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107-768: X51 or X-51 may refer to: Boeing X-51 , a scramjet-waverider from the Air Force Research Laboratory X-51 ( Deus Ex ) , a fictional organization in the video game Deus Ex X-51 (Machine Man) , a fictional character in the Marvel Comics Universe X51 (New York City bus) , express bus route in New York City Axim X51 , PDA made by Dell X51 FAA LID for Homestead General Aviation Airport in Florida [REDACTED] Topics referred to by

214-528: A Harrier jump jet replacement for the U.S. Marine Corps (USMC) and the UK Royal Navy . Under one of ASTOVL's classified programs, the Supersonic STOVL Fighter (SSF), Lockheed Skunk Works conducted research for a stealthy supersonic STOVL fighter intended for both U.S. Air Force (USAF) and USMC; among key STOVL technologies explored was the shaft-driven lift fan (SDLF) system. Lockheed's concept

321-538: A splitter gap or bleed system to divert the boundary layer away from the inlet duct, eliminating the diverter cavity and further reducing radar signature. The RCS of the F-35 has been characterized as lower than a metal golf ball at certain frequencies and angles; in some conditions, the F-35 compares favorably to the F-22 in stealth. For maintainability, the F-35's stealth design took lessons from earlier stealth aircraft such as

428-502: A strafing run. The aircraft is powered by a single Pratt & Whitney F135 low-bypass augmented turbofan with rated thrust of 28,000 lbf (125 kN) at military power and 43,000 lbf (191 kN) with afterburner. Derived from the Pratt & Whitney F119 used by the F-22, the F135 has a larger fan and higher bypass ratio to increase subsonic thrust and fuel efficiency , and unlike

535-473: A 5,000 lb (2,300 kg) inboard station and a 2,500 lb (1,100 kg) middle station, or 1,500 lb (680 kg) for F-35B. The external wing stations can carry large air-to-surface weapons that would not fit inside the weapons bays such as the AGM-158 Joint Air to Surface Standoff Missile (JASSM) or AGM-158C LRASM cruise missile. An air-to-air missile load of eight AIM-120s and two AIM-9s

642-421: A dedicated attack platform, USAF chief of staff Mark Welsh placed a focus on weapons for CAS sorties, including guided rockets , fragmentation rockets that shatter into individual projectiles before impact, and more compact ammunition for higher capacity gun pods. Fragmentary rocket warheads create greater effects than cannon shells as each rocket creates a "thousand-round burst", delivering more projectiles than

749-611: A draft specification in 2011 for an alternative HMDS based on the AN/AVS-9 night vision goggles as backup, with BAE Systems chosen later that year. A cockpit redesign would be needed to adopt an alternative HMDS. Following progress on the baseline helmet, development on the alternative HMDS was halted in October 2013. In 2016, the Gen 3 helmet with improved night vision camera, new liquid crystal displays, automated alignment and software enhancements

856-778: A four-sided to a three-sided cowl shape and was moved 30 inches (76 cm) aft. The fuselage section was fuller, the top surface raised by 1 inch (2.5 cm) along the centerline and the lower surface bulged to accommodate weapons bays. Following the designation of the X-35 prototypes, the three variants were designated F-35A (CTOL), F-35B (STOVL), and F-35C (CV), all with a design service life of 8,000 hours. Prime contractor Lockheed Martin performs overall systems integration and final assembly and checkout (FACO) at Air Force Plant 4 in Fort Worth, Texas , while Northrop Grumman and BAE Systems supply components for mission systems and airframe. Adding

963-522: A less galvanic corrosion -inducing skin gap filler, fewer gaps in the airframe skin needing filler, and better drainage. The flight control system uses electro-hydrostatic actuators rather than traditional hydraulic systems; these controls can be powered by lithium-ion batteries in case of emergency. Commonality between variants led to the USMC's first aircraft maintenance Field Training Detachment, which applied USAF lessons to their F-35 operations. The F-35

1070-632: A missile, reconnaissance, transport, and air-breathing first stage for a space system. Data from Boeing, Air Force Performance Lockheed Martin F-35 Lightning II The Lockheed Martin F-35 Lightning II is an American family of single-seat, single-engine, supersonic stealth strike fighters . A multirole combat aircraft designed for both air superiority and strike missions, it also has electronic warfare and intelligence, surveillance, and reconnaissance capabilities. Lockheed Martin

1177-672: A naval development of USAF's ATF program to replace the F-14 , resulted in additional fighter capability being added to A-X, which was then renamed A/F-X. Amid increased budget pressure, the DoD's Bottom-Up Review (BUR) in September 1993 announced MRF's and A/F-X's cancellations, with applicable experience brought to the emerging JAST program. JAST was not meant to develop a new aircraft, but rather to develop requirements, mature technologies, and demonstrate concepts for advanced strike warfare. As JAST progressed,

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1284-475: A sawtooth pattern at the trailing edge, which reduces radar signature and creates shed vortices that reduce the infrared signature of the exhaust plume. Due to the engine's large dimensions, the U.S. Navy had to modify its underway replenishment system to facilitate at-sea logistics support. The F-35's Integrated Power Package (IPP) performs power and thermal management and integrates environment control, auxiliary power unit, engine starting, and other functions into

1391-666: A single system. The F135-PW-600 variant for the F-35B incorporates the Shaft-Driven Lift Fan (SDLF) to allow STOVL operations. Designed by Lockheed Martin and developed by Rolls-Royce , the SDLF, also known as the Rolls-Royce LiftSystem , consists of the lift fan, drive shaft, two roll posts, and a "three-bearing swivel module" (3BSM). The nozzle features three bearings resembling a short cylinder with nonparallel bases. As

