Lockheed Martin F-35 Lightning II
The Lockheed Martin F-35 Lightning II is an American family of single-seat, single-engine, all-weather stealth multirole combat aircraft that is intended to perform both air superiority and strike missions. It is also able to provide electronic warfare and intelligence, surveillance, and reconnaissance capabilities. Lockheed Martin 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-based (CV/CATOBAR) F-35C.
|F-35 Lightning II|
|A U.S. Air Force F-35A|
|Role||Stealth multirole fighter|
|National origin||United States|
|First flight||15 December 2006 (F-35A)|
|Introduction||F-35B: 31 July 2015 (USMC)|
F-35A: 2 August 2016 (USAF)
F-35C: 28 February 2019 (USN)
|Primary users||United States Air Force|
United States Marine Corps
United States Navy
Royal Air Force
See Operators section for others
|Number built||625+ as of April 1, 2021|
|Developed from||Lockheed Martin X-35|
The aircraft descends from the Lockheed Martin X-35, which in 2001 beat the Boeing X-32 to win the Joint Strike Fighter (JSF) program. Its development is principally funded by the United States, with additional funding from program partner countries from NATO and close U.S. allies, including the United Kingdom, Australia, Canada, Italy, Norway, Denmark, the Netherlands, and formerly Turkey. Several other countries have ordered, or are considering ordering, the aircraft. The program has drawn much scrutiny and criticism for its unprecedented size, complexity, ballooning costs, and much-delayed deliveries, with numerous technical flaws still being corrected. The acquisition strategy of concurrent production of the aircraft while it was still in development and testing led to expensive design changes and retrofits.
The F-35B entered service with the U.S. Marine Corps 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 F-35 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 the bulk of the crewed tactical airpower of the U.S. Air Force, Navy, and Marine Corps for several decades. The aircraft is projected to operate until 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 a Harrier Jump Jet replacement for the U.S. Marine Corps (USMC) and the U.K. 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; a key technology explored was the shaft-driven lift fan (SDLF) system. Lockheed's concept 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.
In 1993, 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 Fighter-Attack (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 the F-22 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), an offshoot of USAF's Advanced Tactical Fighter (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 Department of Defense's (DoD) 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, maturing technologies, and demonstrating concepts for advanced strike warfare.
As JAST progressed, 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 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 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; 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 leverage the work on the SDLF system conducted under the ASTOVL/CALF program. The key aspect of 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 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. This would enable identical aerodynamic configuration for the STOVL and CTOL variants, while the CV variant would have an enlarged wing in order to reduce landing speed for carrier recovery. Due to aerodynamic characteristics and carrier recovery requirements from the JAST merger, the design configuration would settle 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 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 still important at this stage of the design. 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, 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 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 the "F-24" designation for the JSF.
Design and production
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 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 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). Prime contractor Lockheed Martin performs overall systems integration and final assembly and checkout (FACO), while Northrop Grumman and BAE Systems supply components for mission systems and airframe.
Adding 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 the weight increase; changes included more engine thrust, 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. Many changes from the SWAT effort were applied to all three variants for commonality. By September 2004, these efforts had reduced 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 in Fort Worth, Texas, on 19 February 2006 and first flew on 15 December 2006. The aircraft was given the name "Lightning II" in 2006.
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 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 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 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 the integrity of the supply chain.
Testing found several major problems: early F-35B airframes had 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 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 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.
The JSF program was expected to cost about $200 billion in base-year 2002 dollars when SDD was awarded in 2001. As early as 2005, 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 unit cost of LRIP lot 13 F-35A was $79.2 million. Delays in development and operational test and evaluation pushed full-rate production to 2021.
Upgrades and further development
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, the completion of which will conclude SDD. The F-35 program is also conducting sustainment and upgrade development, with early LRIP aircraft gradually upgraded to the baseline Block 3F standard by 2021.
The F-35 is expected to be continually upgraded over its lifetime. The first upgrade program, called Continuous Capability Development and Delivery (C2D2) began in 2019 and is currently planned to run to 2024. The near-term development priority of C2D2 is Block 4, which would integrate additional weapons, including those unique to international customers, refresh the avionics, improve ESM capabilities, and add Remotely Operated Video Enhanced Receiver (ROVER) support. C2D2 also places greater emphasis on agile software development to enable quicker releases. In 2018, the Air Force Life Cycle Management Center (AFLCMC) awarded contracts to General Electric and Pratt & Whitney to develop more powerful and efficient adaptive cycle engines for potential application in the F-35, leveraging the research done under the Adaptive Engine Transition Program (AETP).
Defense contractors have offered upgrades to the F-35 outside of official program contracts. In 2013, Northrop Grumman disclosed its development of a directional infrared countermeasures (DIRCM) 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.
Procurement and international participation
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 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 nations would acquire over 3,100 F-35s through 2035. The three tiers of international participation generally reflect financial stake in 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 nations, including Belgium, Japan, and South Korea, are made through the Pentagon's Foreign Military Sales program. Turkey was removed from the F-35 program in July 2019 over security concerns.
In December 2011 Japan announced its intention to purchase 42 F-35s to replace the F-4 Phantom II, with 38 to be assembled domestically and deliveries beginning in 2016. Due to delays in development and testing, many initial orders have been postponed. Italy reduced its order from 131 to 90 F-35s in 2012. Australia decided to buy the F/A-18F Super Hornet in 2006 and the EA-18G Growler in 2013 as interim measures.
On 3 April 2012, the Auditor General of Canada published a report outlining problems with Canada's procurement of the jet; the report states that the government knowingly understated the final cost of 65 F-35s by $10 billion. Following the 2015 Federal Election, the Canadian government under the Liberal Party decided not to proceed with a sole-sourced purchase and launched a competition to choose an aircraft.
In January 2019, Singapore announced its plan to buy a small number of F-35s for an evaluation of capabilities and suitability before deciding on more to replace its F-16 fleet. In May 2019, Poland announced plans to buy 32 F-35As to replace its Soviet-era jets; the contract was signed in January 2020.
The F-35 is a family of single-engine, supersonic, stealth multirole fighters. The second fifth generation fighter to enter US service and 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) missions, owing to the advanced sensors and mission systems.
The F-35 has 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 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; 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 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 raw performance of the larger twin-engine F-22, the F-35 has kinematics competitive with fourth generation fighters such as the F-16 and F/A-18, especially with ordnance mounted because the F-35's internal weapons carriage eliminates parasitic drag from external stores. All variants have a top speed of Mach 1.6, attainable with full internal payload. The powerful F135 engine gives good subsonic acceleration and energy, with supersonic dash in afterburner. The large stabilitors, leading edge extensions and flaps, and canted rudders provide excellent high alpha (angle-of-attack) characteristics, with a trimmed alpha of 50°. Relaxed stability and fly-by-wire controls provide excellent handling qualities and departure resistance. Having over double the F-16's internal fuel, the F-35 has considerably greater combat radius, while stealth also enables a more efficient mission flight profile.
Sensors and avionics
The F-35's mission systems are among the most complex aspects of the aircraft. The avionics and sensor fusion are designed to enhance 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 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 was designed with sensor intercommunication to provide a cohesive image of the local battlespace and availability for any possible use and combination with one another; 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 the IEEE 1394b and Fibre Channel buses. To enable fleet software upgrades for the software-defined radio systems and greater upgrade flexibility and affordability, the avionics leverage commercial off-the-shelf (COTS) components when practical. 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 tracking at ranges in excess of 80 nmi (150 km). The antenna 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 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 is capable of detecting and jamming hostile radars. The AAQ-40 EOTS is mounted internally behind a faceted low-observable window under the nose and performs laser targeting, forward-looking infrared (FLIR), and long range IRST functions. The ASQ-242 CNI suite uses a half dozen different physical links, including the 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 is present for communication with legacy systems.
