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64-733: The F119 is also the basis for the Joint Strike Fighter (JSF) propulsion system, with variants powering both the Boeing X-32 and Lockheed Martin X-35 concept demonstrators. The X-35 won the JSF competition and the production Lockheed Martin F-35 Lightning II is powered by an F119 derivative, the Pratt & Whitney F135 which produces up to 43,000 lbf (191 kN) of thrust. The F119 resulted from

128-531: A turbofan achieves efficiencies by moving unburned air at a lower velocity, and getting the same effect as the Harrier's huge, but supersonically impractical main fan. Like lift engines, this added machinery was dead weight during flight, but the increased lift thrust enhanced take-off payload by even more. The cool fan also reduced the harmful effects of hot, high-velocity air which could harm runway pavement or an aircraft carrier deck. Though risky and complicated, it

192-685: A complement to the F-22 Raptor . The Joint Advanced Strike Technology (JAST) program was created in 1993, implementing one of the recommendations of a United States Department of Defense (DoD) "Bottom-Up Review to include the United States Navy in the Common Strike Fighter program." The review also led the Pentagon to continue the F-22 Raptor and F/A-18E/F Super Hornet programs, cancel

256-538: A design life of 8,650 total accumulated cycles, with inspection and overhaul of the hot section approximately every 2,000 hours and the cold section every 4,000 hours. While the production F119 on the F-22 incorporates rectangular thrust vectoring nozzles, prototype variants on other aircraft had different nozzle solutions that are tailored to the airframe. The YF119 on the YF-23 had a single-expansion ramp nozzle (SERN) consisting of

320-578: A design similar in size to the Air Force F-35A, trading fuel volume for vertical flight systems. Like the Harrier, guns will be carried in a pod. Vertical flight is by far the riskiest, and in the end, a decisive factor in design. Lastly, the F-35C, a carrier -based (CV) variant, will replace the "legacy" F/A-18 Hornets and serve as a stealthy complement to the F/A-18E/F Super Hornet . It will have

384-399: A larger, folding wing and larger control surfaces for improved low-speed control, and stronger landing gear for the stresses of carrier landings. The larger wing area provides increased range and payload, achieving much the same goal as the much heavier Super Hornet. The U.S. Navy initially planned to purchase 480 JSF; this number was eventually revised to 260 aircraft, with an additional 80 for

448-417: A number of differences between the X-35 and F-35, which was designed to be an operational weapon system. The forward fuselage was lengthened by 5 inches (13 cm) to make room for mission avionics, while the horizontal stabilizers were correspondingly moved 2 inches (5.1 cm) aft to retain balance and control. The diverterless supersonic inlet cowl shape changed from a four-sided to a three-sided shape and

512-560: A result of these media reports, then Australian defence minister Joel Fitzgibbon requested a formal briefing from the Australian Department of Defence on the simulation. This briefing stated that the reports of the simulation were inaccurate and that it did not compare the F-35's performance against that of other aircraft. Andrew Hoehn, Director of RAND Project Air Force, made the following statement: "Recently, articles have appeared in

576-486: A variable wedge flap on the top and a fixed ramp on the bottom, which then transitions to a trench on top of the aft fuselage. While the SERN lacked thrust vectoring capability, it allowed the exhaust to be further cooled in the trenches, significantly reducing infrared signature when viewed from below the aircraft; the trenches in the aft deck were lined with tiles that were " transpiration cooled " from engine bleed air to withstand

640-640: Is a development and acquisition program intended to replace a wide range of existing fighter , strike , and ground attack aircraft for the United States, the United Kingdom, Italy, Canada, Australia, the Netherlands, Denmark, Norway, and formerly Turkey. After a competition between the Boeing X-32 and the Lockheed Martin X-35 , the latter aircraft was selected for a contract award and developed into

704-487: Is the sole 'Level 1' partner, contributing slightly over US$ 2 billion, about 10% of the development costs. Level 2 partners are Italy , which is contributing US$ 1 billion, and the Netherlands , US$ 800 million. At Level 3 are Canada , US$ 440 million; Turkey , US$ 175 million; Australia , US$ 144 million; Norway , US$ 122 million; and Denmark , US$ 110 million. The levels generally reflect

