways signed a letter of intent for two L-extended-range variants and options for more examples. These carried a larger center fuel tank, bringing the takeoff weight up to 460,000 pounds (209,000 kg). In the same month, Saudia placed an order for two L-1011-100s with options on three more. The additional range was achieved by adding improvements to the RB211-22 engines and carrying more fuel in the wings, bringing the takeoff weight to 450,000 pounds (204,000 kg). Although the manufacturer was still in the light, dark clouds were starting to gather over the Atlantic when Court Line ceased trading on the London Stock Exchange in June. They had suffered from a reduction by one third of their holiday bookings, severe losses in their tanker and ship-building business, and financial problems in their Caribbean interests. Despite cash deposits by the British Government, the airline went into liquidation on August 15. Its two colorful TriStars were sold back to Lockheed and stored at Palmdale. Countering sad events, it was a time of celebration when Lockheed launched the long-range L-1011-200 on September 19 with an order from Saudia for two examples. This type was powered by uprated RB211-524 engines developing 48,000 pounds of thrust (213 kN) providing a range of 4,700 miles (7,600 km). In the same month, ANA converted four more options to firm orders. Meanwhile, the first L-1011 for British Airways rolled off the production line. Registered G-BBAE, it was delivered to the flag carrier on October 21 seating 20 in first class and 300 in economy. Just a month later, the company placed an order for three more standard TriStars, bringing the total number committed to 15. However, service was not inaugurated until January 12 from London to Paris, after a series of route-proving flights were completed. By November, Delta had replaced their DC-10 fleet and converted three options, bringing its total to 21. A month later saw another Middle-East airline, Gulf Air, opting for the TriStar with an order for four L-1011-100s with options on an additional four machines. However, the recession continued in 1975, leading to a number of carrier with surplus equipment. Both Eastern and TWA had excess capacity of TriStars, and PSA was forced to ground its entire TriStar fleet until June. The two major U.S. operators began to offer its L-1011s on the secondhand market, and LTU immediately took advantage of a single example from Eastern. The first L-1011-100 for Saudia was accepted by the airline in July, and was placed into service on August 15. After struggling to attract orders, it finally received its first order for over a year from Delta in January 1976 for one aircraft. However, the availability of secondhand TriStars led to the cancellation of two options by Cathay Pacific, which acquired a handful of L-1011s from Eastern. TWA offered delivery positions for sale, and Saudia took advantage of two. In April 1976, Lockheed had 157 firm orders and 50 options on the orderbook of which 127 had been delivered. They were forced to cut the production rate and slow down development of newer versions. Although the rival DC-10 also struggled to collect sales, they sold more overall, and the new Airbus was making significant sales progress with the A300 twin-widebody. The situation became even worse when PSA grounded their L-1011 fleet again, leaving the manufacturer with three undelivered airframes in addition to the two returned by defunct Court Line. Eastern intended to dispose additional examples and TWA was selling off planes directly off the production line. However, a sign of a slow recovery finally peeked out from the clouds when Saudia placed an order for three more L-1011-200s.

Climbing Out of the Pit

By the end of 1976, passengers were slowly coming back to the air. Delta confirmed two options in August for delivery in May and December 1978, respectively. In October, LTU reached an agreement with the manufacturer to exchange its two TriStars for three former PSA examples that had been stored since the company's demise. All of these were configured with the underfloor lounge, enabling a high-capacity arrangement of 330. In February 1977, Delta confirmed another option, leaving with five options and bringing the total firm orders to 25. Satisfied with the trijet since entry into service, Air Canada was eager to place the L-1011 on services across the Atlantic as soon as its financial figures improved. Instead of ordering new extended-range variants, they took advantage of Lockheed's offer to upgrade original models to L-1011-100 standards, thus saving significant costs. The center fuel tank was capable of carrying 19,000 pounds (8,600 kg) of fuel, increasing the takeoff weight by 36,000 pounds (16,300 kg) to 466,000 pounds (212,000 kg). This boosted the range by 900 miles (1,700 km) to 3,700 miles (6,800 km) with a load of 257 passengers, giving full transatlantic capability. Service was inaugurated as early as April 1977 from Montreal and Toronto to major European cities. TWA also opted for the conversion program and initially took advantage of four. April saw ANA confirming three more options, bringing their total to 20, followed by Saudia which purchased two more L-1011-200s the following month for a total of 10. They received their first L-1011-200 on May 27. In August, Delta added another two to the orderbook. About a year later in October 1978, Lockheed was able to sign yet another deal with Delta. They confirmed its remaining five options and placed an order for 15 more options, which extended deliveries until 1984. January 1979 saw selection of the L-1011-200 by British Airways for two examples. Gulf Air followed suit in August and also agreed to acquire two. Just a month later, the British flag carrier added six more options, bringing the total number of TriStars committed by the airline to 23. Delta continued to add more L-1011s, and confirmed two options in March 1980. A few months later, three more options were converted and another three were also confirmed the following year. By mid-1983, Delta planned to have 44 TriStars in service.