The F-35 was designed from the outset to incorporate improved processors, sensors, and software enhancements 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 the potential for the F-35 to orchestrate attacks by unmanned combat aerial vehicles (UCAVs) via its sensors and communications equipment.
Stealth and signatures
Stealth is a key aspect of 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, 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 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 learned from prior stealth aircraft such as 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, 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 level in decibels were comparable to those of prior fighters such as the F-16, the sound power of the F-35 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; 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 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 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 he or she is 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" 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 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 was introduced with LRIP lot 7.
To preserve its stealth shaping, the F-35 has two internal weapons bays with four 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 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 the GBU-39 Small Diameter Bombs (SDB), GBU-53/B SDB II, and SPEAR 3 anti-tank missiles; up to four SDBs can be carried per station for the F-35A and F-35C, and three for the F-35B. The inboard station can carry the AIM-120 AMRAAM. 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 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 Stand-off Missile (JASSM) cruise missile. An air-to-air missile load of eight AIM-120s and two AIM-9s 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-35A is armed with a 25 mm GAU-22/A rotary cannon mounted internally near the left wing root with 182 rounds carried; the gun is more effective against ground targets than the 20 mm cannon carried by other USAF fighters. 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; 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.
Lockheed Martin 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 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. Nuclear weapons delivery via internal carriage of the B61 nuclear bomb is planned for Block 4B in 2024. Both hypersonic missiles and direct energy weapons such as solid-state laser are currently being considered as future upgrades. 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 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 a strafing run.
The single-engine aircraft is powered by the Pratt & Whitney F135 low-bypass augmented turbofan with rated thrust of 43,000 lbf (191 kN). Derived from the Pratt & Whitney F119 used by the F-22, the F135 has a larger fan and higher bypass ratio to increase subsonic fuel efficiency, and unlike 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 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 USN had to modify its underway replenishment system to facilitate at-sea logistics support.
The F135-PW-600 variant for the F-35B incorporates the 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 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, 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 counterbalancing thrust. Roll control during slow flight is achieved by diverting unheated engine bypass air through wing-mounted thrust nozzles called roll posts.
An alternative engine, the General Electric/Rolls-Royce F136, was being developed in the 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. The F136 was canceled in December 2011 due to lack of funding.
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. Both GE and P&W were awarded contracts to develop 45,000 lbf (200 kN) class demonstrators, with the designations XA100 and XA101 respectively. In 2017, P&W announced the F135 Growth Option 1.0 and 2.0; Growth Option 1.0, which had finished testing and was production ready in May 2017, was a power module upgrade that offered 6–10% thrust improvement and 5–6% fuel burn reduction. The power module could be retrofitted onto older engines and seamlessly added to future engines at low cost rise and no impact on delivery. Growth Option 2.0 would be the adaptive cycle XA101. In June 2018, Pratt & Whitney changed its development plan for the F135, and instead offered an adaptive three-stream fan as Growth Option 2.0 that's separate from the XA101, which would instead have a new engine core.
Maintenance and logistics
The F-35 is designed to require less maintenance than earlier stealth aircraft. Some 95% of all field-replaceable parts are "one deep"—that is, nothing else need be removed to reach 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 currently being considered for application on older stealth aircraft such as the F-22. Skin corrosion on the F-22 led the F-35's designers to use a less galvanic corrosion-inducing skin gap filler and to use 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 the different variants allowed the USMC to create their first aircraft maintenance Field Training Detachment to apply the USAF's lessons to their F-35 operations.
The F-35 was intended to be supported by a computerized maintenance management system named Autonomic Logistics Information System (ALIS). In concept, any aircraft can be serviced at any F-35 maintenance facility and for all parts to be globally tracked and shared as needed. Due to numerous problems, such as unreliable diagnoses, excessive connectivity requirements, and security vulnerabilities, program officials plan to replace ALIS with the cloud-based Operational Data Integrated Network (ODIN) by 2022.
The first F-35A, AA-1, conducted its engine run in September 2006 and first flew on 15 December 2006. Unlike all subsequent aircraft, AA-1 did not have the weight optimization from SWAT; consequently, it mainly tested subsystems common to subsequent aircraft, such as the propulsion, electrical system, and cockpit displays. This aircraft was retired from flight testing in December 2009 and was used for live-fire testing at NAS China Lake.
The first F-35B, BF-1, flew on 11 June 2008, while the first weight-optimized F-35A and F-35C, AF-1 and CF-1, flew on 14 November 2009 and 6 June 2010 respectively. The F-35B's first hover was on 17 March 2010, followed by its first vertical landing the next day. The F-35 Integrated Test Force (ITF) consisted of 18 aircraft at Edwards Air Force Base and Naval Air Station Patuxent River. Nine aircraft at Edwards, five F-35As, three F-35Bs, and one F-35C, performed flight sciences testing such as F-35A envelope expansion, flight loads, stores separation, as well as mission systems testing. The other nine aircraft at Patuxent River, five F-35Bs and four F-35Cs, were responsible for F-35B and C envelope expansion and STOVL and CV suitability testing. Additional carrier suitability testing was conducted at Naval Air Warfare Center Aircraft Division at Lakehurst, New Jersey. Two non-flying aircraft of each variant were used to test static loads and fatigue. For testing avionics and mission systems, a modified Boeing 737-300 with a duplication of the cockpit, the Lockheed Martin CATBird has been used. Field testing of the F-35's sensors were conducted during Exercise Northern Edge 2009 and 2011, serving as significant risk-reduction steps.
Flight tests revealed several serious deficiencies that required costly redesigns, caused delays, and resulted in several fleet-wide groundings. In 2011, the F-35C failed to catch the arresting wire in all eight landing tests; a redesigned tail hook was delivered two years later. By June 2009, many of the initial flight test targets had been accomplished but the program was behind schedule. Software and mission systems were among the biggest sources of delays for the program, with sensor fusion proving especially challenging. In fatigue testing, the F-35B suffered several premature cracks, requiring a redesign of the structure. A third non-flying F-35B is currently planned to test the redesigned structure. The F-35B and C also had problems with the horizontal tails suffering heat damage from prolonged afterburner use. Early flight control laws had problems with "wing drop" and also made the airplane sluggish, with high angles-of-attack tests in 2015 against an F-16 showing a lack of energy.
At-sea testing of the F-35B was first conducted aboard USS Wasp. In October 2011, two F-35Bs conducted three weeks of initial sea trials, called Development Test I. The second F-35B sea trials, Development Test II, began in August 2013, with tests including nighttime operations; two aircraft completed 19 nighttime vertical landings using DAS imagery. The first operational testing involving six F-35Bs was done on the Wasp in May 2015. The final Development Test III on USS America involving operations in high sea states was completed in late 2016. A Royal Navy F-35 conducted the first "rolling" landing on board HMS Queen Elizabeth in October 2018.
After the redesigned tail hook arrived, the F-35C's carrier-based Development Test I began in November 2014 aboard USS Nimitz and focused on basic day carrier operations and establishing launch and recovery handling procedures. Development Test II, which focused on night operations, weapons loading, and full power launches, took place in October 2015. The final Development Test III was completed in August 2016, and included tests of asymmetric loads and certifying systems for landing qualifications and interoperability. Operational test of the F-35C began in 2018.
The F-35's reliability and availability have fallen short of requirements, especially in the early years of testing. The ALIS maintenance and logistics system was plagued by excessive connectivity requirements and faulty diagnoses. In late 2017, the GAO reported the time needed to repair an F-35 part averaged 172 days, which was "twice the program's objective," and that shortage of spare parts was degrading readiness. In 2019, while individual F-35 units have achieved mission-capable rates of over the target of 80% for short periods during deployed operations, fleet-wide rates remained below target. The fleet availability goal of 65% was also not met, although the trend shows improvement. Gun accuracy of the F-35A remains unacceptable. As of 2020, the number of the program's most serious issues have been decreased by half.