1498-461: A speed of Mach 5 (3,300 mph; 5,300 km/h), an altitude of 70,000 feet (21,000 m) and flew for over 200 seconds; it did not meet the planned 300 second flight duration, however. The test had the longest hypersonic flight time of 140 seconds while under its scramjet power. The X-43 had the previous longest flight burn time of 12 seconds, while setting a new speed record of Mach 9.68. Three more test flights were planned and used

1605-507: A trimmed alpha of 50°. Relaxed stability and triplex-redundant fly-by-wire controls provide excellent handling qualities and departure resistance . Having over double the F-16's internal fuel, the F-35 has a considerably greater combat radius , while stealth also enables a more efficient mission flight profile. The F-35's mission systems are among the most complex aspects of the aircraft. The avionics and sensor fusion are designed to improve

1712-578: A unique subvariant of the F-35A, designated the F-35I, that is designed to better interface with and incorporate Israeli equipment and weapons. The Israeli Air Force also has their own F-35I test aircraft that provides more access to the core avionics to include their own equipment. The United States is the primary customer and financial backer, with planned procurement of 1,763 F-35As for the USAF, 353 F-35Bs and 67 F-35Cs for

1819-436: A wing-tail configuration with two vertical stabilizers canted for stealth. Flight control surfaces include leading-edge flaps , flaperons , rudders , and all-moving horizontal tails ( stabilators ); leading edge root extensions or chines also run forwards to the inlets. The relatively short 35-foot wingspan of the F-35A and F-35B is set by the requirement to fit inside USN amphibious assault ship parking areas and elevators;

1926-529: Is a key piece of the F-35's human-machine interface. Instead of the head-up display mounted atop the dashboard of earlier fighters, the HMDS puts flight and combat information on the helmet visor, allowing the pilot to see it no matter which way they are facing. Infrared and night vision imagery from the Distributed Aperture System can be displayed directly on the HMDS and enables the pilot to "see through"

2033-458: Is considerably heavier than the lightweight fighters it replaces, with the lightest variant having an empty weight of 29,300 lb (13,300 kg); much of the weight can be attributed to the internal weapons bays and the extensive avionics carried. While lacking the kinematic performance of the larger twin-engine F-22, the F-35 is competitive with fourth-generation fighters such as the F-16 and F/A-18, especially when they carry weapons because

2140-493: Is developing a weapon rack called Sidekick that would enable the internal outboard station to carry two AIM-120s, thus increasing the internal air-to-air payload to six missiles, currently offered for Block 4. Block 4 will also have a rearranged hydraulic line and bracket to allow the F-35B to carry four SDBs per internal outboard station; integration of the MBDA Meteor is also planned. The USAF and USN are planning to integrate

2247-478: Is different from Wikidata All article disambiguation pages All disambiguation pages Boeing X-51 Waverider refers in general to aircraft that take advantage of compression lift produced by their own shock waves . The X-51 program was a cooperative effort by the United States Air Force , DARPA , NASA , Boeing , and Pratt & Whitney Rocketdyne . The program was managed by

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2354-644: Is expected to be continually upgraded over its lifetime. The first combat-capable Block 2B configuration, which had basic air-to-air and strike capabilities, was declared ready by the USMC in July 2015. The Block 3F configuration began operational test and evaluation (OT&E) in December 2018 and its completion in late 2023 concluded SDD in March 2024. The F-35 program is also conducting sustainment and upgrade development, with early aircraft from LRIP lot 2 onwards gradually upgraded to

2461-513: Is expected to receive propulsion upgrades over its lifecycle to adapt to emerging threats and enable additional capabilities. In 2016, the Adaptive Engine Transition Program (AETP) was launched to develop and test adaptive cycle engines, with one major potential application being the re-engining of the F-35; in 2018, both GE and P&W were awarded contracts to develop 45,000 lbf (200 kN) thrust class demonstrators, with

2568-524: Is known as "concurrency", some low rate initial production (LRIP) aircraft lots would be delivered in early Block configurations and eventually upgraded to Block 3F once development is complete. After 17,000 flight test hours, the final flight for the SDD phase was completed in April 2018. Like the F-22, the F-35 has been targeted by cyberattacks and technology theft efforts, as well as potential vulnerabilities in

2675-496: Is possible using internal and external weapons stations; a configuration of six 2,000 lb (910 kg) bombs, two AIM-120s and two AIM-9s can also be arranged. The F-35 is armed with a 25 mm GAU-22/A rotary cannon, a lighter four-barrel variant of the GAU-12/U Equalizer . On the F-35A this is mounted internally near the left wing root with 182 rounds carried; the gun is more effective against ground targets than

2782-475: Is the prime F-35 contractor with principal partners Northrop Grumman and BAE Systems . The aircraft has three main variants: the conventional takeoff and landing (CTOL) F-35A, the short take-off and vertical-landing (STOVL) F-35B, and the carrier variant (CV) catapult-assisted take-off but arrested recovery (CATOBAR) F-35C. The aircraft descends from the Lockheed Martin X-35 , which in 2001 beat

2889-467: Is then jettisoned and the vehicle's Pratt & Whitney Rocketdyne SJY61 scramjet accelerates it to a top flight speed near Mach 6 (4,000 mph; 6,400 km/h). The X-51 uses JP-7 fuel for the SJY61 scramjet, carrying 270 lb (120 kg) on board. DARPA once viewed X-51 as a stepping stone to Blackswift , a planned hypersonic demonstrator which was canceled in October 2008. In May 2013,

