Lockheed L-1011-500 Tristar

The latest serial modification is the L-1011-500 with a fuselage shortened by 4.11 m and an extended wing. The aircraft is equipped with the same RB211-524B4 / -B4I engines as the Tristar -200. Initially, it had a maximum take-off mass of 225 tons. In 1979, it was certified with a mass of 228.6 tons and all previous aircraft of the -500 series were brought to this level. In the future, it became possible to increase to 231.3 tons and most of the L-1011-500 was finalized by reinforcing individual zones of the fuselage, wing, tail unit, and landing gear.

The standard fuel supply is 119774 liters. The flight range with 246 passengers and luggage is 9630 km. Thus, the Tristar-500 has the longest flight range, compared with other serial modifications, due to improved local aerodynamics and an increase in fuel supply and is in competition with the DC-10-30 aircraft. The maximum passenger capacity is 330 people, but not a single aircraft is operated in this version. The largest number of seats – 288 installed on the aircraft of the German airline LTU. A typical layout is to accommodate 250 people in a cabin of two classes. The American Delta uses 233 passengers on long-distance routes. Due to the shortened fuselage, the number of doors is reduced to six. The dimensions of the rear doors have been increased. The kitchens were moved to the upper deck, which allowed them to expand the front cargo compartment.

The aircraft differs from previous modifications in several technical innovations. It has an initial wing of increased scope to increase fuel economy while maintaining the original power structure. To reduce wind and maneuvering loads arising in this case, the wing is equipped with an active control system (ACS). It symmetrically tilts up the external ailerons to redistribute the lifting force to reduce the root bending moment, which gives additional fuel savings and increases the durability of the structure. “Tristar” – 500 became the first equipped with ACS.

Other aerodynamic improvements are new gaps in the junction of the wing with the fuselage, which differ from the original ones in improved geometry, shorter length, and weight. This helps to reduce drag. The use of the so-called Frisbee fairing under the tail engine air intake with a sharp leading edge, which reduces the braking of the airflow in this area and provides a smoother flow around, reduced the noise in the tail section of the passenger cabin and drag. The shells of the air intakes of the wing nacelles have been improved, in particular.

An important improvement of the L-1011-500 is its equipping with the FMS flight optimization system, which was first used on the L-1011-200. The FMS system provides more accurate flight speed control to minimize fuel consumption than is possible with conventional “manual” systems for this purpose. Other aircraft-mounted equipment is a digital autopilot, a digital computer for airborne data systems, an FCS-240 digital automatic flight control system, an automatic take-off thrust control system, and a braking machine. Like earlier models, the new version has a controlled stabilizer, a direct lift control system (automatically deflected spoilers for accurate tracking of the landing glide path), and an automatic landing system in the conditions of the ICAO category IIIA meteorological minimum.

The L-1011-500 program was launched in December 1977 by order of British Airways for six aircraft. L-1011-500 first flew in October 1978. British Airways was the first to commission the aircraft in May 1979 on the London – Abu Dhabi line. Aircraft equipped with the FCS-240 system, which later became standard equipment, was first delivered in mid-1981 to Pan Am and Air Canada airlines. L-1011-500 made a non-stop delivery flight from Palmdale to Amman on October 22, 1981. He covered a distance of approximately 13,200 km in 14 hours 5 minutes, which was a record for cars of this type. This aircraft was one of five L-1011-500 ordered by Jordanian airline Alia. Built 50 L-1011-500. We investigated the L-1011-500VLR (ultra-long) with an additional fuel reserve in the wing of increased scope, several projects of cargo, and passenger-and-freight Tristars.

Cargo L-1011-500F was distinguished by the absence of windows and an additional front side cargo door. The maximum take-off mass remained, as in the original passenger liner. The maximum payload increased to 66.4 tons with a range of 1710 km. The aircraft could carry cargo weighing 58.2 tons at a distance of 6105 km. L-1011-500НВ and -500QC (combined and quick-convertible options) were supposed to have a convertible rear lower cabin and a cargo door behind the wing. The cargo and passenger HB (hatchback) was designed for 138 passengers and four cargo containers. However, neither these nor other projects remained unrealized, and in December 1981, Lockheed announced its intention to stop the production of Tristars. In August 1983, the construction of the last passenger L-1011-500, which took off in October, was completed. The car was handed over to the Government of Algeria to transport dignitaries. A total of 250 aircraft were built, including a prototype. Five of them remained unsold.

Tristar received fewer orders (249) than its competitor DC-10 (446, including 60 KS-10 refueling aircraft), which is mainly due to the financial crisis of Lockheed and Rolls-Royce early 1970s and, as a consequence, a delay in the program. Lockheed was also unable to promptly offer customers a long-range version of the aircraft that could compete with the DC-10-30. The long-range version of the Tristar, but with fewer seats, the L-1011-500 entered service in 1979.

In March 1983, the British Air Force purchased six L-1011-500 from British Airways for conversion into refueling aircraft. Re-equipment was carried out by Marshall Aerospace. Instead of the lower cargo compartments, fuel tanks were installed, as a result of which the maximum fuel supply increased to 136 tons.

In 1990, Marshall Aerospace concluded a contract with Delta for additional fuel tanks for its six L-1011-500 operating on trans-Pacific routes. An additional tank with a capacity of 7040 liters is installed in the front lower cargo compartment instead of two luggage containers, which required some refinement of the airframe. Tanks are installed in September and removed in May for the summer season. With additional tanks, the aircraft is capable of non-stop flights from Portland to Seoul in the winter, when strong headwinds are possible. Without additional tanks, aircraft sometimes have to refuel in Alaska. Tanks are intended for installation only on aircraft with a shortened fuselage

Modification L-1011-500 was mass-produced in 1979-1983. A total of 50 aircraft were built.

Specifications

  • Modification: L-1011-500
  • Wingspan, m: 50.06
  • The length of the aircraft, m: 50.05
  • The height of the aircraft, m: 16.87
  • Wing Area, m2: 329.00
  • Weight kg: empty aircraft 108900; maximum take-off 231500
  • Fuel, l: 119570
  • Engine type: 3 turbofan engine Rolls-Royce RB211-524B4
  • Thrust, kgs: 3 x 22700
  • Cruising speed, km / h: 973
  • Practical range, km: 9700
  • Range with maximum load, km: 6850
  • Practical ceiling, m: 12800
  • Crew: 3-4
  • Payload: 246 passengers in a cabin of two classes or 330 passengers maximum or 44,400 kg of cargo.
Graduated from Embry-Riddle Aviation University with a master's degree in aviation science. He began his career as an aviation researcher in local periodicals. Has a pilot license. Now are the author and developer of the Plane Worlds.