The F-35A and F-35B were cleared for basic flight training in early 2012. However, lack of system maturity at the time led to concerns over safety as well as concerns by the Director of Operational Test & Evaluation (DOT&E) over electronic warfare testing, budget, and concurrency for the Operational Test and Evaluation master plan. Nevertheless, on 10 September 2012, the USAF began an operational utility evaluation (OUE) of the F-35A, including logistical support, maintenance, personnel training, and pilot execution. OUE flights began on 26 October and were completed on 14 November after 24 flights, each pilot having completed six flights. On 16 November 2012, the USMC received the first F-35B at MCAS Yuma, although Marine pilots had several flight restrictions. During the Low Rate Initial Production (LRIP) phase, the three U.S. military services jointly developed tactics and procedures using flight simulators, testing effectiveness, discovering problems and refining design. In January 2013, training began at Eglin AFB with capacity for 100 pilots and 2,100 maintainers at once. On 8 January 2015, RAF Lakenheath in the UK was chosen as the first base in Europe to station two USAF F-35 squadrons, with 48 aircraft adding to the 48th Fighter Wing's existing F-15C and F-15E squadrons.
The USMC declared Initial Operational Capability (IOC) for the F-35B in the Block 2B configuration on 31 July 2015 after operational trials. However, limitations remained in night operations, communications, software and weapons carriage capabilities. USMC F-35Bs participated in their first Red Flag exercise in July 2016 with 67 sorties conducted. USAF F-35A in the Block 3i configuration achieved IOC with the USAF on 2 August 2016, and the F-35C in Block 3F with the USN on 28 February 2019. USAF F-35As conducted their first Red Flag exercise in 2017; system maturity had improved and the aircraft scored a kill ratio of 15:1 against an F-16 aggressor squadron in a high-threat environment.
The F-35's operating cost is higher than those of some older fighters. In fiscal year 2018, the F-35A's cost per flight hour (CPFH) was $44,000, a number that was reduced to $35,000 in 2019. For comparison, in 2015 the CPFH of the A-10 was $17,716; the F-15C, $41,921; and the F-16C, $22,514. Lockheed Martin hopes to reduce it to $25,000 by 2025 through performance-based logistics and other measures.
The USMC plans to disperse its F-35Bs among forward-deployed bases to enhance survivability while remaining close to a battlespace, similar to RAF Harrier deployment in the Cold War, which relied on the use of off-base locations that offered short runways, shelter, and concealment. Known as distributed STOVL operations (DSO), F-35Bs would operate from temporary bases in allied territory within the range of hostile ballistic and cruise missiles and be moved between temporary locations inside the enemy's 24- to 48-hour targeting cycle; this strategy accounts for the F-35B's short range, the shortest of the three variants, with mobile forward arming and refueling points (M-Farps) accommodating KC-130 and MV-22 Osprey aircraft to rearm and refuel the jets, as well as littoral areas for sea links of mobile distribution sites. M-Farps can be based on small airfields, multi-lane roads, or damaged main bases, while F-35Bs return to rear-area USAF bases or friendly ships for scheduled maintenance. Helicopter-portable metal planking is needed to protect unprepared roads from the F-35B's engine exhaust; the USMC are studying lighter heat-resistant alternatives.
The first U.S. combat employment began in July 2018 with USMC F-35Bs from the amphibious assault ship USS Essex, with the first combat strike on 27 September 2018 against a Taliban target in Afghanistan. This was followed by a USAF deployment to Al Dhafra Air Base, UAE on 15 April 2019. On 27 April 2019, USAF F-35As were first used in combat in an airstrike on an Islamic State tunnel network in northern Iraq.
The United Kingdom's Royal Air Force and Royal Navy both operate the F-35B, known simply as the Lightning in British service; it has replaced the Harrier GR9, which was retired in 2010, and Tornado GR4, which was retired in 2019. The F-35 is to be Britain's primary strike aircraft for the next three decades. One of the Royal Navy's requirements for the F-35B was a Shipborne Rolling and Vertical Landing (SRVL) mode to increase maximum landing weight by using wing lift during landing. In July 2013, Chief of the Air Staff, Air Chief Marshal Sir Stephen Dalton announced that No. 617 (The Dambusters) Squadron would be the RAF's first operational F-35 squadron. The second operational squadron will be the Fleet Air Arm's 809 Naval Air Squadron in April 2023.
No. 17 (Reserve) Test and Evaluation Squadron (TES) stood-up on 12 April 2013 as the Operational Evaluation Unit for the Lightning, becoming the first British squadron to operate the type. By June 2013, the RAF had received three F-35s of the 48 on order, all initially based at Eglin Air Force Base. In June 2015, the F-35B undertook its first launches from a ski-jump at NAS Patuxent River. When operated at sea, British F-35B shall use ships fitted with ski-jumps, as will the Italian Navy. British F-35Bs are not intended to receive the Brimstone 2 missile. On 5 July 2017, it was announced the second UK-based RAF squadron would be No. 207 Squadron, which reformed on 1 August 2019 as the Lightning Operational Conversion Unit. No. 617 Squadron reformed on 18 April 2018 during a ceremony in Washington, D.C., US, becoming the first RAF front-line squadron to operate the type; receiving its first four F-35Bs on 6 June, flying from MCAS Beaufort to RAF Marham. Both No. 617 Squadron and its F-35s were declared combat ready on 10 January 2019.
In April 2019, No. 617 Squadron deployed to RAF Akrotiri, Cyprus, the type's first overseas deployment. On 25 June 2019, the first combat use of an RAF F-35B was reportedly undertaken as armed reconnaissance flights searching for Islamic State targets in Iraq and Syria. In October 2019, the Dambusters and No. 17 TES F-35s were embarked on HMS Queen Elizabeth for the first time. No. 617 Squadron departed RAF Marham on 22 January 2020 for their first Exercise Red Flag with the Lightning.
Australia’s first F-35, designated A35-001, was manufactured in 2014, with flight training provided through international Pilot Training Centre (PTC) at Luke Air Force Base in Arizona. The first two F-35s were unveiled to the Australian public on 3 March 2017 at the Avalon Airshow. By 2021, the Royal Australian Air Force had accepted 26 F-35A aircraft, with nine in the US and 17 operating at No 3 Squadron and No 2 Operational Conversion Unit at RAAF Base Williamtown. With 41 trained RAAF pilots and 225 trained technicians for maintenance, the fleet was declared ready to deploy on operations. It's expected that Australia will receive all 72 of the F-35s by 2023.
The Israeli Air Force declared the F-35 operationally capable on 6 December 2017. According to Kuwaiti newspaper Al Jarida, in July 2018, a test mission of at least three IAF F-35s flew to Iran's capital Tehran and back from Tel Aviv. While publicly unconfirmed, regional leaders acted on the report; Iran's supreme leader Ali Khamenei reportedly fired the air force chief and commander of Iran's Revolutionary Guard Corps over the mission.
On 22 May 2018, Israeli Air Force chief Amikam Norkin said that the service had employed their F-35Is in two attacks on two battle fronts, marking the first combat operation of an F-35 by any country. Norkin said it had been flown "all over the Middle East", and showed photos of an F-35I flying over Beirut in daylight. In July 2019, Israel reportedly expanded its strikes against Iranian missile shipments; IAF F-35Is allegedly struck Iranian targets in Iraq twice.
In November 2020 the Israeli Air Force announced the delivery of an F-35I Testbed aircraft amongst a delivery of four aircraft received in August. This example will be used to test and integrate Israeli-produced weapons and electronic systems on future F-35's received. This is the only example of a testbed F-35 delivered to an air force outside of the United States.
