In the 1960s, American Airlines approached Lockheed and competitor Douglas with a need for an aircraft smaller than the existing 747, but still capable of flying to distant locales such as London, the Caribbean, and Latin America from company hubs in Dallas/Ft Worth and New York. The Model L-1011 was designed to enter this category with optimum payload-range performance and short-field characteristics. The Model L-1011 is powered by three 42,000-lb. s.t. turbofan engines, two of which are mounted in pods underneath each wing, and the third is located in the rear of the fuselage at the base of the tail unit. The TriStar’s engine is integrated into the tail through an S-duct for improved quietness and stability. Fuel is carried in two integral wing tanks and an inboard tank. With a full load, the TriStar can travel a maximum of 4,467 miles. Accommodations provide for 256 passengers in a mixed coach and first-class arrangement or a maximum of 400 passengers in a high density all-economy configuration.

Lockheed L-1011 Tristar Article

First flown on November 16, 1970, the twin-aisle TriStar’s design schedule closely followed that of its competitor, the DC-10, Douglas beat Lockheed to market by a year due to delays in powerplant development. Rolls-Royce, the maker of the TriStar’s RB211 turbofan engines, had filed for bankruptcy, halting L-1011 final assembly. The first flight was powered by Rolls Royce RB.211 high by pass ratio turbofan engines, from Palmdale, California.

The British government did not approve the large state subsidy used to restart Rolls-Royce operations until after the U.S. government had guaranteed the Lockheed loans previously provided to Rolls for the extensive engine contract. (The UK Goverment also took the contentious step (for a Conservative administration) of taking the aero-engine side of RR into public ownership, to maintain national defence capability). Its first revenue flight, for Eastern Air Lines, was made on 26 April 1972.

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

Ironically, American Airlines never flew the “Ten Eleven,” purchasing many DC-10s instead.

Lockheed manufactured a total of 250 TriStars, ceasing production in 1984. Lockheed needed to sell 500 planes to break even. Failing to achieve profitability in the civilian airliner sector, the TriStar was to be Lockheed’s last commercial aircraft.

Flying all of its life on test and development work, the prototype was acquired by Aviation Sales of Ardmore in August 1986.

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L-1011 Tristar
Engines: 3 x Rolls Royce RB.211 22B turbofan, 42,000 lb / 180.5kN
Wing span: 155 ft 4 in (47.34 m).
Length: 178 ft 8 in (54.35 m).
Height: 55 ft 4 in (16.87 m).
Wing area: 312.1 sq.m / 3359.41 sq ft
Empty wt. 102000 kg / 222,941 lb
Max TO wt: 430,000 lb (195,045 kg).
Fuel capacity 23,814 USG
Max level speed: M0.9.
Cruise 474 mph.
Stall 144 mph.
Initial climb rate 2,800 fpm
Ceiling: 42,000 ft.
Range w/max.payload: 5000 km / 3107 miles
Pax cap: 345.
Takeoff run 7,590 ft
Landing roll 5,660 ft
Crew: 2-3

To meet a US Air Force requirement for an ‘off-the-shelf’ high-performance light transport, Lockheed developed the Lockheed 1329 JetStar. A low-wing monoplane with swept wings and swept tail surfaces, the JetStar was powered in prototype form by two 2200kg thrust Bristol Orpheus 1/5 turbojet engines. The JetStar flew 241 days after design began, in 1957. The first of two prototypes was flown on 4 September 1957, with flight testing proving satisfactory, but when planned licence-production of the Orpheus engine could not be finalised.

Lockheed L-731 / L-1329 JetStar Article

Lockheed chose to power the initial production version by four 1361kg thrust Pratt & Whitney JT12A-6 engines, mounted in pairs on each side of the rear fuselage. The anticipated military demand failed to materialise in any significant numbers, with the result that the majority of the 204 JetStars that were built, before production ended in 1980, were sold as business/executive aircraft.