2996-544: Is tilted backwards for stealth. Complementing the radar is the AAQ-37 DAS, which consists of six infrared sensors that provide all-aspect missile launch warning and target tracking; the DAS acts as a situational awareness infrared search-and-track (SAIRST) and gives the pilot spherical infrared and night-vision imagery on the helmet visor. The ASQ-239 Barracuda electronic warfare system has ten radio frequency antennas embedded into

3103-465: The 20 mm gun carried by other USAF fighters. In 2020, a USAF report noted "unacceptable" accuracy problems with the GAU-22/A on the F-35A. These were due to "misalignments" in the gun's mount, which was also susceptible to cracking. These problems were resolved by 2024. The F-35B and F-35C have no internal gun and instead can use a Terma A/S multi-mission pod (MMP) carrying the GAU-22/A and 220 rounds;

3210-632: The AGM-88G AARGM-ER internally in the F-35A and F-35C. Norway and Australia are funding an adaptation of the Naval Strike Missile (NSM) for the F-35; designated Joint Strike Missile (JSM), two missiles can be carried internally with an additional four externally. Both hypersonic missiles and direct energy weapons such as solid-state laser are currently being considered as future upgrades; in 2024, Lockheed Martin disclosed its proposed Mako hypersonic missile, which can be carried internally in

3317-806: The Boeing X-32 to win the Joint Strike Fighter (JSF) program intended to replace the F-16 , F/A-18 , and the Harrier jump jet , among others. Its development is principally funded by the United States, with additional funding from program partner countries from the North Atlantic Treaty Organization (NATO) and close U.S. allies, including Australia, Canada, Denmark, Italy, the Netherlands, Norway,

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3424-776: The F-22 Advanced Tactical Fighter (ATF) program. The A/F-X, initially known as the Advanced-Attack (A-X), began in 1991 as the USN's follow-on to the Advanced Tactical Aircraft (ATA) program for an A-6 replacement; the ATA's resulting A-12 Avenger II had been canceled due to technical problems and cost overruns in 1991. In the same year, the termination of the Naval Advanced Tactical Fighter (NATF),

3531-912: The GBU-39 Small Diameter Bombs (SDB), GBU-53/B SDB II, and SPEAR 3 ; up to four SDBs can be carried per station for the F-35A and F-35C, and three for the F-35B. The F-35A achieved certification to carry the B61 Mod 12 nuclear bomb in October 2023. The inboard station can carry the AIM-120 AMRAAM and eventually the AIM-260 JATM . Two compartments behind the weapons bays contain flares, chaff , and towed decoys. The aircraft can use six external weapons stations for missions that do not require stealth. The wingtip pylons each can carry an AIM-9X or AIM-132 ASRAAM and are canted outwards to reduce their radar cross-section. Additionally, each wing has

3638-625: The General Electric/Allison/Rolls-Royce F136 , was being developed in the 1990s and 2000s; originally, F-35 engines from Lot 6 onward were competitively tendered. Using technology from the General Electric YF120 , the F136 was claimed to have a greater temperature margin than the F135 due to the higher mass flow design making full use of the inlet. The F136 was canceled in December 2011 due to lack of funding. The F-35

3745-621: The Government Accountability Office (GAO) had identified major program risks in cost and schedule. The costly delays strained the relationship between the Pentagon and contractors. By 2017, delays and cost overruns had pushed the F-35 program's expected acquisition costs to $ 406.5 billion, with total lifetime cost (i.e., to 2070) to $ 1.5 trillion in then-year dollars which also includes operations and maintenance. The F-35A's unit cost (not including engine) for LRIP Lot 13

3852-753: The IEEE 1394b and Fibre Channel buses. The avionics use commercial off-the-shelf (COTS) components when practical to make upgrades cheaper and more flexible; for example, to enable fleet software upgrades for the software-defined radio (SDR) systems. The mission systems software, particularly for sensor fusion, was one of the program's most difficult parts and responsible for substantial program delays. The APG-81 radar uses electronic scanning for rapid beam agility and incorporates passive and active air-to-air modes, strike modes, and synthetic aperture radar (SAR) capability, with multiple target track-while-scan at ranges in excess of 80 nmi (150 km). The antenna

3959-737: The NASA X-43C , which was eventually canceled. The engine was applied to the AFRL's Scramjet Engine Demonstrator program in late 2003. The scramjet flight test vehicle was designated X-51 on 27 September 2005. In flight demonstrations, the X-51 is carried by a B-52 to an altitude of about 50,000 feet (15 km; 9.5 mi) and then released over the Pacific Ocean. The X-51 is initially propelled by an MGM-140 ATACMS solid rocket booster to approximately Mach 4.5 (3,000 mph; 4,800 km/h). The booster

4066-477: The toothed edges are rotated by motors, the nozzle swivels from being linear with the engine to being perpendicular . The thrust vectoring 3BSM nozzle allows the main engine exhaust to be deflected downward at the tail of the aircraft and is moved by a "fueldraulic" actuator that uses pressurized fuel as the working fluid . Unlike the Harrier's Pegasus engine that entirely uses direct engine thrust for lift,

4173-746: The ASTOVL/CALF canard configuration, which was designed without carrier compatibility in mind. This enabled greater commonality between all three variants, as the commonality goal was important at this design stage. Lockheed Martin's prototypes would consist of the X-35A for demonstrating CTOL before converting it to the X-35B for STOVL demonstration and the larger-winged X-35C for CV compatibility demonstration. The X-35A first flew on 24 October 2000 and conducted flight tests for subsonic and supersonic flying qualities, handling, range, and maneuver performance. After 28 flights,