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768-661: The F-16 Agile Falcon in the late 1980s, essentially an enlarged F-16, and continued to mull other designs. In 1992, the Marine Corps and Air Force agreed to jointly develop the Common Affordable Lightweight Fighter, which continued development efforts under ASTOVL. CALF project was chosen after Paul Bevilaqua persuaded the Air Force that his team's concept (if stripped of its lift system ) had potential as

832-705: The F-35 Lightning II , which will replace various tactical aircraft, including the US F-16 , A-10 , F/A-18A-D , AV-8B , EA-6B and British Harrier GR7, GR9s and Tornado GR4 . The projected average annual cost of the program is $ 12.5 billion in 2012 with an estimated cost in 2024 of $ 2 trillion over its lifespan. The JSF program was the result of the merger of the Common Affordable Lightweight Fighter (CALF) and Joint Advanced Strike Technology (JAST) projects. The merged project continued under

896-436: The F-35 Lightning II . The Joint Strike Fighter (JSF) evolved out of several requirements for a common fighter to replace existing types, including the Common Affordable Lightweight Fighter (CALF) program, one of the JSF's predecessors. The actual JSF development contract was signed on 16 November 1996. The JSF program was created to replace various aircraft while keeping development, production, and operating costs down. This

960-804: The Future Carrier Borne Aircraft project. This program sought a replacement for the Sea Harrier (and later the Harrier GR7 ); the Joint Strike Fighter was selected in January 2001. During concept definition, two Lockheed Martin airplanes were flight-tested: the X-35A (which was later converted into the X-35B), and the larger-winged X-35C. Arguably the most persuasive demonstration of the X-35's capability

1024-578: The GAU-22 . The F-35B is the short-takeoff and vertical-landing (STOVL) variant due to replace the U.S. Marine Corps AV-8 Harrier IIs and F/A-18 Hornets , and Royal Air Force / Royal Navy Harrier GR7/GR9s beginning in 2015. The Royal Navy will use this to replace its Harrier GR7s and the RAF replace its Harrier GR9s. The U.S. Marine Corps will use the F-35B to replace both its AV-8B Harrier IIs and F/A-18 Hornets with

1088-574: The JAS 39 Gripen , the F-35 will be the first modern combat aircraft in which helmet-mounted displays will replace a head-up display altogether. During concept definition, two demonstrator airframes for each contractor team would be flight-tested. Lockheed Martin's demonstrator aircraft consisted of the X-35A (which was later converted into the X-35B), and the larger-winged X-35C. Both the X-32 and X-35 power plants were derived from Pratt & Whitney's F119 , with

1152-428: The data into China's Chengdu J-20 and Shenyang FC-31 fighters. On February 1, 2010, Secretary of Defense Robert M. Gates announced that, due to delays and other problems with the JSF development program, he was removing Major General David R. Heinz from command of the program and would withhold $ 614 million in bonuses from Lockheed Martin. On February 16, 2010, Deputy Defense Secretary Bill Lynn announced that

1216-692: The 30,000 lbf (133 kN) class for an aircraft gross weight of 50,000 lb (22,700 kg). Pratt & Whitney and General Electric were selected to make prototype engines, designated YF119 and YF120 respectively, for demonstration and validation (Dem/Val). Both engine makers would provide engines for both the Lockheed/Boeing/General Dynamics YF-22 and the Northrop/McDonnell Douglas YF-23 ATF technology and flight demonstrators. The ATF's increasing weight during development required more thrust to meet

1280-508: The ATF's demanding requirements for supercruise, the PW5000 design has low bypass ratio, high core and turbine inlet temperatures, and a fully variable convergent-divergent nozzle to achieve high specific thrust in intermediate, or non-afterburning power. The combustor, internally named Floatwall, eliminated welds to mitigate crack growth due to thermal cycling. The original RFP called for maximum thrust in

1344-618: The Advanced Turbine Engine Gas Generator (ATEGG) and the Joint Technology Demonstration Engine (JTDE) programs, allowed the design to do more work with fewer stages, with the PW5000's compressor having only 6 stages compared to the 10 stages in the F100 's compressor. The high pressure and low pressure turbines were single stage and counter-rotating, which reduced the gyroscopic forces on the engine; it

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1408-500: The Air Force's Multi-Role Fighter (MRF) and the Navy's Advanced Attack/Fighter (A/F-X) programs, and curtail F-16 and F/A-18C/D procurement. The JAST program office was established on 27 January 1994 to develop aircraft , weapons , and sensor technology with the aim of replacing several disparate US and UK aircraft with a single family of aircraft; the majority of those produced would replace F-16s. Merrill McPeak , former Chief of Staff of