Dash 500: Technological Refinement

Lockheed was anxious to produce a true long-range model, as the range capability of the L-1011-200 still could not match that of the DC-10-30. Substantial sales were forfeited to the Long Beach manufacturer due to the inability to provide full intercontinental range. At the end of 1974, Lockheed had announced the development of the L-1011-250. This had a 18,000-pound (8,200 kg) increase in gross takeoff weight over the L-1011-200 to a total of 484,000 pounds (220,000 kg), providing a range of 3,500 miles (5,600 km). The additional weight was to be accomplished by installing a larger fuel tank and strengthening its structure. However, a refined long-range concept was announced in November 1975 in response to a BEA requirement for a long-range version of the L-1011. Designated the L-1011-500, it combined the 50,000-pound-thrust (222 kN) engines and the strengthened structure that was planned for the L-1011-250. Fuselage length was reduced in length by 20 ft 2 in (6.1 m), with 15 ft removed from the forebody just ahead of the wing and 5 ft 2 in (1.6 m) from the afterbody just behind the trailing edge. Fuel capacity was increased by 22,000 pounds (10,000 kg) with the addition of extra center fuel tanks, allowing the range to be extended to 5,400 miles (10,000 km) accommodating up to 231 passengers. This allowed the Dash 500 to fly virtually all intercontinental routes of the time. Maximum takeoff weight was increased to 490,000 pounds (222,500 kg). Although it could have been ready for entry into service by 1977, overcapacity caused by the economy downturn delayed the launch. At the end of 1977, Rolls-Royce delivered the first 50,000-pound-thrust (222 kN) RB211-524B engines to Lockheed for testing on Saudia's first L-1011-200, and this was expected to grow to 53,000 pounds (235 kN) for the Dash 500. Certification of the new engine was obtained in March 1976. By this time, the dimensions of the L-1011-500 were modified and in the following month, Lockheed announced a newly refined Dash 500 to customers. This time, removal in the forebody was reduced to 8 ft 4 in (2.5 m) although the 5-ft-2-in (1.6 m) removal in the afterbody was unchanged to allow seating for 246 in a 10%-first-class, 90%-economy arrangement. The maximum takeoff weight had been increased to 496,000 pounds (225,000 kg) of which 400 pounds (182 kg) accounted for structural strengthening. 54,000 pounds (24,500 kg) of extra fuel was carried in the center tank to allow a range of 5,300 miles (8,500 km). This led to the underfloor galley being relocated to the maindeck. By this time, the L-1011-250 concept was abandoned. The structural materials and arrangements on the Dash 500 were basically identical to those of the standard model. According to the results of the initial fatigue test program, maximum fatigue cutoff stress levels were equally applicable with the design of the L-1011-500. Structural joints were also the same, although additional stringers were added to reduce cabin noise. The Dash 500 was designed for long-range operations, but its structural fatigue life in numbers of flights was identical to that of the L-1011-1. Structural fatigue life in commercial airliners is mainly concerned with the number of flights flown instead of flight hours. Since the structural fatigue lives of the Dash 500 and the standard version are equal, therefore the long-range variant would have a longer fatigue life than that of the L-1011-1 based on numbers of flights flown, considering that the number of hours per flight for the Dash 500 would be twice as long as that of the L-1011-1. Range capability was well enhanced, but the design refinements also deserve a note for their technological significance. A strengthened wing was deployed to cope with the higher gross weight and was structurally reinforced for active ailerons (Active Controls System). The wingspan was increased by 9 ft (2.7 m) to comply with the deployment of active ailerons and to give a 2.5% fuel saving. The No 1 and 3 engine pylons were reinforced to cope with the increased-thrust engines and reduced fuselage length. The pylons were also re-contoured to reduce drag. The wing fuselage fairing was shortened and lightened to reduce drag and to accommodate the shorter fuselage. A diverter fairing named the "Frisbee Fairing" was installed to the inlet duct for the No 2, or otherwise called the aft engine. A significant noise reduction in the aft cabin was accomplished by changing the inlet flow, as well as drag reduction. This was subsequently offered as an option on all models. A new Flight Management System (FMS) was developed to control the aircraft precisely, thus leading to significant fuel savings. It held the speed to within one knot (1.15 mph / 1.85 kph) of the selected figure and the aircraft would rise and sink through 100 ft (30 m) height band. The new system was also offered on standard-length TriStars and the first example to receive the treatment was a L-1011-200 for Gulf Air. (More details at L-1011 Features.)