4280-645: The Aerospace Systems Directorate within the U.S. Air Force Research Laboratory (AFRL). In the 1990s, the Air Force Research Laboratory (AFRL) began the HyTECH program for hypersonic propulsion . Pratt & Whitney received a contract from the AFRL to develop a hydrocarbon-fueled scramjet engine which led to the development of the SJX61 engine. The SJX61 engine was originally meant for

4387-556: The F-16, the F-35's sound power is stronger—particularly at lower frequencies. Subsequent surveys and studies have indicated that the noise of the F-35 was not perceptibly different from the F-16 and F/A-18E/F, though the greater low-frequency noise was noticeable for some observers. The glass cockpit was designed to give the pilot good situational awareness. The main display is a 20-by-8-inch (50 by 20 cm) panoramic touchscreen , which shows flight instruments, stores management, CNI information, and integrated caution and warnings;

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4494-543: The F-22; the F-35's radar-absorbent fibermat skin is more durable and requires less maintenance than older topcoats. The aircraft also has reduced infrared and visual signatures as well as strict controls of radio frequency emitters to prevent their detection. The F-35's stealth design is primarily focused on high-frequency X-band wavelengths; low-frequency radars can spot stealthy aircraft due to Rayleigh scattering , but such radars are also conspicuous, susceptible to clutter, and lack precision. To disguise its RCS,

4601-593: The F-24 designation for the JSF. As the JSF program moved into the System Development and Demonstration phase, the X-35 demonstrator design was modified to create the F-35 combat aircraft. The forward fuselage was lengthened by 5 inches (13 cm) to make room for mission avionics, while the horizontal stabilizers were moved 2 inches (5.1 cm) aft to retain balance and control. The diverterless supersonic inlet changed from

4708-406: The F-35 outside of official program contracts. In 2013, Northrop Grumman disclosed its development of a directional infrared countermeasures suite, named Threat Nullification Defensive Resource (ThNDR). The countermeasure system would share the same space as the Distributed Aperture System (DAS) sensors and acts as a laser missile jammer to protect against infrared-homing missiles. Israel operates

4815-443: The F-35's design, and radar cross-section (RCS) is minimized through careful shaping of the airframe and the use of radar-absorbent materials (RAM); visible measures to reduce RCS include alignment of edges and continuous curvature of surfaces, serration of skin panels, and the masking of the engine face and turbine. Additionally, the F-35's diverterless supersonic inlet (DSI) uses a compression bump and forward-swept cowl rather than

4922-598: The F-35's internal weapons bay eliminates drag from external stores. All variants have a top speed of Mach 1.6, attainable with full internal payload. The Pratt & Whitney F135 engine gives good subsonic acceleration and energy, with supersonic dash in afterburner. The F-35, while not a "supercruising" aircraft, can fly at Mach 1.2 for a dash of 150 miles (240 km) with afterburners. This ability can be useful in battlefield situations. The large stabilitors, leading edge extensions and flaps, and canted rudders provide excellent high alpha ( angle-of-attack ) characteristics, with

5029-407: The F-35A and C and externally on the B. Additionally, Lockheed Martin is studying integrating a fiber laser that uses spectral beam combining multiple individual laser modules into a single high-power beam, which can be scaled to various levels. The USAF plans for the F-35A to take up the close air support (CAS) mission in contested environments; amid criticism that it is not as well suited as

5136-438: The F-35B's system augments the swivel nozzle's thrust with the lift fan; the fan is powered by the low-pressure turbine through a drive shaft when engaged with a clutch and placed near the front of the aircraft to provide a torque countering that of the 3BSM nozzle. Roll control during slow flight is achieved by diverting unheated engine bypass air through wing-mounted thrust nozzles called roll posts. An alternative engine,

5243-424: The F-35B's weight by over 3,000 pounds (1,400 kg), while the F-35A and F-35C were reduced in weight by 2,400 pounds (1,100 kg) and 1,900 pounds (860 kg) respectively. The weight reduction work cost $ 6.2 billion and caused an 18-month delay. The first F-35A, designated AA-1, was rolled out at Fort Worth on 19 February 2006 and first flew on 15 December 2006 with chief test pilot Jon S. Beesley at

5350-564: The F-35C's larger wing is more fuel efficient. The fixed diverterless supersonic inlets (DSI) use a bumped compression surface and forward-swept cowl to shed the boundary layer of the forebody away from the inlets, which form a Y-duct for the engine. Structurally, the F-35 drew upon lessons from the F-22; composites comprise 35% of airframe weight, with the majority being bismaleimide and composite epoxy materials as well as some carbon nanotube -reinforced epoxy in later production lots. The F-35

5457-563: The F119, is not optimized for supercruise . The engine contributes to the F-35's stealth by having a low-observable augmenter, or afterburner , that incorporates fuel injectors into thick curved vanes; these vanes are covered by ceramic radar-absorbent materials and mask the turbine. The stealthy augmenter had problems with pressure pulsations, or "screech", at low altitude and high speed early in its development. The low-observable axisymmetric nozzle consists of 15 partially overlapping flaps that create

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5564-674: The JSF. The United Kingdom joined JAST/JSF as a founding member in 1995 and thus became the only Tier 1 partner of the JSF program; Italy, the Netherlands, Denmark, Norway, Canada, Australia, and Turkey joined the program during the Concept Demonstration Phase (CDP), with Italy and the Netherlands being Tier 2 partners and the rest Tier 3. Consequently, the aircraft was developed in cooperation with international partners and available for export. Boeing and Lockheed Martin were selected in early 1997 for CDP, with their concept demonstrator aircraft designated X-32 and X-35 respectively;