1472-605: The Australian press with assertions regarding a war game in which analysts from the RAND Corporation were involved. Those reports are not accurate. RAND did not present any analysis at the war game relating to the performance of the F-35 Joint Strike Fighter, nor did the game attempt detailed adjudication of air-to-air combat. Neither the game nor the assessments by RAND in support of the game undertook any comparison of

1536-842: The Concept Demonstration phase with an investment of US$ 10 million. This investment allowed Canada to participate in the extensive and rigorous competitive process where Boeing and Lockheed Martin developed and competed their prototype aircraft. Studies supporting JAST/JSF started in 1993 and led to STOVL submissions to the DOD by McDonnell Douglas , Northrop , Lockheed and Boeing : Two contracts to develop prototypes were awarded on November 16, 1996, one each to Lockheed Martin and Boeing . Each firm would produce two aircraft to demonstrate conventional takeoff and landing (CTOL), carrier takeoff and landing (CV version), and short takeoff and vertical landing ( STOVL ). McDonnell Douglas ' bid

1600-711: The Conservatives declared that the total cost over 20 years would be $ 16 billion. On 19 October 2015 the Liberal Party of Canada under Justin Trudeau won a majority in part on a campaign promise to not purchase the F-35, but instead "one of the many, lower-priced options that better match Canada's defence needs". Concerns about the F-35's performance have resulted partially from reports of simulations by RAND Corporation in which three regiments of Chinese Sukhoi Su-27 fighters defeat six F-22s by denying tanker refueling. As

1664-772: The F119 Heavy Maintenance Center (HMC) at Tinker Air Force Base, Oklahoma in the first F119 depot overhaul. Turbine engine advances from ATEGG and JTDE continued with the Integrated High Performance Turbine Engine Technology (IHPTET) program, with applications in F119 improvement packages and derivatives. Prototype YF119 variants powered the Boeing X-32 and Lockheed Martin X-35 Joint Strike Fighter (JSF) concept demonstrator aircraft, and subsequent full scale development of

1728-566: The F119 derivative resulted in the F135 family of engines that powers the Lockheed Martin F-35 Lightning II . The F119 is a twin-spool axial-flow low-bypass turbofan. It has a three-stage fan driven by a single-stage low pressure turbine and six-stage high pressure compressor driven by single-stage high pressure turbine. The shroud-less fan has wide-chord, low aspect ratio hollow titanium fan blades that are linear-friction welded to

1792-492: The F119-PW-100 in order to achieve high specific thrust . The F119 has dual-redundant full authority digital engine control ( FADEC ), also referred to internally as Digital Electronic Engine Control (DEEC), supplied by Hamilton Standard and fully integrated into the F-22's vehicle management system, making the engine highly reliable, stall-resistant, and forgiving of rapid throttle inputs. The three-zone (reduced from four from

1856-529: The General Electric's variable cycle YF120, Pratt & Whitney accrued far greater test hours and emphasized reliability and the lower risk. Ground tests of the F119-PW-100 were first conducted in February 1993. The production engines were fitted on the production F-22 , and were first flown on the F-22's maiden flight on 7 September 1997. A total of 507 engines were produced. In 2013 Pratt & Whitney assisted

1920-668: The JAST name until the engineering, manufacturing and development (EMD) phase, during which the project became the Joint Strike Fighter. The CALF was a DARPA program to develop a STOVL strike fighter (SSF), originally under the Advanced Short Takeoff and Vertical Landing (ASTOVL) project, for the United States Marine Corps and replacement for the F-16 Fighting Falcon . The United States Air Force passed over

1984-494: The JSF program has led to a more conservative and open-ended Future Vertical Lift program. Lockheed Martin X-35 The Lockheed Martin X-35 is a concept demonstrator aircraft (CDA) developed by Lockheed Martin for the Joint Strike Fighter program . The X-35 was declared the winner over the competing Boeing X-32 and a developed, armed version went on to enter production in the early 21st century as