In February 2021 the Israeli Knesset approved the purchase of a third squadron of F-35's along with four KC-46 Pegasus tanking aircraft and assorted advanced aircraft munitions.
The F-35 was designed with three initial variants - the F-35A, a CTOL land-based version; the F-35B, a STOVL version capable of use either on land or on aircraft carriers; and the F-35C, a CATOBAR carrier-based version. Since then, there has been work on the design of nationally specific versions for Israel and Canada, as well as initial concept design work for an updated version of the F-35A, which would become the F-35D.
The F-35A is the conventional takeoff and landing (CTOL) variant intended for the USAF and other air forces. It is the smallest, lightest version and capable of 9 g, the highest of all variants.
Although the F-35A currently conducts aerial refueling via boom and receptacle method, the aircraft can be modified for probe-and-drogue refueling if needed by the customer. A drag chute pod can be installed on the F-35A, with the Royal Norwegian Air Force being the first operator to adopt it.
The F-35B is the short takeoff and vertical landing (STOVL) variant of the aircraft. Similar in size to the A variant, the B sacrifices about a third of the A variant's fuel volume to accommodate the SDLF. This variant is limited to 7 g. Unlike other variants, the F-35B has no landing hook. The "STOVL/HOOK" control instead engages conversion between normal and vertical flight. The F-35B can also perform vertical and/or short take-off and landing (V/STOL).
The F-35C variant is designed for catapult-assisted take-off but arrested recovery operations from aircraft carriers. Compared to the F-35A, the F-35C features larger wings with foldable wingtip sections, larger control surfaces for improved low-speed control, stronger landing gear for the stresses of carrier arrested landings, a twin-wheel nose gear, and a stronger tailhook for use with carrier arrestor cables. The larger wing area allows for decreased landing speed while increasing both range and payload. The F-35C is limited to 7.5 g.
The F-35I Adir (Hebrew: אדיר, meaning "Awesome", or "Mighty One") is an F-35A with unique Israeli modifications. The US initially refused to allow such changes before permitting Israel to integrate its own electronic warfare systems, including sensors and countermeasures. The main computer has a plug-and-play function for add-on systems; proposals include an external jamming pod, and new Israeli air-to-air missiles and guided bombs in the internal weapon bays. A senior IAF official said that the F-35's stealth may be partly overcome within 10 years despite a 30 to 40 year service life, thus Israel's insistence on using their own electronic warfare systems. Israel Aerospace Industries (IAI) has considered a two-seat F-35 concept; an IAI executive noted: "There is a known demand for two seats not only from Israel but from other air forces". IAI plans to produce conformal fuel tanks.
The Canadian CF-35 is a proposed variant that would differ from the F-35A through the addition of a drogue parachute and may include an F-35B/C-style refueling probe. In 2012, it was revealed that the CF-35 would employ the same boom refueling system as the F-35A. One alternative proposal would have been the adoption of the F-35C for its probe refueling and lower landing speed; however, the Parliamentary Budget Officer's report cited the F-35C's limited performance and payload as being too high a price to pay. Following the 2015 Federal Election the Liberal Party, whose campaign had included a pledge to cancel the F-35 procurement, formed a new government and commenced an open competition to replace the existing CF-18 Hornet.
- Israeli Air Force – 27 delivered as of May 2021 (F-35I "Adir"). Includes one F-35 Testbed aircraft for indigenous Israeli weapons and electronics upgrades, designated (AS-15). A total of 50 ordered with 75 planned.
- Italian Air Force – 12 F-35As delivered as of May 2020. 1 F-35B delivered as of October 2020, at which point Italy planned to order 60 F-35As and 15 F-35Bs for the Italian Air Force.
- Italian Navy – 2 had been delivered as of October 2020. 15 F-35Bs planned for the Italian Navy.
- Japan Air Self-Defense Force – 13 F-35As operational as of April 2019 with a total order of 147, including 42 F-35Bs.
- Royal Norwegian Air Force – 25 F-35As delivered and operational, of which seven are based in the US for training in May 2020 of 52 F-35As planned in total.
- Republic of Korea Air Force – 11 F-35A delivered as of April 2020, out of 60 ordered.
- Republic of Korea Navy – about 20 F-35Bs planned
- Turkish Air Force – Four F-35As delivered to Luke Air Force Base for training in July 2018. 30 were ordered, of up to 120 total planned. Future purchases have been banned by the U.S. with contracts canceled by early 2020.
- United Arab Emirates Air Force - Up to 50 F-35As planned. But on January 27, 2021, the Biden administration temporarily suspended the F-35 sales to the UAE. After pausing the bill to review the sale, the Biden administration confirmed to move forward with the deal on 13 April 2021.
- Royal Air Force and Royal Navy (joint operation) – 21 F-35Bs received, with 18 in the UK and the rest in the US, where they are used for testing and training. 42 (24 FOC fighters and 18 training aircraft) to be fast-tracked by 2023; A total of 48 up to 80 F-35Bs could be ordered as of 2021.
Accidents and notable incidents
On 23 June 2014, an F-35A's engine caught fire at Eglin AFB. The pilot escaped unharmed, while the aircraft sustained an estimated US$50 million in damage. The accident caused all flights to be halted on 3 July. The fleet returned to flight on 15 July with flight envelope restrictions. In June 2015, the USAF Air Education and Training Command (AETC) issued its official report, which blamed the failure on the third stage rotor of the engine's fan module, pieces of which cut through the fan case and upper fuselage. Pratt & Whitney applied an extended "rub-in" to increase the gap between the second stator and the third rotor integral arm seal, as well as design alterations to pre-trench the stator by early 2016.
The first crash occurred on 28 September 2018 involving a USMC F-35B near Marine Corps Air Station Beaufort, South Carolina; the pilot ejected safely. The cause of the crash was attributed to a faulty fuel tube; all F-35s were grounded on 11 October pending a fleet-wide inspection of the tubes. The next day, most USAF and USN F-35s returned to flight status following the inspection.
On 9 April 2019, a JASDF F-35A attached to Misawa Air Base disappeared from radar about 84 miles (135 km) east of the Aomori Prefecture during a training mission over the Pacific Ocean. The pilot, Major Akinori Hosomi, had radioed his intention to abort the drill before disappearing. The US and Japanese navies searched for the missing aircraft and pilot, finding debris on the water that confirmed its crash; Hosomi's remains were recovered in June. In response, Japan grounded its 12 F-35As. There was speculation that China or Russia might attempt to salvage it; the Japanese Defense Ministry announced there had been no "reported activities" from either country. The F-35 reportedly did not send a distress signal nor did the pilot attempt any recovery maneuvers as the aircraft descended at a rapid rate. The accident report attributed the cause to the pilot's spatial disorientation.
On 19 May 2020, a USAF F-35A from the 58th Fighter Squadron crashed while landing at Eglin AFB. The pilot ejected and was in stable condition. The accident was attributed to a combination of pilot error induced by fatigue, an issue with the design of the oxygen system and the more complex nature of the aircraft as well as a distraction from a malfunctioning head-mounted display and failure of the flight control system to respond to pilot inputs.
On 29 September 2020, a USMC F-35B fighter jet crashed in Imperial County, California, after colliding with a Marine Corps KC-130 during air-to-air refuelling. The F-35B pilot was injured in the ejection, and the KC-130 crash-landed gear up in a field.