5671-495: The Joint Advanced Strike Technology (JAST) program emerged following the cancellation of the USAF's Multi-Role Fighter (MRF) and U.S. Navy's (USN) Advanced Attack/Fighter (A/F-X) programs. MRF, a program for a relatively affordable F-16 replacement, was scaled back and delayed due to post–Cold War defense posture easing F-16 fleet usage and thus extending its service life as well as increasing budget pressure from

5778-520: The McDonnell Douglas team was eliminated and Northrop Grumman and British Aerospace joined the Lockheed Martin team. Each firm would produce two prototype air vehicles to demonstrate conventional takeoff and landing (CTOL), carrier takeoff and landing (CV), and STOVL. Lockheed Martin's design would make use of the work on the SDLF system conducted under the ASTOVL/CALF program. The key aspect of

5885-401: The Pacific Ocean off Point Mugu for over six minutes of total flight time; this test was the longest air-breathing hypersonic flight. Researchers collected telemetry data for 370 seconds of flight. The test signified the completion of the program. The Air Force Research Laboratory believes the successful flight will serve as research for practical applications of hypersonic flight, such as

5992-569: The STOVL and CTOL variants, while the CV variant would have an enlarged wing to reduce landing speed for carrier recovery. Due to aerodynamic characteristics and carrier recovery requirements from the JAST merger, the design configuration settled on a conventional tail compared to the canard delta design from the ASTOVL/CALF; notably, the conventional tail configuration offers much lower risk for carrier recovery compared to

6099-546: The U.S. Air Force planned to apply X-51 technology to the High Speed Strike Weapon (HSSW), a missile similar in size to the X-51. The HSSW was expected to fly in 2020 and enter service in the mid-2020s. It was to have a range of 500–600 nautical miles (930–1,110 km), fly at Mach 5–6, and fit on an F-35 or in the internal bay of a B-2 bomber. Ground tests of the X-51A began in late 2005. A preliminary version of

6206-582: The USMC, and 273 F-35Cs for the USN. Additionally, the United Kingdom, Italy, the Netherlands, Turkey, Australia, Norway, Denmark and Canada have agreed to contribute US$ 4.375 billion towards development costs, with the United Kingdom contributing about 10% of the planned development costs as the sole Tier 1 partner. The initial plan was that the U.S. and eight major partner countries would acquire over 3,100 F-35s through 2035. The three tiers of international participation generally reflect financial stake in

6313-433: The United Kingdom, and formerly Turkey . Several other countries have also ordered, or are considering ordering, the aircraft. The program has drawn criticism for its unprecedented size, complexity, ballooning costs, and delayed deliveries. The acquisition strategy of concurrent production of the aircraft while it was still in development and testing led to expensive design changes and retrofits. As of July 2024 ,

6420-555: The X-35 that enabled STOVL operation, the SDLF system consists of the lift fan in the forward center fuselage that could be activated by engaging a clutch that connects the driveshaft to the turbines and thus augmenting the thrust from the engine's swivel nozzle. Research from prior aircraft incorporating similar systems, such as the Convair Model 200 , Rockwell XFV-12 , and Yakovlev Yak-141 , were also taken into consideration. By contrast, Boeing's X-32 employed direct lift system that

6527-528: The X-51, the "Ground Demonstrator Engine No. 2", completed wind tunnel tests at the NASA Langley Research Center on 27 July 2006. Testing continued there until a simulated X-51 flight at Mach 5 was successfully completed on 30 April 2007. The testing is intended to observe acceleration between Mach 4 and Mach 6 and to demonstrate that hypersonic thrust "isn't just luck". Four captive test flights were initially planned for 2009. However,

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6634-481: The aircraft can mount four Luneburg lens reflectors. Noise from the F-35 caused concerns in residential areas near potential bases for the aircraft, and residents near two such bases— Luke Air Force Base , Arizona, and Eglin Air Force Base (AFB), Florida—requested environmental impact studies in 2008 and 2009 respectively. Although the noise levels, in decibels, were comparable to those of prior fighters such as

6741-476: The aircraft was then converted into the X-35B for STOVL testing, with key changes including the addition of the SDLF, the three-bearing swivel module (3BSM), and roll-control ducts. The X-35B would successfully demonstrate the SDLF system by performing stable hover, vertical landing, and short takeoff in less than 500 ft (150 m). The X-35C first flew on 16 December 2000 and conducted field landing carrier practice tests. On 26 October 2001, Lockheed Martin

6848-473: The aircraft. The HMDS allows an F-35 pilot to fire missiles at targets even when the nose of the aircraft is pointing elsewhere by cuing missile seekers at high angles off-boresight. Each helmet costs $ 400,000. The HMDS weighs more than traditional helmets, and there is concern that it can endanger lightweight pilots during ejection. Due to the HMDS's vibration, jitter, night-vision and sensor display problems during development, Lockheed Martin and Elbit issued

6955-420: The amount of cooling available to support the additional mission systems. The engine upgrade effort explored both improvements to the F135 as well as significantly more power and efficient adaptive cycle engines . In 2018, General Electric and Pratt & Whitney were awarded contracts to develop adaptive cycle engines for potential application in the F-35, and in 2022, the F-35 Adaptive Engine Replacement program

7062-432: The anticipated commonality of 70%. The program received considerable criticism for cost overruns and for the total projected lifetime cost, as well as quality management shortcomings by contractors. As of August 2023 , the program was 80% over budget and 10 years late. The JSF program was expected to cost about $ 200 billion for acquisition in base-year 2002 dollars when SDD was awarded in 2001. As early as 2005,