Pratt & Whitney F119 - Misplaced Pages Continue

2048-587: The Joint Advanced Fighter Engine (JAFE) program in the early 1980s aimed at supplying the powerplant for the Air Force's Advanced Tactical Fighter (ATF). Detailed design of Pratt & Whitney's submission, designated internally as PW5000, began when the request for proposals (RFP) for JAFE, later renamed the ATF Engine (ATFE) program, was released in May 1983. Advances in engine technology, such as those from

2112-614: The STOVL variant of the latter incorporating a Rolls-Royce Lift Fan module. Because these were proof of concept demonstrators for STOVL risk reduction, the demonstrator aircraft did not need to have the internal structure or most subsystems of the final aircraft as a weapon system. Instead of lift engines or using a direct lift engine like the Rolls-Royce Pegasus in the Harrier jump jet , the X-35B

2176-485: The U.S. Marine Corps. The primary customers and financial backers are the United States and the United Kingdom. Eight other nations are also funding the aircraft's development. Total program development costs, less procurement, are estimated at over US$ 40 billion, of which the bulk has been underwritten by the United States. Production costs are estimated at US$ 102 million per unit for 2,400 units. There are three levels of international participation. The United Kingdom

2240-558: The UK Minister of Defence Procurement, said the X-35 consistently outperformed the X-32, although both met or exceeded requirements. The development of the JSF was jointly funded by the United States , United Kingdom , Italy , the Netherlands , Canada , Turkey , Australia , Norway and Denmark . In July 2019 United States removed Turkey from the Joint Strike Fighter program, following

2304-523: The US would buy a total of 2,443 JSFs. In April 2009, the Wall Street Journal reported that computer spies, allegedly Chinese but acknowledged to be from uncertain sources, had penetrated the database and acquired terabytes of secret information about the fighter, possibly compromising its future effectiveness. The state-run Aviation Industry Corporation of China (AVIC) has been alleged to incorporate

2368-574: The United States Air Force, has complained that Defense Secretary Les Aspin 's decision to force all three services to use a single airframe greatly increased the costs and difficulty of the project. In November 1995, the United Kingdom signed a memorandum of understanding to become a formal partner, and agreed to pay $ 200 million, or 10% of the concept demonstration phase. In 1997, Canada 's Department of National Defence signed on to

2432-801: The X-35 design were pioneered by the F-22 Raptor , and portions of the VTOL exhaust duct design were previously used by the Convair Model 200 , a 1972 supersonic VTOL fighter requirement for the Sea Control Ship ; in particular, the three-bearing swivel nozzle used in the X-35B was pioneered by the Convair design. Additionally, Lockheed purchased technical data from the canceled Yakovlev Yak-141 in 1991 for examination and analysis of its swivel nozzle. Although helmet-mounted display systems have already been integrated into some fourth-generation fighters such as

2496-462: The X-35's STOVL capability, the X-35B took off in less than 500 feet (150 m), went supersonic, and landed vertically. The X-35C first flew on 16 December 2000 and tested simulated carrier recovery and power approach. In the fly-off between the X-32 and the X-35, the latter was judged to be the winner. As a result, a contract for System Development and Demonstration (SDD) of the F-35 was awarded on 26 October 2001 to Lockheed Martin. There are

2560-420: The clean burning of the fuel and reduced NOx generation. Within the turbine exhaust case, the high-pressure turbine blades are made of single-crystal superalloys and impingement cooled using air from the high-pressure compressor. The high and low pressure spools are counter-rotating. The requirement for the ATF to supercruise, or fly supersonic without afterburners, results in a very low bypass ratio of 0.30 for

2624-470: The country's acquisition of the Russian S-400 missile system . Turkey had planned to buy 100 F-35 Lightning II jets. Lockheed Martin 's X-35 would become the basis of the F-35 Lightning II , currently in production and service; Pratt & Whitney 's YF119-PW-611 would be the basis for the F135 -PW-600 on the production F-35B. On April 6, 2009, US Secretary of Defense Robert Gates announced that

Pratt & Whitney F119 - Misplaced Pages Continue

2688-406: The disks to form single-piece integrally-bladed rotors (IBRs), or blisks. The fan and compressor stators and thrust-vectoring nozzle use a burn-resistant titanium alloy called Alloy C, with the first row of vanes variable in order to increase stall and surge margin. The Floatwall annular combustor is lined with high-cobalt material for oxidation resistance and combustion chamber durability, and ensures