Data from Lockheed Martin: F-35 specifications, Lockheed Martin: F-35 weaponry, Lockheed Martin: F-35 Program Status, F-35 Program brief, FY2019 Select Acquisition Report (SAR), Director of Operational Test & Evaluation
- Crew: 1
- Length: 51.4 ft (15.7 m)
- Wingspan: 35 ft (11 m)
- Height: 14.4 ft (4.4 m)
- Wing area: 460 sq ft (43 m2)
- Aspect ratio: 2.66
- Empty weight: 29,300 lb (13,290 kg)
- Gross weight: 49,540 lb (22,471 kg)
- Max takeoff weight: 70,000 lb (31,751 kg)
- Fuel capacity: 18,250 lb (8,278 kg) internal
- Powerplant: 1 × Pratt & Whitney F135-PW-100 afterburning turbofan, 28,000 lbf (120 kN) thrust dry, 43,000 lbf (190 kN) with afterburner
- Maximum speed: Mach 1.6 at altitude
- Range: 1,500 nmi (1,700 mi, 2,800 km)
- Combat range: 669 nmi (770 mi, 1,239 km) on internal fuel
- Service ceiling: 50,000 ft (15,000 m)
- g limits: +9.0
- Wing loading: 107.7 lb/sq ft (526 kg/m2) at gross weight
- Thrust/weight: 0.87 at gross weight (1.07 at loaded weight with 50% internal fuel)
- Guns: 1 × 25 mm (0.984 in) GAU-22/A 4-barrel rotary cannon, 180 rounds
- Hardpoints: 4 × internal stations, 6 × external stations on wings with a capacity of 5,700 pounds (2,600 kg) internal, 15,000 pounds (6,800 kg) external, 18,000 pounds (8,200 kg) total weapons payload,with provisions to carry combinations of:
- AN/APG-81 AESA radar
- AN/AAQ-40 E/O Targeting System (EOTS)
- AN/AAQ-37 Distributed Aperture System (DAS) missile warning system
- AN/ASQ-239 Barracuda electronic warfare system
- AN/ASQ-242 CNI suite, which includes
- Harris Corporation Multifunction Advanced Data Link (MADL) communication system
- Link 16 data link
- An IFF interrogator and transponder
- HAVE QUICK
- AM, VHF, UHF AM, and UHF FM Radio
- GUARD survival radio
- A radar altimeter
- An instrument landing system
- A TACAN system
- Instrument carrier landing system
- A JPALS
- TADIL-J JVMF/VMF
Differences between variants
|Length||51.4 ft (15.7 m)||51.2 ft (15.6 m)||51.5 ft (15.7 m)|
|Wingspan||35 ft (10.7 m)||35 ft (10.7 m)||43 ft (13.1 m)|
|Height||14.4 ft (4.39 m)||14.3 ft (4.36 m)||14.7 ft (4.48 m)|
|Wing Area||460 sq ft (42.74 m2)||460 sq ft (42.74 m2)||668 sq ft (62.06 m2)|
|Empty weight||28,999 lb (13,154 kg)||32,472 lb (14,729 kg)||34,581 lb (15,686 kg)|
|Internal fuel||18,250 lb (8,278 kg)||13,500 lb (6,123 kg)||19,750 lb (8,958 kg)|
|Weapons payload||18,000 lb (8,160 kg)||15,000 lb (6,800 kg)||18,000 lb (8,160 kg)|
|Max takeoff weight||70,000 lb (31,800 kg) class||60,000 lb (27,200 kg) class||70,000 lb (31,800 kg) class|
|Range||>1,200 nmi (2,200 km)||>900 nmi (1,700 km)||>1,200 nmi (2,200 km)|
|Combat radius on
|669 nmi (1,239 km)||505 nmi (935 km)||670 nmi (1,241 km)|
• full fuel:
• 50% fuel:
- Lockheed Martin X-35 – Concept demonstrator aircraft for Joint Strike Fighter program
Aircraft of comparable role, configuration, and era
- Chengdu J-20 – Chinese fifth-generation fighter aircraft
- KAI KF-21 Boramae – Advanced multirole fighter aircraft under development by South Korea and Indonesia
- TAI TF-X - Turkish fifth generation fighter under development by Turkish Aerospace Industries
- HAL AMCA - Indian fifth generation fighter under development by Hindustan Aeronautics Limited
- Lockheed Martin F-22 Raptor – American fifth-generation air superiority fighter
- Shenyang FC-31 – Fifth-generation jet fighter under development by Shenyang Aircraft Corporation
- Sukhoi Su-57 – Russian fifth-generation fighter aircraft
- List of fighter aircraft
- List of active United States military aircraft
- List of megaprojects, Aerospace
- By 2014, the program was "US$163 billion over budget [and] seven years behind schedule".
- Lockheed acquired General Dynamics fighter division at Fort Worth in 1993 and merged with Martin Marietta in 1995 to form Lockheed Martin.
- As these were concept demonstrator aircraft for risk reduction, they did not need to have the internal structure or most subsystems of the final aircraft as a weapon system.
- The F-35 swivel nozzle design was pioneered by the Convair Model 200.
- The thrust vectoring nozzle would eventually be replaced by an axisymmetric low-observable nozzle in order to reduce weight.
- FACO is also performed in Italy and Japan for some non-U.S. customers as part of the industrial benefits from international cooperation.
- This first prototype lacked the weight optimization from SWAT.
- Early F-35Bs have a service life as low as 2,100 hours before retrofits as seen on Lot 9 and later aircraft.
- Turkey was the sole supplier of several F-35 parts, thus forcing the program to find replacement vendors.
- The F-35C has additional ailerons at the folding sections of the wings.
- In 2014, Michael Gilmore, Director of Operational Test & Evaluation, stated that "software development, integration in the contractor labs, and delivery of mature capability to flight test continued to be behind schedule."
- Rockwell Collins and Elbit Systems formed the joint venture Vision Systems International (VSI), later renamed Collins Elbit Vision Systems (CEVS).
- In 2002, solid-state laser weapons were reportedly being developed for the F-35.
- "Bubbling and blistering" of the horizontal tails and tail booms were observed once during flutter tests of the F-35B and C in late 2011; according to the program office, the problem has only occurred once despite numerous attempts to replicate it, and an improved spray-on coating has been implemented since as a mitigation measure. On 17 December 2019, the Pentagon program office closed the issue with no further actions planned, and instead is imposing a time limit on high-speed flight for the F-35B and C in order to reduce the risk of damaging the stealth coatings and antennas located on the back of the aircraft.
- Wing drop is an uncommanded roll that can occur during high-g transsonic maneuvering.
- F-35B and F-35C have the cannon in an external pod with 220 rounds.
- Drew, James (31 July 2015). "First operational F-35 squadron declared ready for combat". FlightGlobal.
- Insinna, Valerie (2 August 2016). "Air Force Declares F-35A Ready for Combat". Defense News.
- Eckstein, Megan (28 February 2019). "Navy Declares Initial Operational Capability for F-35C Joint Strike Fighter". USNI News.
- "F-35 Lightning II Program Status and Fast Facts" (PDF). F35.com. Lockheed Martin. April 2021. Retrieved 8 April 2021.
- "F-35 Global Partnerships". Lockheed Martin. Archived from the original on 2 September 2012. Retrieved 31 October 2012.
- Dudley, Richard (5 March 2012). "Program Partners Confirm Support for F-35 Joint Strike Fighter". Defence Update.
- Pawlyk, Oriana (28 December 2020). "Key US Ally Declares Its F-35s Ready for Combat". Military.com. 10th paragraph. Retrieved 29 December 2020.
- Drusch, Andrea (16 February 2014). "Fighter plane cost overruns detailed". Politico. Retrieved 29 September 2015.
- Miller, Kathleen; Capaccio, Tony & Ivory, Danielle (22 February 2013). "Flawed F-35 Too Big to Kill as Lockheed Hooks 45 States". Bloomberg.com.
- Ciralsky, Adam (16 September 2013). "Will the F-35, the U.S. Military's Flaw-Filled, Years-Overdue Joint Strike Fighter, Ever Actually Fly?". Vanity Fair. Retrieved 29 September 2015.
- Ahronheim, Anna (22 May 2018). "IAF Commander: Israel First To Use F-35 Jet In Combat". The Jerusalem Post.