As advertised – Dec 2011

AiResearch Aviation Company’s 731 JetStar made its first flight on July 10 1976 from San Antonio, Texas.
The TFE 731 is 10 inches larger in diameter than the JT12A, so the drag produced from the larger nacelles needed to house it would lessen the benefits of its lower fuel consumption. Also, the modified aircraft weighs 1,750 pounds more than its predecessor, so the gross weight would have to be increased in order to retain the same payload, but a high¬er gross weight means more drag. The TFE731 3 turbofan produces only 400 pounds more takeoff thrust than does the JT12A 8 turbojet, so there was not a significant amount of extra power to overcome drag.

Ed Swearin¬gen designed a TFE 731 installation for the JetStar. He also warped both ailerons so that the outer portions are biased slightly upward in neutral position to act as “reverse” flaps, thus forcing the inboard section of the wing to carry a greater share of the lifting loads. By designing a new fuel tank below the wing instead of wrapping it around the airfoil, Swearingen was able to reduce the size of the pod without sacrificing any fuel capacity and eliminate all nacelle flow disturbances caused by the tanks.

Wind tunnel studies showed that despite its larger nacelles, the overall drag of the 731 JetStar would be slightly less than that of the original JT12A powered version.

A supplemental type certificate for retro¬fitting Garrett TFE 731 3s to JetStars was granted to AiResearch on June 10, 1976, nearly two years after the aircraft’s first flight. Flight tests had demonstrated that the turbofan 731 JetStar exceeded the performance of its turbojet predecessor in take¬off, rate of climb, initial cruise altitude and cruise speed at altitude. The 731 JetStar will go 2104 nm with full IFR reserves.

Pro¬duction JetStar IIs differs only slightly as, because the aircraft is newly manufactured, the aft fuselage bulk¬heads can be relocated, rather than modified (as they must be on the 731 JetStar), to ac¬commodate the Garrett engines; thus the na¬celle installation is about 175 pounds lighter than the AiResearch arrangement. The first production example (N5527L) of the Lockheed 1329 25 JetStar II 12 seat executive transport made its first flight at Marietta, Georgia on 18 August 1976.

American Aviation Industries, founded 1985 and offered Lockheed JetStar business jet re-engining program as the FanStar.

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Variants:

JetStar I
Original production version, differing from the first prototype by having increased fuel capacity provided by a permanently attached streamlined JuelI tank at mid-span of each wing, de-icing of wing and tail unit leading edges and Pratt & Whitney JT12A-6 engines; a slightly lengthened fuselage provided executive standard accommodation for a crew of two and 10 passengers; late production aircraft had 1497kg thrust JT12A-8 turbojet engines

JetStar 731
Conversion developed by AirResearch, replacing the Pratt & Whitney powerplants of Jet Star I aircraft with more fuel-efficient Garret TFE731-1 turbofan engines; about 60 JetStar Is were converted to this standard

JetStar II
New production version incorporating Garrett TFE731-3 engines as standard and a number of refinements

C-140A
Five aircraft for USAF, similar to early production JetStar Is and equipped for calibration of navigation beacons

C-140B
Convertible cargo/passenger version for USAF, five built; generally similar to C-140A

VC-140B
Designation of six additional production aircraft, generally similar to C-140A, except equipped as VIP transports; the five C-140Bs were also converted to this configuration

Specifications:

Lockheed JetStar II
Engines: 4 x Garrett TFE731-3 turbofans, 1678kg
Max take-off weight: 20185 kg / 44501 lb
Loaded weight: 11294 kg / 24899 lb
Wingspan: 16.59 m / 54 ft 5 in
Length: 18.41 m / 60 ft 5 in
Height: 6.22 m / 20 ft 5 in
Wing area: 50.4 sq.m / 542.50 sq ft
Max. speed: 880 km/h / 547 mph
Ceiling: 13105 m / 43000 ft
Range: 4820 km / 2995 miles