2752-418: The engine core as in a conventional turbofan). Bypass air from the cruise engine medium-bypass turbofan compressor stages exhausted through a pair of roll-post nozzles in the wings on either side of the fuselage, while the thrust from the lift fan balanced the thrust of the hot core stream exhausting through vectored cruise nozzle at the tail. The X-35B powerplant effectively acted as a flow multiplier, much as

2816-495: The exhaust plume and facilitating its mixing with ambient air through shed vortices. The F119 places a high emphasis on human systems integration ; features that facilitate engine maintenance and servicing include modular design such as an axially split case, color-coded cables and harnesses, and a reduction of the number of hand tools required for servicing to just five. Most components are one-deep and servicing can be conducted while wearing hazmat protective clothing. The engine has

2880-477: The fighting qualities of particular fighter aircraft." Furthermore, Maj. Richard Koch, chief of USAF Air Combat Command's advanced air dominance branch is reported to have said that "I wake up in a cold sweat at the thought of the F-35 going in with only two air-dominance weapons" with an Aviation Week article casting an extremely skeptical eye over the (USAF) source of claims that the F-35 would be "400% more effective" than projected opponents. The experience of

2944-409: The financial stake in the program, the amount of technology transfer and subcontracts open for bid by national companies, and the priority order in which countries can obtain production aircraft. Israel and Singapore have also joined as Security Cooperative Participants. Due to delays in development and testing, the introduction date of the F-35 was gradually pushed from 2010 to 2015. Elements of

3008-504: The heat of the exhaust. The specialized YF119 variants on the X-32 and X-35 had provisions for short takeoff and vertical landing (STOVL) operations. The YF119-PW-614 on the X-32 had a pitch-axis thrust vectoring nozzle and valves can redirect the engine exhaust and bleed air to provide direct lift, similar to the Pegasus engine on the Harrier . In contrast, YF119-PW-611 on the X-35 had a round axisymmetric nozzle that can swivel downwards while

3072-578: The low-pressure spool drives a lift fan that's engaged through a clutch; engine bypass air is also routed to roll posts for additional lift and stability. The X-35 won the JSF competition and its shaft-driven lift fan system, called LiftSystem , was fully developed by Rolls-Royce and Pratt & Whitney for the F135-PW-600. Data from Pratt & Whitney, RAND, Aviation Week, USAF. Related development Comparable engines Related lists Joint Strike Fighter Joint Strike Fighter ( JSF )

3136-522: The method of achieving STOVL flight, with the Department of Defense judging that the higher performance lift fan system was worth the extra risk. When near to the ground, the Boeing X-32 suffered from the problem of hot air from the exhaust circulating back to the main engine, which caused the thrust to weaken and the engine to overheat. The United States Department of Defense officials and William Bach ,

3200-488: The performance requirements; as gross weight grew to 60,000 lb (27,200 kg), the required maximum thrust was increased by 20% to 35,000 lbf (156 kN) class. Pratt & Whitney's design changed to incorporate a 15% larger fan, increasing bypass ratio from 0.25 to 0.30. However, unlike General Electric, Pratt & Whitney did not fit its larger fan on flightworthy YF119s for the ATF flight demonstrators to avoid potential reliability issues that may arise. Instead,

3264-474: The pitch axis, greatly improving the aircraft's pitch authority by augmenting the pitching moment of the tail with engine thrust; this enables the F-22 to remain controllable while flying at a trimmed alpha of over 60°. The thrust vectoring is fully integrated into the F-22's flight control system to facilitate handling. The rectangular nozzle's divergent section consists two wedge-shaped flaps for stealth and also contribute to lower infrared signature by flattening

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3328-459: The program will be delayed one year. According to some estimates, overruns could increase the program's total costs to $ 388 billion, a 50% increase from the initial price tag. Many of the program's financial and technical complications result from the Marine version of the JSF, capable of vertical take-offs and landings. On 11 March 2010, United States Senate Committee on Armed Services investigated

3392-524: The progress of the JSF program in a meeting with Pentagon officials, emphasizing cost due to the risk of a Nunn-McCurdy process. According to the Government Accountability Office , F-35A cost has risen from $ 50m in 2002, via $ 69m in 2007 to $ 74m in 2010, all measured in 2002 dollars. Canada reviewed their commitment to the project in December 2012, due to the cost overruns. The decision