A Dream Finally Launched

It was August 1976 when Lockheed was finally able to pop some bottles of wine with the launch of the L-1011-500. British Airways converted six of its options for earlier models to the Dash 500 and further added six options. BEA and BOAC had formally merged on April 1, 1974. They were to place the new aircraft on thin transatlantic routes from London with 18 first-class and 217 economy class seats. Lockheed particularly aimed at the customers that were shopping to replace their fleets of first-generation jetliners such as the Boeing 707 and Douglas DC-8, and predicted that L-1011-500 sales could reach 244. Not surprisingly, Delta placed an order for two aircraft in January 1978 with options on another three. Anxious to place the long-range TriStar on their newly-granted Atlanta - London Gatwick route, they leased a pair of L-1011-100s from TWA and temporarily converted them to L-1011-200 standards and placed them on the route at reduced payload until their Dash 500s arrived. A significant order came from Pan American World Airways (Pan Am) in April for 12 aircraft with options on another 14 to replace their Boeing 707s on routes to South America. It is said that the contract came later than expected, as Pan Am had been pressing the manufacturer to produce a Pratt & Whitney-powered variant of the Dash 500 to have commonality with their Boeing 747 fleet. In September, British West Indies Airways (BWIA) received government approval to order two examples and two options. Soon the two options were confirmed. The first L-1011-500, the 157th TriStar, rolled out at Palmdale on October 12. Unlike the original TriStar development program, they were running a month ahead of the planned flight testing timetable and the maiden flight took place only four days after rollout, on October 16. Flight testing involved the first and second aircraft, covering over 530 flight hours. Meanwhile, the orderbook steadily continued to grow and Delta confirmed a single option in March 1979. The following month saw Air Canada placing an order for six aircraft with nine options as part of a 10-year fleet renewal program. The first aircraft for launch customer British Airways was the third Dash 500 and was delivered to the airline on April 30 for service entry into service in May on routes to the Middle East and southeast Asia. September that year saw TAP Air Portugal sign a letter of intent for three machines with options on another two. However, the Portuguese Government did not give approval until the airline proved an economical case for the new aircraft after years of severe losses. In the same month, Delta took delivery of their first example. Pan Am's first Dash 500 first took to the skies on November 16, beginning a 330-hour flight testing program involving also their second aircraft to gain FAA certification with particular reference to the extended wingtips and active controls. At the end of the year, Royal Jordanian Airlines (Alia) placed an order for five to replace their aging Boeing 707s. In January 1980, BWIA took delivery of their first aircraft and placed it into service on their flights to Europe from the Caribbean. Three months later, LTU received its first Dash 500. Configured in an all-economy 276-seat configuration, it was placed into service on charter flights across the Atlantic. In March, Air Lanka agreed to acquire two examples with options on another two to replace their Boeing 707s. On April 1, the Dash 500 tailor-made for Pan Am achieved FAA certification and entered service by the end of the month. October that year saw the TAP order finally approval by the government, 13 months after the signing the letter of intent. The two options were later confirmed for a total of five. At the end of 1980, Lockheed completed the first retrofitting of a British Airways' example with more fuel-efficient RB211-524B2 engines. In April 1981, the first example for Air Canada was delivered and was placed into service on routes to Europe with seating for 244. Five months later, Royal Jordanian accepted their first example and Air Lanka received their first in August 1982.