- "Select Acquisition Report: F-35 Lightning II Joint Strike Fighter (JSF) Program (F-35) as of FY 2020 President's Budget" (PDF). Washington Headquarters Services. 17 April 2019. Archived from the original (PDF) on 6 June 2020. Retrieved 5 February 2020.
- Drew, James (25 March 2016). "Lockheed F-35 service life extended to 2070". FlightGlobal.
- Rich, Stadler (October 1994). "Common Lightweight Fighter" (PDF). Code One Magazine. Lockheed.
- "History (Pre-JAST)". Joint Strike Fighter. Archived from the original on 6 December 2019. Retrieved 24 January 2020.
- "History (JAST)". Joint Strike Fighter. Archived from the original on 15 July 2019. Retrieved 24 January 2020.
- Barrie, Douglas; Norris, Guy & Warwick, Graham (4 April 1995). "Short take-off, low funding". FlightGlobal. Archived from the original on 17 July 2015. Retrieved 24 January 2020.
- "The JSF UK Industry Team". Martin Baker Aircraft Company Limited. Archived from the original on 27 April 2006.
- "US, UK sign JAST agreement". Aerospace Daily. New York: McGraw-Hill. 25 November 1995. p. 451.
- Renshaw, Kevin (12 August 2014). "F-35B Lightning II Three-Bearing Swivel Nozzle". Code One Magazine.
- Wilson, George C. (22 January 2002). "The engine that could". Government Executive. Archived from the original on 19 October 2013.
- "Propulsion system for a vertical and short takeoff and landing aircraft, United States Patent 5209428". PatentGenius.com. 7 May 1990. Archived from the original on 25 February 2012.
- Gunston, Bill (1997). Yakovlev Aircraft since 1924. London: Putnam Aeronautical Books. p. 16. ISBN 1-55750-978-6.
- Sheridan, Arthur E.; Burnes, Robert (13 August 2019). "F-35 Program History: From JAST to IOC". American Institute of Aeronautics and Astronautics (AIAA): 50. doi:10.2514/5.9781624105678.0001.0076. ISBN 978-1-62410-566-1.
- Bevilaqua, Paul M. (September 2005). "Joint Strike Fighter Dual-Cycle Propulsion System". Journal of Propulsion and Power. 21 (5): 778–783. doi:10.2514/1.15228.
- "History (JSF)". Joint Strike Fighter. Archived from the original on 15 July 2019. Retrieved 24 January 2020.
- Schreiber, Liev (3 February 2003). "Battle of the X-Planes". NOVA. PBS. Archived from the original on 29 June 2019. Battle of the X-Planes. Retrieved 25 January 2020.
- "History (F-35 Acquisition)". Joint Strike Fighter. Archived from the original on 6 July 2019. Retrieved 23 January 2021.
- Parsch, Andreas (27 April 2006). "Non-Standard DOD Aircraft Designations". Designation Systems.
- Keijsper 2007, pp. 122, 124.
- Hehs, Eric (15 May 2008). "X to F: F-35 Lightning II And Its X-35 Predecessors". Code One Magazine. Lockheed Martin.
- Keijsper 2007, p. 119
- Fulghum, David A.; Wall, Robert (19 September 2004). "USAF Plans for Fighters Change". Aviation Week & Space Technology.
- Keijsper 2007, p. 124,
- Pappalardo, Joe (November 2006). "Weight Watchers: How a team of engineers and a crash diet saved the Joint Strike Fighter". Air & Space Magazine. Archived from the original on 24 May 2014.
- Knotts, Keith P. (9 July 2013). "CF-35 Lightning II: Canada's Next Generation Fighter" (PDF). Westdef.com. Archived from the original (PDF) on 21 February 2014.
- "'Lightning II' moniker given to Joint Strike Fighter". U.S. Air Force. 7 June 2006.
- "F-35 Software Development". Lockheed Martin. Archived from the original on 2 July 2020. Retrieved 2 February 2020.
- "GAO-06-356: DOD Plans to Enter Production before Testing Demonstrates Acceptable Performance" (PDF). Government Accountability Office. March 2006. Archived from the original (PDF) on 1 August 2020. Retrieved 4 December 2011.
- Insinna, Valerie (28 April 2018). "F-35 program office wraps up final developmental flight test". Defense News.
- Haynes, Deborah (15 June 2019). "F-35 jets: Chinese-owned company making parts for top-secret UK-US fighters". Sky News.
- Doffman, Zak (15 June 2019). "U.S. and U.K. F-35 Jets Include 'Core' Circuit Boards From Chinese-Owned Company". Forbes.
- Minnick, Wendell (24 March 2016). "Chinese Businessman Pleads Guilty of Spying on F-35 and F-22". Defense News. Retrieved 9 April 2019.
- Cox, Bob (1 March 2010). "Internal Pentagon memo predicts that F-35 testing won't be complete until 2016". Fort Worth Star-Telegram.
- Capaccio, Tony (6 January 2010). "Lockheed F-35 Purchases Delayed in Pentagon's Fiscal 2011 Plan". Bloomberg BusinessWeek. Archived from the original on 10 January 2010.
- Charette, Robert (12 September 2012). "F-35 Program Continues to Struggle with Software". IEEE Spectrum.
- "FY18 DOD Programs F-35 Joint Strike Fighter (JSF)" (PDF). Director, Operational Test and Evaluation. 2018. p. 25. Archived from the original (PDF) on 26 June 2019.
- "Is the F-35 worth it?". 60 Minutes. 16 February 2014. CBS News.
- Tirpak, John (14 March 2016). "All For One and One for All". Air Force.
- Shalal, Andrea (27 April 2015). "U.S. watchdog finds quality violations in Pratt work on F-35 engine". Reuters.
- Barrett, Paul (10 April 2017). "Danger Zone". Bloomberg Businessweek. pp. 50–55.
- Schneider, Greg (27 October 2001). "Lockheed Martin Beats Boeing for Fighter Contract". The Washington Post.
- Dao, James (27 October 2001). "Lockheed Wins $200 Billion Deal for Fighter Jet". The New York Times.
- Merle, Renae (15 March 2005). "GAO Questions Cost Of Joint Strike Fighter". The Washington Post.
- Shalal-Esa, Andrea (17 September 2012). "Pentagon tells Lockheed to shape up on F-35 fighter". Reuters.
- Tirpak, John A. (8 January 2014). "The Cost of Teamwork". Air Force. Arlington, Virginia: Air Force Association. Archived from the original on 25 May 2014. Retrieved 12 January 2014.
- Capaccio, Anthony (10 July 2017). "F-35 Program Costs Jump to $406.5 Billion in Latest Estimate". Bloomberg.
- Astore, William J. (16 September 2019). "The Pentagon's $1.5 Trillion Addiction to the F-35 Fighter". The Nation.
- Tirpak, John (29 October 2019). "Massive $34 Billion F-35 Contract Includes Price Drop as Readiness Improves". Air Force.
- "F-35 Joint Strike Fighter Development Is Nearly Complete, but Deficiencies Found in Testing Need to Be Resolved" (PDF). GAO. June 2018. Retrieved 12 June 2019.
- Insinna, Valerie (18 October 2019). "The F-35 jet might hit full-rate production more than a year late". Defense News.
- Insinna, Valerie (6 December 2019). "After a couple months delay, the F-35 moves into operational tests". Defense News.
- Tirpak, John (25 February 2019). "Keeping the F-35 Ahead of the Bad Guys". Air Force.
- "Lockheed Martin Awarded $1.8 Billion for F-35 Block 4 Development". Defense World. 8 June 2019.
- Zazulia, Nick (19 March 2019). "U.S. Defense Department Plans to Spend $6.6B on F-35 Continuing Development Through 2024". Avionics International.