7169-426: The augmented turbofan would be reconfigured to when engaging in STOVL operation. Lockheed Martin's commonality strategy was to replace the STOVL variant's SDLF with a fuel tank and the aft swivel nozzle with a two-dimensional thrust vectoring nozzle for the CTOL variant. STOVL operation is made possible through a patented shaft-driven LiftFan propulsion system. This would enable identical aerodynamic configuration for

7276-478: The average flyaway costs per plane are: US$ 82.5 million for the F-35A, $ 109 million for the F-35B, and $ 102.1 million for the F-35C. The F-35 first flew in 2006 and entered service with the U.S. Marine Corps F-35B in July 2015, followed by the U.S. Air Force F-35A in August 2016 and the U.S. Navy F-35C in February 2019. The aircraft was first used in combat in 2018 by the Israeli Air Force . The U.S. plans to buy 2,456 F-35s through 2044, which will represent

7383-478: The baseline Block 3F standard by 2021. With Block 3F as the final build for SDD, the first major upgrade program is Block 4 which began development in 2019 and was initially captured under the Continuous Capability Development and Delivery (C2D2) program. Block 4 is expected to enter service in incremental steps from the late 2020s to early 2030s and integrates additional weapons, including those unique to international customers, improved sensor capabilities including

7490-553: The bulk of the crewed tactical aviation of the U.S. Air Force, Navy, and Marine Corps for several decades; the aircraft is planned to be a cornerstone of NATO and U.S.-allied air power and to operate to 2070. The F-35 was the product of the Joint Strike Fighter (JSF) program, which was the merger of various combat aircraft programs from the 1980s and 1990s. One progenitor program was the Defense Advanced Research Projects Agency (DARPA) Advanced Short Take-Off/Vertical Landing (ASTOVL) which ran from 1983 to 1994; ASTOVL aimed to develop

7597-460: The cloud-based Operational Data Integrated Network (ODIN). From September 2020, ODIN base kits (OBKs) were running ALIS software, as well as ODIN software, first at Marine Corps Air Station (MCAS) Yuma, Arizona, then at Naval Air Station Lemoore, California, in support of Strike Fighter Squadron (VFA) 125 on 16 July 2021, and then Nellis Air Force Base, Nevada, in support of the 422nd Test and Evaluation Squadron (TES) on 6 August 2021. In 2022, over

7704-511: The controls. In 2006, the F-35 was given the name "Lightning II" after the Lockheed P-38 Lightning of World War II. Some USAF pilots have nicknamed the aircraft "Panther" instead, and other nicknames include "Fat Amy" and "Battle Penguin". The aircraft's software was developed as six releases, or Blocks, for SDD. The first two Blocks, 1A and 1B, readied the F-35 for initial pilot training and multi-level security. Block 2A improved

7811-472: The designations XA100 and XA101 respectively. In addition to potential re-engining, P&W is also developing improvements to the baseline F135; the Engine Core Upgrade (ECU) is an update to the power module, originally called Growth Option 1.0 and then Engine Enhancement Package, that improves engine thrust and fuel burn by 5% and bleed air cooling capacity by 50% to support Block 4. The F135 ECU

7918-408: The desired part; for instance, the ejection seat can be replaced without removing the canopy. The F-35 has a fibermat radar-absorbent material (RAM) baked into the skin, which is more durable, easier to work with, and faster to cure than older RAM coatings; similar coatings are being considered for application on older stealth aircraft such as the F-22. Skin corrosion on the F-22 led to the F-35 using

8025-405: The edges of the wing and tail for all-aspect radar warning receiver (RWR). It also provides sensor fusion of radio frequency and infrared tracking functions, geolocation threat targeting, and multispectral image countermeasures for self-defense against missiles. The electronic warfare system can detect and jam hostile radars. The AAQ-40 EOTS is mounted behind a faceted low-observable window under

8132-490: The first captive flight of the X-51A on a B-52 was conducted on 9 December 2009, with further flights in early 2010. The first powered flight of the X-51 was planned for 25 May 2010, but the presence of a cargo ship traveling through a portion of the Naval Air Station Point Mugu Sea Range caused a 24-hour delay. The X-51 completed its first powered flight successfully on 26 May 2010. It reached

8239-423: The first operational supersonic STOVL stealth fighter, the F-35 emphasizes low observables, advanced avionics and sensor fusion that enable a high level of situational awareness and long range lethality; the USAF considers the aircraft its primary strike fighter for conducting suppression of enemy air defense (SEAD) and air interdiction missions, owing to the advanced sensors and mission systems. The F-35 has

8346-423: The flight over the Pacific Ocean ended early due to an inlet unstart event after being boosted to Mach 5 speed. The flight data from the test was being investigated. A B-52 released the X-51 at an approximate altitude of 50,000 feet (15,000 m). The X-51's scramjet engine lit on ethylene , but did not properly transition to JP-7 fuel operation. The third test flight took place on 14 August 2012. The X-51

8453-566: The front and has an internal frame for structural strength. The Martin-Baker US16E ejection seat is launched by a twin-catapult system housed on side rails. There is a right-hand side stick and throttle hands-on throttle-and-stick system. For life support, an onboard oxygen-generation system (OBOGS) is fitted and powered by the Integrated Power Package (IPP), with an auxiliary oxygen bottle and backup oxygen system for emergencies. The Vision Systems International helmet display