End of the Line

Following the confirmation of the TAP contract, sales prospects from new customers diminished. A significant number of TriStars were available on the secondhand market and the evolution of new high-technology widebody twinjets, the Boeing 767 and Airbus A310, made sales of the TriStar further unlikely. In fact, Air Canada canceled its nine options with their commitment to the new Boeing jetliner while Air Lanka subsequently canceled its two options and instead acquired two TriStars from ANA. The first-quarter loss in 1981 was US$36 million, an increase over the same period in the previous year. Aero Peru had placed options for a few aircraft, but these were never confirmed. Air India signed a letter of intent to acquire up to eight L-1011-500s with deliveries to commence in early-1983, but these too were never taken up. Only three aircraft were sold that year, and Lockheed became concerned about running the assembly line at a substantially slower pace. After evaluation showed that Lockheed would be significantly more profitable by terminating the TriStar program even including cancellation costs, they announced that they would take no further orders and planned to cease production in 1984. At the time of the fateful announcement, 21 firm orders and 40 options were outstanding. Lockheed needed to sell 24 aircraft per year between 1985 and 1990 to make the L-1011 program viable, but depression in the commercial airliner market that was not expected to improve until at least 1986 made these levels extremely hard to sustain. Although they decided to close the line down, the manufacturer guaranteed to build any converted options providing they were confirmed by mid-1982. The final five TriStars, all Dash 500s, were built on speculation and were placed in storage at Palmdale upon rollout. Four were later dealt to Royal Jordanian while the ultimate machine was purchased by the Algerian Government. 250 airframes were eventually produced, including the prototype, which never entered service with an airline. 161 were L-1011-1s, 15 were L-1011-100s, 24 were L-1011-200s and 50 were L-1011-500s. Total losses of the L-1011 program amounted to nearly US$2.5 billion, of which US$400 million accounted for tax written off by shutting down the line.

TriStars Just on the Drawing Board

Lockheed's goal was always to develop a family of airliners. The L-1011-100, L-1011-200 and the Dash 500 are fortunate designs that were able to take to the air, but there are also significant concepts that took shape. In autumn 1976, the manufacturer announced the L-1011-300 with 410 passengers on the maindeck and a further 45 in the underfloor cabin. This would have added 15 ft (4.5 m) each to the forebody and afterbody of the airframe, giving an overall length of 207 ft 4 in (63.2 m). Max takeoff weight was estimated to be 466,000 pounds (211,000 kg). This high-capacity design was aimed especially at an ANA requirement for a high-capacity domestic airliner. However, the cancellation of the development was obvious when ANA selected the Boeing 747SR (Short Range). By the mid-1970s, Lockheed started developing a short-to-medium range version where the fuselage of the Dash 500 would be powered by the de-rated RB211-22 engines. In early 1977, the idea came in the shape of the L-1011-400. This would have had a takeoff weight of between 350,500 and 374,500 pounds (159,000 - 170,000 kg) with carrying 200 to 250 passengers over a distance of 2,700 miles (5,000 km). The manufacturer planned to add significant refinements to the new variant that would further reduce noise levels, improve fuel consumption, and reduce maintenance costs. The L-1011-600 BiStar was basically a twin-engined L-1011-500. Carrying between 174 and 200 passengers, it would have had a range of 2,000 to 2,700 miles (3,700 - 5,000 km) at a maximum takeoff weight of 297,000 pounds (135,000 kg). No customers showed interest in these models. By the end of 1980, Lockheed's developments focused on variants based on the Dash 500. The L-1011-500 Stretch would have combined the fuselage of the L-1011-200 and the active controls and wings of the Dash 500 to allow transatlantic capability. A Dash 500 for 'hot and high' operations was also conceived. This would have been powered by uprated RB211-524D4 engines developing 53,000 pounds of thrust (235 kN). The manufacturer also considered building the ailerons and fins with composite material to save weight. However, all developments were terminated when Lockheed ceased production of the TriStar.