- Trimble, Steven (9 July 2018). "USAF starts work on defining adaptive engine for future fighter". Flight Global.
- Warwick, Graham (12 September 2013). "Northrop Develops Laser Missile Jammer For F-35". Aviation Week. Archived from the original on 20 April 2014. Retrieved 2 February 2020.
- "F-35 Joint Strike Fighter (JSF) Lightning II – International Partners". Global Security. Retrieved 7 April 2010.
- "Estimated JSF Air Vehicle Procurement Quantities" (PDF). Joint Strike Fighter. April 2010. Archived from the original (PDF) on 27 June 2011.
- "F-35 Lightning: The Joint Strike Fighter Program, 2012". Defense Industry Daily. 30 October 2012. Archived from the original on 25 January 2013.
- Schnasi, Katherine V. (May 2004). "Joint Strike Fighter Acquisition: Observations on the Supplier Base" (PDF). US General Accounting Office. Archived from the original (PDF) on 16 August 2020. Retrieved 8 February 2006.
- "Industry Canada F-35 Joint Strike Fighter (JSF) Canada's Next Generation Fighter Capability". Government of Canada. Archived from the original on 22 September 2010. Retrieved 25 November 2010.
- Combat Aircraft Monthly, September 2010, p. 24.
- Winters, Vice Adm. Mat (9 December 2018). "Head of F-35 Joint Program Office: Stealth fighter enters the new year in midst of a growing phase". Defense News. Retrieved 5 February 2020.
- Manson, Katrina; Pitel, Laura (19 June 2018). "US Senate blocks F-35 sales to Turkey". Financial Times. Retrieved 19 June 2018.
- Liptak, Kevin; Gaouette, Nicole (17 July 2019). "Trump blames Obama as he reluctantly bans F-35 sales to Turkey". CNN. Retrieved 17 July 2019.
- Host, Pat (1 October 2018). "F-35 chief reaffirms Turkey's status as committed programme partner". Jane's 360. Archived from the original on 3 October 2018.
- "US Lockheed Martin F-35 chosen as Japan fighter jet". BBC News. 20 December 2011.
- Vasarri, Chiara (15 February 2012). "Italy to Cut F-35 Fighter Jet Orders as Part of Defense Revamp". Bloomberg BusinessWeek. Archived from the original on 18 January 2013.
- "Amberley welcomes full RAAF Growler fleet". Australian Aviation. 7 July 2017. Archived from the original on 17 October 2017. Retrieved 17 October 2017.
- "A timeline on Canada's involvement in the F-35 program". Canada.com. 5 April 2012. Archived from the original on 10 April 2012.
- Drew, James (21 October 2015). "Canadian F-35 exit could signal wider air force review". FlightGlobal.
- Mahmud, Aqil Haziq (18 January 2019). "Singapore identifies F-35 fighter jet to replace F-16s, expects to buy 'small number' for full testing". Channel NewsAsia. Retrieved 18 January 2019.
- "Poland plans to buy 32 F-35A fighters: minister". Reuters. 28 May 2019.
- Adamowski, Jaroslaw (31 January 2020). "Poland inks $4.6 billion contract for F-35 fighter jets". Defense News.
- "Capabilities: F-35 Lightning II". Lockheed Martin. Archived from the original on 24 July 2010.
- Kent, John R.; Geisel, Chris (16 November 2010). "F-35 STOVL supersonic". Lockheed Martin.
- "Open System Architecture (OSA) Secure Processing" (PDF). L3 Technologies. March 2011. Archived from the original (PDF) on 4 November 2016.
- Adams, Charlotte (1 September 2003). "JSF: Integrated Avionics Par Excellence". Aviation Today.
- Amaani, USAF Tech. Sgt. Lyle (3 April 2009). "Air Force takes combat air acquisitions priorities to Hill". U.S. Air Force.
- Ryberg, Eric S. (26 February 2002). "The Influence of Ship Configuration on the Design of the Joint Strike Fighter" (PDF). Naval Surface Warfare Center Dahlgren Division. p. 5.
- Whittle, Richard (February 2012). "The Ultimate Fighter?". Air & Space. Archived from the original on 16 January 2013. Retrieved 24 February 2013.
- Hehs, Eric (15 July 2000). "JSF Diverterless Supersonic Inlet". Code One Magazine. Retrieved 28 December 2012.
- Sloan, Jeff (19 October 2009). "Skinning the F-35 fighter". Composites World. Retrieved 24 November 2016.
- "Contract Awarded To Validate Process For JSF". Aerospace Manufacturing and Design. 17 May 2010. Archived from the original on 14 March 2012.
- Trimble, Stephen (26 May 2011). "Lockheed Martin reveals F-35 to feature nanocomposite structures". Flight International. Archived from the original on 30 May 2011.
- Nativi, Andy (5 March 2009). "F-35 Air Combat Skills Analyzed". Aviation Week. Archived from the original on 26 December 2010.
- Crébas, Frank (May 2018). "F-35 – Out of the Shadows". Combat Aircraft Monthly. Vol. 19 no. 5. Key Publishing. Retrieved 8 February 2020.
- "Flying The F-35: An Interview With Jon Beesley, F-35 Chief Test Pilot". Lockheed Martin. Archived from the original on 18 December 2014. Retrieved 25 November 2010.
- Seligman, Lara (1 March 2016). "Norwegian F-35 Pilot Counters Controversial Dogfighting Report". Defense News.
- "F-35 Lightning II Program Status and Fast Facts" (PDF). F-35.ca. Lockheed Martin. 13 March 2012. Archived from the original (PDF) on 24 May 2013.
- George, Eric (1 May 2010). "F-35 avionics: an interview with the Joint Strike Fighter's director of mission systems and software". Military & Aerospace Electronics (Interview). 21 (5). PennWell Corporation. Archived from the original on 1 January 2016.
- Sherman, Ron (1 July 2006). "F-35 Electronic Warfare Suite: More Than Self-Protection". Aviation Today.
- "Hey C and C++ Can Be Used In Safety Critical Applications Too!". Journal of Cyber Security and Information Systems. 11 February 2001.
- Warwick, Graham (7 June 2010). "Flight Tests Of Next F-35 Mission-System Block Underway". Aviation Week.
- "Raytheon Selects RACE++ Multicomputers for F-35 Joint Strike Fighter". EmbeddedStar.com. Archived from the original on 27 October 2015. Retrieved 25 October 2015.
- McHale, John (1 February 2010). "F-35 Joint Strike Fighter leverages COTS for avionics systems". Military & Aerospace Electronics. PennWell Corporation. Archived from the original on 21 September 2013.
- Philips, E. H. (5 February 2007). "The Electric Jet". Aviation Week & Space Technology.
- Parker, Ian (1 June 2007). "Reducing Risk on the Joint Strike Fighter". Aviation Today.
- "Tens of thousands of Xilinx FPGAs to be supplied by Lockheed Martin for F-35 Joint Strike Fighter avionics". Intelligent Aerospace. 16 June 2013. Archived from the original on 12 January 2014. Retrieved 16 June 2013.
- FY2013 DOD PROGRAMS F-35 Joint Strike Fighter (JSF)
- Reed, John (23 November 2010). "Schwartz Concerned About F-35A Delays". DoD Buzz. Archived from the original on 26 November 2010.
- Lyle, Amaani (6 March 2014). "Program executive officer describes F-35 progress". U.S Air Force.
- "APG-81 (F-35 Lightning II)". Northrop Grumman Electronic Systems. Archived from the original on 23 January 2013. Retrieved 4 August 2007.
- "F-35 Distributed Aperture System (EO DAS)". Northrop Grumman. Archived from the original on 2 April 2010. Retrieved 6 April 2010.