Lockheed 731 Jetstar-6, -8 Jetstar II (Airesearch conversion)
Engines: 4 x Garrett TFE 731 3, 3,700 lbs
Length: 60 ft. 5 in
Height: 20 ft. 5 in
Wingspan: 54 ft. 5 in
Wing area: 542.5 sq. ft
Airfoil: NACA 63A1 12 at root, NACA 63A309 modified at tip
Aspect ratio: 5.27
Passenger seats: 10
Takeoff weight: 43,750 lbs
Operating weight: 24,178 lbs
Useful load: 19,572 lbs
Payload with full fuel: 1,750 lbs
Zero fuel weight: 27,000 lbs
Fuel capacity: 2,640 USG/17,822 lbs
Wing loading: 80.6 lb/sq.ft
Power loading: 2.96 lbs/ft.sq
Baggage area: 104.9 cu.ft
Cabin pressure differential: 8.9 psi
Cabin altitude @ 43,000 ft: 7,500 ft
Balanced field length: 6,250 ft
Takeoff safety speed: 145 knots
Initial rate of climb: 4,200 fpm
Gross takeoff climb rate, one engine out: 2,400 fpm @ 220 kt
Engine out service ceiling: 37,000 ft
Maximum operating altitude: 43,000 ft
Maximum operating Mach: 0.82 M
Maximum cruise: 475 kt / 0.82 M
Normal cruise: 0.76 M
Long range cruise: 438 kt / 0.72 M
Maximum range, 45 minute reserve 2,770 nm
Range max fuel/cruise: 2331 nm/4.9 hr
Range max fuel / range: 2956 nm/ 6.8 hr
Maneuvering speed (@ 20,000 ft. and 35,000 lb): 220 knots
Stall speed, landing configuration: 108 knots
Stall clean: 138 kt.
1.3 Vso: 140 kt
Vmc: 103 kt

Lockheed was one of at least five US aerospace companies which apparently received contracts in 1973 from the US Defense Advanced Projects Research Agency (DARPA) to study signature reduction techniques and their potential application to a manned combat aircraft. The effort was code-named Have Blue.

Lockheed’s Advanced Development Projects organisation at Burbank (ADP), more commonly known as ‘The Skunk Works’, already had practical experience in the design of stealth aircraft; low radar signature had been a significant consideration in the Blackbird family of Mach 3.0 reconnaissance aircraft. But rivals, such as General Dynamics, McDonnell Douglas and Northrop, were the then current manufacturers of fighter aircraft for the US military. Even to this day it has not been officially confirmed that Lockheed was the only Have Blue contractor to be funded as far as the hardware stage of an Experimental Stealth-Tactical (XST) prototype. It seems unlikely. It is known, however, that funding for this and other stealth projects was accelerated in 1977, and that the Lockheed design was airborne from the secluded and top secret Groom Lake airfield, on the Nevada test range in December 1977, flown by ADP chief test pilot Bill Park. Although only half the size of the F-117A, this aircraft’s configuration was broadly similar, except for the vertical tail surfaces. Apparently these were individually-mounted and inwardly canted, similar to those of the Blackbird series. The prototype Lockheed stealth aircraft was powered by two General Electric J85 turbojets and used an adapted F-16 fly-by-wire system.

Using special-access, fast-track procedures, the programme developed rapidly, despite the crash of a prototype at Groom Lake on 4 May 1978. After a hard landing which damaged the starboard undercarriage member, Bill Park elected to apply power and climb away in order to assess the damage. Following another abortive approach, he was obliged to eject, but sustained serious injuries and never flew the aircraft again. The landing problem was attributed to faulty fly-by-wire software; Ken Dyson took over as the contractor’s chief test pilot. There were at least two other Lockheed prototypes, however, and they were evidently flown with great success against various radars on the Nevada range. Ground test vehicles were sent for radar cross-section measurement on large-scale outdoor ranges, with similarly encouraging results. By the end of 1978, Lockheed had received a USAF contract to develop a full-scale production version. It contained warranties covering the aircraft’s range, weapons delivery accuracy and radar cross section.

Both prototypes ultimately crashed, one in May 1978 and the other in 1980, with their pilot’s ejecting.