3456-477: The prototype) afterburner, or augmentor, contributes to the stealth of the aircraft by having fuel injectors integrated into thick curved vanes coated with ceramic radar-absorbent materials (RAM). These vanes replace the traditional fuel spray bars and flame holders and block line-of-sight of the turbines. The rectangular convergent-divergent nozzle is fully variable for both the convergent throat and divergent areas for high nozzle pressure ratio and can vector ±20° in

3520-410: The revised fan was extensively ground tested at Wright-Patterson Air Force Base. As a result, both the YF-22 and YF-23 had lower performance with the YF119s than with the YF120s. On 3 August 1991, Pratt & Whitney was awarded the EMD contract for ATF engine, while the Lockheed/Boeing/General Dynamics team won the contract for the ATF airframe. While the YF119 was a more conventional design compared to

3584-500: The turbine stage). A portion of engine power was extracted via a turbine, and used to drive a shaft running forward via a clutch-and-bevel gearbox to a vertically mounted, contra-rotating lift fan. This was located forward of the main engine in the center of the aircraft (this can also be viewed the same as a high-bypass turbofan but with the low-pressure fan stages mounted remotely from the engine core on an extended, clutched shaft, and creating thrust downwards rather than back around

3648-404: Was hoped that counter-rotation would eliminate a row of turbine stators for a vaneless high and low pressure turbine interface, which would save weight and reduce parts count, but this was ultimately not successful and the stators were retained. The fan and compressor stages were to use integrally bladed rotors (IBR), also known as blisks, to reduce weight and cost and improve performance. Owing to

3712-493: Was made following a report by auditing firm KPMG that showed that Canada's purchase would cost C$ 45bn over 42 years. Rona Ambrose , Canada's public works minister said: “We have hit the reset button and are taking the time to do a complete assessment of all available aircraft.” Defence Minister Peter MacKay announced Canada's plan to buy the F-35 in 2010 saying that the purchase price was $ 9 billion, but did not provide operating cost estimates. During an election campaign in 2011,

3776-424: Was made to work to the satisfaction of DoD officials, and flight testing of the X-35 demonstrators reduced risk to Technology Readiness Level 6. The X-35A first flew on 24 October 2000 and tested air vehicle performance and handling characteristics. After 28 test flights, the aircraft was converted to the X-35B, which added the shaft-drive lift fan, aft swivel nozzle, and roll posts. On 20 July 2001, to demonstrate

3840-400: Was moved 30 inches (76 cm) aft. To accommodate weapons bays, the fuselage section was fuller with the top surface raised by 1 inch (2.5 cm) along the centerline. Following the designation of the X-35 prototypes, the three variants were designated F-35A (CTOL), F-35B (STOVL), and F-35C (CV). The X-35A was converted into the X-35B for the STOVL part of the competition. It now resides at

3904-433: Was powered by the F119-PW-611 which used the new shaft-driven lift fan system, patented by Lockheed Martin engineer Paul Bevilaqua , and developed by Rolls-Royce. In normal wing-borne flight, the F119-PW-611 was configured as a normal medium-bypass reheated turbofan. The turbofan acted somewhat like a turboshaft engine embedded into the fuselage (but with a much smaller percentage of total heat energy being extracted by

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3968-410: Was pursued by building three variants of one aircraft, with the initial goal of the variants sharing over 70% of their parts. The first is the F-35A, a conventional takeoff and landing (CTOL) variant. It is the smallest and lightest version, and is intended primarily to replace the U.S. Air Force's aging F-16 Fighting Falcons and A-10 Thunderbolt IIs . This is the only version with an internal gun,

4032-419: Was rejected in part due to the complexity of its design. Lockheed Martin and Boeing were each given $ 750 million to develop their concept demonstrators and the definition of the Preferred Weapon System Concept (PWSC). The aim of this funding limit was to prevent one or both contractors from bankrupting themselves in an effort to win such an important contract. Also in 1996, the UK Ministry of Defence launched

4096-444: Was the final qualifying Joint Strike Fighter flight trials, in which the X-35B STOVL aircraft took off in less than 500 feet (150 m), went supersonic, and landed vertically – a feat that Boeing 's entry was unable to achieve. The contract for System Development and Demonstration (SDD) was awarded on 26 October 2001 to Lockheed Martin, whose X-35 beat the Boeing X-32 . One of the main reasons for this choice appears to have been

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