8560-485: The integrity of the supply chain. Testing found several major problems: early F-35B airframes were vulnerable to premature cracking, the F-35C arrestor hook design was unreliable, fuel tanks were too vulnerable to lightning strikes, the helmet display had problems, and more. Software was repeatedly delayed due to its unprecedented scope and complexity. In 2009, the DoD Joint Estimate Team (JET) estimated that

8667-513: The need for concept demonstrator aircraft by 1996 emerged, which would coincide with the full-scale flight demonstrator phase of ASTOVL/CALF. Because the ASTOVL/CALF concept appeared to align with the JAST charter, the two programs were eventually merged in 1994 under the JAST name, with the program now serving the USAF, USMC, and USN. JAST was subsequently renamed to Joint Strike Fighter (JSF) in 1995, with STOVL submissions by McDonnell Douglas, Northrop Grumman , Lockheed Martin , and Boeing. The JSF

8774-457: The new AN/APG-85 AESA radar and additional ESM bandwidth, and adds Remotely Operated Video Enhanced Receiver ( ROVER ) support. C2D2 also places greater emphasis on agile software development to enable quicker releases. The key enabler of Block 4 is Technology Refresh 3 (TR-3) avionics hardware, which consists of new display, core processor, and memory modules to support increased processing requirements, as well as engine upgrade that increases

8881-610: The nose and performs laser targeting, forward-looking infrared (FLIR), and long range IRST functions. The ASQ-242 CNI suite uses a half dozen physical links, including the directional Multifunction Advanced Data Link (MADL), for covert CNI functions. Through sensor fusion, information from radio frequency receivers and infrared sensors are combined to form a single tactical picture for the pilot. The all-aspect target direction and identification can be shared via MADL to other platforms without compromising low observability , while Link 16 enables communication with older systems. The F-35

8988-402: The pilot can customize the arrangement of the information. Below the main display is a smaller stand-by display. The cockpit has a speech-recognition system developed by Adacel . The F-35 does not have a head-up display ; instead, flight and combat information is displayed on the visor of the pilot's helmet in a helmet-mounted display system (HMDS). The one-piece tinted canopy is hinged at

9095-700: The pilot's situational awareness and command-and-control capabilities and facilitate network-centric warfare . Key sensors include the Northrop Grumman AN/APG-81 active electronically scanned array (AESA) radar, BAE Systems AN/ASQ-239 Barracuda electronic warfare system, Northrop Grumman/ Raytheon AN/AAQ-37 Electro-optical Distributed Aperture System (DAS), Lockheed Martin AN/AAQ-40 Electro-Optical Targeting System (EOTS) and Northrop Grumman AN/ASQ-242 Communications, Navigation, and Identification (CNI) suite. The F-35

9202-432: The pod is mounted on the centerline of the aircraft and shaped to reduce its radar cross-section. In lieu of the gun, the pod can also be used for different equipment and purposes, such as electronic warfare , aerial reconnaissance , or rear-facing tactical radar. The pod was not susceptible to the accuracy issues that once plagued the gun on the F-35A variant, though was apparently not problem-free. Lockheed Martin

9309-508: The potential for the F-35 to orchestrate attacks by unmanned combat aerial vehicles (UCAVs) via its sensors and communications equipment. A new radar called the AN/APG-85 is planned for Block 4 F-35s. According to the JPO, the new radar will be compatible with all three major F-35 variants. However, it is unclear if older aircraft will be retrofitted with the new radar. Stealth is a key aspect of

9416-518: The program was 30 months behind the public schedule. In 2011, the program was "re-baselined"; that is, its cost and schedule goals were changed, pushing the IOC from the planned 2010 to July 2015. The decision to simultaneously test, fix defects, and begin production was criticized as inefficient; in 2014, Under Secretary of Defense for Acquisition Frank Kendall called it "acquisition malpractice". The three variants shared just 25% of their parts, far below

9523-437: The program, the amount of technology transfer and subcontracts open for bid by national companies, and the order in which countries can obtain production aircraft. Alongside program partner countries, Israel and Singapore have joined as Security Cooperative Participants (SCP). Sales to SCP and non-partner states, including Belgium, Japan, and South Korea, are made through the Pentagon's Foreign Military Sales program. Turkey

9630-420: The same flight trajectory . Boeing proposed to the Air Force Research Laboratory (AFRL) that two test flights be added to increase the total to six, with flights taking place at four to six week intervals, provided there are no failures. The second test flight was initially scheduled for 24 March 2011, but was not conducted due to unfavorable test conditions. The flight took place on 13 June 2011. However,

9737-447: The same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=X51&oldid=545739856 " Category : Letter–number combination disambiguation pages Hidden categories: Short description

9844-499: The scramjet engine could ignite. On 1 May 2013, the X-51 performed its first fully successful flight test on its fourth test flight. The X-51 and booster detached from a B-52H and was powered to Mach 4.8 (3,200 mph; 5,100 km/h) by the booster rocket. It then separated cleanly from the booster and ignited its own engine. The test aircraft then accelerated to Mach 5.1 (3,400 mph; 5,400 km/h) and flew for 210 seconds until running out of fuel and plunging into

9951-469: The systems of a fighter aircraft added weight. The F-35B gained the most, largely due to a 2003 decision to enlarge the weapons bays for commonality between variants; the total weight growth was reportedly up to 2,200 pounds (1,000 kg), over 8%, causing all STOVL key performance parameter (KPP) thresholds to be missed. In December 2003, the STOVL Weight Attack Team (SWAT) was formed to reduce

10058-526: The training capabilities, while 2B was the first combat-ready release planned for the USMC's Initial Operating Capability (IOC). Block 3i retains the capabilities of 2B while having new Technology Refresh 2 (TR-2) hardware and was planned for the USAF's IOC. The final release for SDD, Block 3F, would have full flight envelope and all baseline combat capabilities. Alongside software releases, each block also incorporates avionics hardware updates and air vehicle improvements from flight and structural testing. In what