Continuing Support

Although all developments ceased, Lockheed continued to offer modest improvements in the fashion of conversion kits that were mainly concerned with reducing maintenance costs, improving fuel economy and extending the range. The manufacturer and Rolls-Royce jointly announced in October 1985 a conversion program that would extend the range from 2,700 miles (5,000 km) to 4,500 miles (8,300 km). This was accomplished by re-engining with uprated high-thrust RB211-524B4 engines and strengthening the structure to Dash 500 standards. Maximum takeoff weight was increased by 15% to 496,000 pounds (225,000 kg) while fuel capacity was increased from 150,600 pounds (68,400 kg) to 214,000 pounds (97,000 kg). This conversion could be completed over a period of five to eight weeks and cost around US$35 million per airframe. The designation L-1011-250 was revived for this variant when it was launched by Delta with an order for six kits. They were the only customer. In 1990, the L-1011-150 conversion was offered to increase the maximum takeoff weight by 18,000 pounds (40,000 kg) to 470,000 pounds (213,000 kg), allowing a modest 700-mile (1,300 km) increase to 3,100 miles (5,800 km). This was taken up by Air Canada, Air Transat and American Trans Air. The L-1011-50 was a conversion which increased the gross weight to 450,000 pounds (204,000 kg) by simply strengthening the undercarriage.

Military Conversions

One of main reasons why the DC-10 remained in production six years longer than the TriStar is that they had the KC-10 Tanker program which built 60 airframes for the U.S. Air Force, while Lockheed enjoyed no such support. At the beginning of the 1980s, the British Government was looking for a long-range high-capacity tanker transport capable of refueling in the air. In September 1982, discussions commenced with the options being either British Caledonian DC-10s or British Airways L-1011s. The former was offered by British Aerospace while the latter was offered by Marshall Aerospace of Cambridge. On February 2, 1983, a contract was signed with Marshall to convert six surplus British Airways Dash 500s. The conversion was not an easy task. It was necessary for a new fuel system to be installed because the government required the tankers to carry 45 tons of fuel in the underfloor cargo bay. A number of other new equipment and systems were deployed, thus leading to structural modifications. Another challenge was the installation of a large forward cargo door, which was a first on a TriStar. The four aircraft were completed in K Mk.1 ('K' for Kerosene) tanker/passenger configuration, lacking the forward cargo door. The first example made its maiden flight on July 9, 1985. The fifth and six airframes were completed in KC Mk.1 ('C' for Cargo) tanker/cargo/passenger configuration. The first and third aircraft later returned to Cambridge for conversion to KC Mk.1 standards. In 1984, three L-1011-500s were purchased from Pan Am, but due to the detail differences, these could not be converted to the same KC Mk.1 configuration. These received minor modifications and basically remained a pure-passenger model, which became known as the C Mk.2. One of the three former Pan Am machines were upgraded to C Mk.2A standard with a slightly higher takeoff weight and differences in autopilot, but it was later converted back to comply with the other two C Mk.2s. In 1997, the Saudi Government considered converting Saudia's entire fleet of 17 L-1011-200s to tankers for the Saudi Air Force, but this plan has since been shelved.