The wreckage of the two Have Blue aircraft was buried within the Nellis Test Range. One was reportedly buried at the Groom Lake site just south of the hangar complex. Lockheed engineers have since searched for the buried Have Blue with a view to restoring it for display purposes, but despite their best efforts have been unable to locate the wrecked aircraft.

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XST
Engine: 2 x General Electric J85, 1270kg
Max take-off weight: 5440 kg / 11993 lb
Wingspan: 6.86 m / 22 ft 6 in
Length: 11.58 m / 37 ft 12 in
Height: 2.29 m / 7 ft 6 in
Crew: 1

In 1946 the new Strategic Air Command of the USAAF placed an order for the development of a so-called penetration fighter; a long-range fighter able to fly ahead of the bomber force and sweep aside all fighter opposition. The XF-90 evolved over two years and resulted from 65 different designs created by Johnson’s engineers. These included butterfly-tailed aircraft, three-engine aircraft, ‘W’ winged designs. Lockheed’s Model 153 submission was thought to offer great potential and was ordered in the form of two XF-90 prototypes. The two prototypes were to be tested in a fly-off competition with the McDonnell XF-88 and North American YF-93A designs.

Developed by Clarence L. (Kelly) Johnson’s Lockheed fighter team, the design had a number of similarities to the company’s F-80 Shooting Star, but was of more advanced aerodynamic concept. It had a finely tapered forward fuselage, two laterally mounted 4200-lb (1905-kg) afterburning thrust Westinghouse J34-WE-11 turbojets, and flying surfaces swept at 35 degrees. A radius of about 1100 miles (1770-km) was provided by considerable internal fuel supplemented by jettisonable wingtip tanks. This was calculated to provide an escort capability into the western USSR from bases in West Germany, and a potent offensive punch was provided by a combination of four 20-mm cannon with six 0.5-in (12.7-mm) machine-guns. The final XF-90 had 12.7mm rivets in the wings and weighed as much as a DC-3.

The first aeroplane flew on 4 June 1949 at Muroc, piloted by Tony LeVier. It cruised around 15,000 ft for 37 minutes. The twin Westinghouse J-34 were assisted by a pair of externally mounted JATO rockets for the gross weight of 26,000 lb.

It was immediately revealed to be drastically under-powered with twin 1406kg thrust Westinghouse J34-WE-11 turbojets. The XF-90 reached 1070km/h at 9784m in level flight and could easily be pushed through the sound barrier in a shallow dive. Throughout April and May 1950, above Muroc Dry Lake, Lockheed test pilot Tony LeVier put the XF-90 through high-speed dive tests. LeVier dived the XF-90 to Mach 1.12 on 17 May 1950.

The XF-90 stalled at 204km/h, making it no easy machine to control on the approach. Its take-off performance enabled it to clear a 15m obstacle in 2629m without the rocket-assisted take-off (RATO) units used in some tests. In the 1949 fly-off, the XF-88 came in first, the XF-90 second, and the YF-93A third, but by then the results were academic. With the September 1949 detonation of the Soviet Union’s first nuclear weapon, the USAF’s requirement was changing at this time, so the project was cancelled.

The second XF-90 was rigged with instruments on the ground and destroyed in the 1952 atomic bomb tests at Frenchman’s Flat, Nevada. Lockheed records indicate that the first XF-90 was shipped in 1953 to a National Advisory Committee for Aeronautics (NACA) laboratory in Cleveland, Ohio. Apparently, it was eventually broken up in tests at that NACA facility.

Engines: 2 x Westinghouse J34-WE-11 turbojets, 1406kg thrust
Max take-off weight: 12300 kg / 27117 lb
Empty weight: 8400 kg / 18519 lb
Wingspan: 12.19 m / 39 ft 12 in
Length: 17.12 m / 56 ft 2 in
Height: 4.8 m / 15 ft 9 in
Wing area: 32.05 sq.m / 344.98 sq ft
Max. speed: 1070 km/h / 665 mph
Ceiling: 11800 m / 38700 ft
Range: 3700 km / 2299 miles