10165-523: The weight increase; changes included thinned airframe members, smaller weapons bays and vertical stabilizers, less thrust fed to the roll-post outlets, and redesigning the wing-mate joint, electrical elements, and the airframe immediately aft of the cockpit. The inlet was also revised to accommodate more powerful, greater mass flow engines. Many changes from the SWAT effort were applied to all three variants for commonality. By September 2004, these efforts had reduced

10272-555: Was $ 79.2 million in base-year 2012 dollars. Delays in development and operational test and evaluation, including integration into the Joint Simulation Environment, pushed full-rate production decision from the end of 2019 to March 2024, although actual production rate had already approached the full rate by 2020; the combined full rate at the Fort Worth, Italy, and Japan FACO plants is 156 aircraft annually. The F-35

10379-668: Was a single-engine canard delta aircraft weighing about 24,000 lb (11,000 kg) empty. ASTOVL was rechristened as the Common Affordable Lightweight Fighter (CALF) in 1993 and involved Lockheed , McDonnell Douglas , and Boeing . The end of the Cold War and the collapse of the Soviet Union in 1991 caused considerable reductions in Department of Defense (DoD) spending and subsequent restructuring. In 1993,

10486-475: Was declared the winner and was awarded the System Development and Demonstration (SDD) contract; Pratt & Whitney was separately awarded a development contract for the F135 engine for the JSF. The F-35 designation, which was out of sequence with standard DoD numbering , was allegedly determined on the spot by program manager Major General Mike Hough; this came as a surprise even to Lockheed Martin, which had expected

10593-630: Was designed for its sensors to work together to provide a cohesive image of the local battlespace ; for example, the APG-81 radar also acts as a part of the electronic warfare system. Much of the F-35's software was developed in C and C++ programming languages , while Ada83 code from the F-22 was also used; the Block 3F software has 8.6 million lines of code . The Green Hills Software Integrity DO-178B real-time operating system (RTOS) runs on integrated core processors (ICPs); data networking includes

10700-516: Was designed to accept upgrades to its processors, sensors, and software over its lifespan. Technology Refresh 3, which includes a new core processor and a new cockpit display, is planned for Lot 15 aircraft. Lockheed Martin has offered the Advanced EOTS for the Block 4 configuration; the improved sensor fits into the same area as the baseline EOTS with minimal changes. In June 2018, Lockheed Martin picked Raytheon for improved DAS. The USAF has studied

10807-505: Was expected to eventually replace large numbers of multi-role and strike fighters in the inventories of the US and its allies, including the Harrier, F-16, F/A-18 , A-10 , and F-117 . International participation is a key aspect of the JSF program, starting with United Kingdom participation in the ASTOVL program. Many international partners requiring modernization of their air forces were interested in

10914-402: Was initially supported by a computerized maintenance management system named Autonomic Logistics Information System (ALIS). In concept, any F-35 can be serviced at any maintenance facility and all parts can be globally tracked and shared as needed. Due to numerous problems, such as unreliable diagnoses, excessive connectivity requirements, and security vulnerabilities , ALIS is being replaced by

11021-694: Was introduced with LRIP lot 7. To preserve its stealth shaping, the F-35 has two internal weapons bays each with two weapons stations. The two outboard weapon stations each can carry ordnance up to 2,500 lb (1,100 kg), or 1,500 lb (680 kg) for the F-35B, while the two inboard stations carry air-to-air missiles. Air-to-surface weapons for the outboard station include the Joint Direct Attack Munition (JDAM), Paveway series of bombs, Joint Standoff Weapon (JSOW), and cluster munitions ( Wind Corrected Munitions Dispenser ). The station can also carry multiple smaller munitions such as

11128-502: Was launched to integrate them. However, in 2023 the USAF chose an improved F135 under the Engine Core Upgrade (ECU) program over an adaptive cycle engine due to cost as well as concerns over risk of integrating the new engine, initially designed for the F-35A, on the B and C. Difficulties with the new TR-3 hardware, including regression testing , have caused delays to Block 4 as well as a halt in aircraft deliveries from July 2023 to July 2024. Defense contractors have offered upgrades to

11235-458: Was removed from the F-35 program in July 2019 over security concerns following its purchase of a Russian S-400 surface-to-air missile system. As of July 2024 , the average flyaway costs per plane are: $ 82.5 million for the F-35A, $ 109 million for the F-35B, and $ 102.1 million for the F-35C. The F-35 is a family of single-engine, supersonic, stealth multirole strike fighters. The second fifth-generation fighter to enter US service and

11342-551: Was selected over AETP engines in 2023 to provide additional power and cooling for the F-35. Although GE had expected that the more revolutionary XA100 could enter service with the F-35A and C by 2027 and could be adapted for the F-35B, the increased cost and risk caused the USAF to choose the F135 ECU instead. The F-35 is designed to require less maintenance than prior stealth aircraft. Some 95% of all field-replaceable parts are "one deep"—that is, nothing else needs to be removed to reach

11449-505: Was to make a 300-second (5 minutes) experimental flight at speeds of Mach 5 (3,300 mph; 5,300 km/h). After separating from its rocket booster, the craft lost control and crashed into the Pacific. The Air Force Research Laboratory (AFRL) determined the problem was the X-51's upper right aerodynamic fin unlocked during flight and became uncontrollable; all four fins are needed for aerodynamic control. The aircraft lost control before

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