Freighter Conversions

The idea of a TriStar freighter first emerged during the development of the initial L-1011 in the early 1970s. Designated the L-H2, it was an epoch-making airliner, that said it was designed to run on liquid hydrogen. Unfortunately, it never took shape. A more modest freighter variant in the form of the L-1011-500F was conceived in October 1979 for the Flying Tiger Line. Maximum payload of 146,400 pounds (66,500 kg) could be carried as far as 925 miles (1,700 km) but it were to be increased to 3,300 miles (6,100 km) if payload was reduced to 128,400 pounds (58,300 kg). By September 1980, this plan had been shelved. From 1990 onwards, Lockheed's primary interest was in cargo conversions. Hayes International (now Pemco Aeroplex) undertook the freighter conversion of a single L-1011-1 (msn 1012) for use in New Zealand. The process included the deletion of all windows, strengthening the structure, and installing a large cargo door in the forward section on the port-side. However, the aircraft was overweight and did not enter service. The problem arose because the floor beams of the TriStar are more critically loaded than on other airliners that great care has to be taken when strengthening them in order not to add too much weight. The mishandled airliner later received small modifications from Lockheed and successfully entered service with TradeWinds. By 1991, Lockheed received interest from two potential customers that intended to convert their passenger airframes to cargo configuration after retirement from airline service. Saudia also joined the list when they showed interest in converting most, if not all of their L-1011-200 fleet to freighters. With commitments worth going ahead with the project, the manufacturer launched the Lockheed 2000, which was a freighter based on the standard-length TriStars. The manufacturer felt that Marshall's conversion program was difficult to adapt to civil standards. The conversion would have cut out a huge 14 ft 1 in by 9 ft 6 in (4.3 x 2.9 m) forward cargo door for transporting oversized cargo over distances of 2,500 miles (4,600 km) with payloads up to 122,200 pounds (55,400 kg). Takeoff weight was targeted at 466,000 pounds (212,000 kg). Conversion was to be taken out by Lockheed Aircraft Service at Tucson and a contract with Avtec of Switzerland was signed to market the freighters. The first conversion was to be on a L-1011-1 that was acquired from LTU in 1995, but after a lack of interest for the program continued, it was finally canceled in late-1997. Meanwhile across the ocean, Marshall Aerospace was interested in going ahead with its own L-1011 freighter conversion, having had success with the tanker conversions for the Royal Air Force. Marshall selected the L-1011-200 as the ideal model for the conversion, increasing the gross weight from 466,000 pounds (212,000 kg) to 474,000 pounds (215,000 kg). It is designed to carry up to 23 7 ft 4 in by 10 ft 5 in (2.25 x 3.2 m) pallets on the maindeck, 16 LD-3 containers weighing up to 36,000 pounds (16,400 kg) in the forward cargo hold, and another eight weighing up to 18,000 pounds (8,200 kg) in the rear hold. Marshall's facility at Cambridge is capable of handling up to three conversions simultaneously and if additional business is achieved, Lockheed Martin Aircraft and Logistics Centers at Greenville, North Carolina has the capacity to accommodate a further two. The conversion process takes 18 to 22 weeks. American International Airways (Kalitta) launched the program in July 1994 with an order for three conversions and options on a further five. The airline purchased eight former British Airways L-1011-200s for the purpose, and not long after, three options were confirmed. In early 1995, International Air Leases (IAL) placed an order for three conversions for lease to Arrow Air. Gulf Air L-1011-200s were allocated to this contract. In 1996, well-known commercial aircraft lessor International Lease Finance Corporation (ILFC) ordered a single conversion for Millon Air. The aircraft was provided by LTU. However, since then they have received no orders. In 2000, Lockheed Martin planned a revival of their own TriStar freighter conversion program with considerable interest from Intercapital of London to convert 13 retired Delta examples and Custom Air Support to convert up to 16 retired Saudi Arabian (nee Saudia) examples. However, these deals never materialized due to the lack of interest and the plan was shelved again.

Satellite Launcher

In 1993, Marshall Aerospace was responsible for yet another major conversion program that involved modifying a former Air Canada L-1011-100 into a satellite launch platform for the Orbital Sciences Corporation. Modifications to the TriStar included the support and attach structure on the bottom of the fuselage, hydraulic attachment and release mechanism, aerodynamic fairings to accommodate the Pegasus satellite, payload air conditioning system, a nitrogen purge system, umbilicals, launch panel operator station, and a number of equipment for testing and launching of the satellite. The Pegasus has a wing which fits under the fuselage, with an anhedral tailplane, and the fin recessed into the unpressurized hydraulic service center. Christened "Stargazer", the modified TriStar successfully completed its made flight on July 12, 1993. The satellite is launched at an altitude of 38,000 ft (11,600 m) and can carry both the Hybrid Pegasus and the larger Pegasus XL. The RB211 engines are modified to give 10% higher power at the moment of release in order to counter the substantial rearward movement of the center of gravity. In 1999, the "Stargazer" returned to Cambridge for modification to carry the joint NASA/Orbital Sciences X-34. This would have served as a testbed for new technologies requiring a high-speed, high-altitude flight environment. However, with the cancellation of the project by NASA in March 2001, the aircraft was placed under an active storage program at Mojave.

Flying Hospital

In mid-1995, Lockheed was contracted by Pat Robertson's 'Operation Blessing' International Relief and Development to modify a L-1011 into a 'flying hospital'. Former PSA L-1011-50 (msn 1064) had the honor of receiving the 18-month conversion period between 1995 and 1996 at Lockheed's Aeromod Center based in Tucson. The flying hospital has a seating section which accommodates 67 people, mainly for transportation and medical classes. The surgical facility has four operating stations supplemented by pre and postoperative recovery area that is capable of handling 12 patients. A small surgery station, X-ray equipment, flourosacan, autoclave sterilizers, and a laboratory are also aboard the aircraft. Taking advantage of the underfloor lounge, it was refurbished into a pharmacy with a full check-in/check-out reception. A crew rest area is also located on the below deck. Other major modifications include the installation of an on board oxygen generation system, medical grade air and vacuum systems, and a water purification system. There were also significant avionics installed on the aircraft including windshear detection equipment, Global Positioning System satellite navigation, TCAS II collision avoidance system, and SATCOM equipment. The aircraft currently operates under the Flying Hospital Inc, providing medical relief worldwide.

The Legacy Lives On

The TriStar was unable to formally complete its career with Eastern, for they shut their doors on January 18, 1991 after 22 months of operating under Chapter 11 bankruptcy protection. Air Canada retired their standard-length L-1011s at the end of October 1990, although their Dash 500s were retained until early 1992 when Boeing 767-300ERs took over the routes. By the same period, British Airways had also retired its TriStar fleet in favor of Boeing's new twinjet. Gulf Air retired their last L-1011s in February 1995 in favor of Boeing 767-300ERs also, although three examples were briefly recalled from storage in 1997. ANA sold a few TriStars to Boeing in exchange for new 767s in the mid-1980s, but the bulk of its fleet remained until retirement commenced. Their last revenue flight with the L-1011 was on November 25, 1995. Cathay Pacific operated 20 TriStars, of which most were former Eastern examples, but rapid retirement started when deliveries Airbus A330s and A340s progressed and the last revenue flight was on October 15, 1996. TWA was one of a handful of airlines that severely endured after deregulation, and their reduced fleet of TriStars was finally retired on September 3, 1997. Air Lanka, now known as SriLankan Airlines, operated their TriStars until March 2000 when they were finally replaced by Airbus A330-200s. However, airlines such as Delta took advantage of the relatively-early retirements of the TriStars in the early 1990s, and acquired a total of 24 off the secondhand market to become the world's largest operator of the type with no less than 56 TriStars spanning their extensive domestic and international network at peak time. Other enthusiastic secondhand buyers were Air Atlanta Icelandic, which acquired Cathay Pacific and TWA aircraft, Air Transat, which acquired examples from Air Canada and TAP, American Trans Air (ATA), whose fleet consists of mostly Delta and Royal Jordanian examples, Rich International, which acquired ANA examples, and a handful of charter carriers based in Europe. It proved especially popular in Sweden, hence the number of Swedish registered L-1011s. Air Ops, Nordic East, and Novair are noteworthy operators, although the former two went out of business during TriStar operation. Rich was another unfortunate carrier that was forced to cease operations in 1997. Over 30 years have now passed since the first TriStar first took to the skies. Delta finally retired their last L-1011 on July 31, 2001, with the type being replaced by new-generation Boeing 777s and 767-400ERs. Secondhand operators have also started gradual retirements, and airlines such as Air Atlanta, Caledonian and Novair have phased out their fleets recently. However, the increasing number of stored TriStars and the industry's trend toward twin-engined widebodies have significantly made the L-1011 less expensive and more affordable for smaller airlines. Hewa Bora Airways of the Democratic Republic of Congo has recently commenced intercontinental operations with the TriStar while airlines such as Kampuchea Airlines of Cambodia steadily continue to expand its fleet. Meanwhile, operators such as Air Transat and ATA will gradually retire its fleet but phase out is not expected to be completed for three or four more years. The L-1011 was designed with an airframe durable for essentially unlimited fatigue life if properly maintained, and Lockheed Martin will continue to provide all necessary technical support as long as the TriStar is in operation. Approximately only 50 remained in service at March 2002, and though this number will likely continue to shrink, the TriStar deserves the honor of being one of the most trouble-free jetliners ever built and its technology still remains highly appreciated in the industry today.

Editor's Note

This page was last updated on: March 22, 2002