- Lemons, Greg; Carrington, Karen; Frey, Dr. Thomas; Ledyard, John (24 June 2018). "F-35 Mission Systems Design, Development, and Verification" (PDF). American Institute of Aeronautics and Astronautics. doi:10.2514/6.2018-3519. ISBN 978-1-62410-556-2. Retrieved 1 February 2020.
- "Lockheed Martin Missiles and Fire Control: Joint Strike Fighter Electro-Optical Targeting System". Lockheed Martin. Archived from the original on 6 January 2009. Retrieved 11 April 2008.
- "ASQ242 Datasheet" (PDF). Northrop Grumman.
- "F-35 jet fighters to take integrated avionics to a whole new level". Military & Aerospace Electronics. PennWell Corporation. 1 May 2003.
- "Israel, US Negotiate $450 Million F-35I Avionic Enhancements". Defense Update. 27 July 2012. Archived from the original on 30 July 2012.
- Donald, David (17 June 2019). "F-35 Looks to the Future". Aviation International News. Retrieved 1 February 2020.
- "Lockheed reveals Advanced EOTS targeting sensor for F-35 Block 4". Flight Global. 10 September 2015.
- Abbott, Rich (18 June 2018). "Raytheon Picked to Produce F-35 Sensor". Avionics International.
- Clark, Colin (15 December 2014). "Pawlikowski On Air Force Offset Strategy: F-35s Flying Drone Fleets". Breaking Defense.
- "Fast History: Lockheed's Diverterless Supersonic Inlet Testbed F-16". Aviation Intel. 22 October 2012. Archived from the original on 7 September 2013.
- "F-35 Joint Strike Fighter (JSF) Lightning II". Global Security. Retrieved 16 November 2010.
- Tirpak, John A. (26 November 2014). "The F-35 on Final Approach". Air Force. Retrieved 1 February 2020.
- Clark, Colin (11 March 2015). "Threat Data Biggest Worry For F-35A's IOC; But It 'Will Be On Time'". Breaking Defense. Retrieved 31 March 2015.
- Clark, Colin (6 June 2014). "Gen. Mike Hostage On The F-35; No Growlers Needed When War Starts". Breaking Defense.
- Butler, Amy (17 May 2010). "New, Classified Stealth Concept Could Affect JSF Maintenance Costs". Aviation Week.
- "USAF FY00 activity on the JSF". Director, Operational Test & Evaluation. Archived from the original on 23 July 2011.
- "Request for Binding Information Response to the Royal Norwegian Ministry of Defence" (PDF). Lockheed Martin. April 2008. Archived from the original (PDF) on 12 October 2012 – via Government.no.
- Capaccio, Tony (4 May 2011). "Lockheed Martin's F-35 Fighter Jet Passes Initial Stealth Hurdle". Bloomberg News.
- "F-35 – Beyond Stealth". Defense Update. 14 June 2015. Retrieved 5 April 2019.
- Ralston, James; Heagy, James; Sullivan, Roger (September 1998). "Environmental/Noise Effects on UHF/VHF UWB SAR" (PDF). Defense Technical Information Center. Retrieved 2 January 2015.
- Plopsky, Guy; Bozzato, Fabrizio (21 August 2014). "The F-35 vs. The VHF Threat". The Diplomat.
- Brewer, Jeffrey; Meadows, Shawn (Summer 2006). "Survivability of the Next Strike Fighter". Aircraft Survivability: Susceptibility Reduction. Joint Aircraft Survivability Program Office. p. 23 – via Defense Technical Information Center.
- Lockie, Alex (5 May 2017). "This strange mod to the F-35 kills its stealth near Russian defenses – and there's good reason for that". Business Insider.
- Alaimo, Carol Ann (30 November 2008). "Noisy F-35 Still Without A Home". Arizona Daily Star.
- "Report on Jet Engine Noise Reduction" (PDF). Naval Research Advisory Committee. April 2009.
- "F-35 Acoustics Based on Edwards AFB Acoustics, Test". JSF Program Office & Lockheed Martin. April 2009.
- "F-35, F-16 noise difference small, Netherlands study shows". Aviation Week. 31 May 2016.
- Ledbetter, Stewart (31 May 2019). "Wonder no more: F-35 jet noise levels finally confirmed at BTV". NBC News.
- Hensley, Senior Airman James (19 May 2015). "F-35 pilot training begins at Luke". 56th Fighter Wing Public Affairs. Retrieved 30 January 2020.
- Schutte, John (10 October 2007). "Researchers fine-tune F-35 pilot-aircraft speech system". U.S. Air Force. Archived from the original on 23 April 2016.
- "VSI's Helmet Mounted Display System flies on Joint Strike Fighter". Rockwell Collins. 2007. Archived from the original on 17 July 2011.
- "Martin-Baker". The JSF UK Industry Team. Archived from the original on 21 October 2008. Retrieved 23 November 2009.
- Lowell, Capt. Jonathan (25 August 2019). "Keeping cool over Salt Lake". U.S. Air Force. Retrieved 30 January 2020.
- Zazulia, Nick (24 August 2018). "F-35: Under the Helmet of the World's Most Advanced Fighter". Avionics International.
- Davis, Brigadier General Charles R. (26 September 2006). "F-35 Program Brief" (PDF). U.S. Air Force. Archived from the original (PDF) on 25 July 2020 – via Joint Strike Fighter.
- F35 JSF Videos. "F-35 Distributed Aperture System EO DAS". YouTube. Retrieved 23 November 2009.
- Davenport, Christian. "Meet the most fascinating part of the F-35: The $400,000 helmet". The Washington Post. Retrieved 2 August 2015.
- Seligman, Lara (14 October 2015). "F-35's Heavier Helmet Complicates Ejection Risks". Defense News. TEGNA.
- "Lockheed Martin Awards F-35 Contract". Zack's Investment Research. 17 November 2011. Archived from the original on 30 April 2012.
- Warwick, Graham (21 April 2011). "Lockheed Weighs Alternate F-35 Helmet Display". Aviation Week.
- Carey, Bill (15 February 2012). "BAE Drives Dual Approach To Fixing F-35 Helmet Display Issues". Aviation International News.
- "Lockheed Martin Selects BAE Systems to Supply F-35 Joint Strike Fighter (JSF) Helmet Display Solution". BAE Systems. 10 October 2011. Archived from the original on 28 January 2013.
- Majumdar, Dave (10 October 2013). "F-35 JPO drops development of BAE alternative helmet". Flight Global. Archived from the original on 29 April 2014.
- "Lockheed Cites Good Reports on Night Flights of F-35 Helmet". Reuters. 30 October 2012. Archived from the original on 24 September 2015. Retrieved 1 July 2017.
- "Small Diameter Bomb II – GBU-53/B". Defense Update. Archived from the original on 27 February 2015. Retrieved 28 August 2010.
- "F-35B STOVL Variant". Lockheed Martin. Archived from the original on 23 February 2009. Retrieved 25 November 2010.
- "Spear Capability 3". MBDA Systems. 9 June 2019.
This new, F-35 Lightning II internal bay compatible, air-to-surface missile
- Keller, John (17 August 2018). "Navy asks BAE Systems to build T-1687/ALE-70(V) electronic warfare (EW) towed decoys for F-35". Military Aerospace Electronics.
- Keijsper 2007, pp. 220, 239.
- Hewson, Robert (4 March 2008). "UK changes JSF configuration for ASRAAM". Jane's. Archived from the original on 16 September 2012.
- Tran, Pierre (22 February 2008). "MBDA Shows Off ASRAAM". Defense News.
- "JSF Suite: BRU-67, BRU-68, LAU-147 – Carriage Systems: Pneumatic Actuated, Single Carriage". ITT.com. 2009.
- Digger, Davis (30 October 2007). "JSF Range & Airspace Requirements" (PDF). Headquarters Air Combat Command. Archived from the original (PDF) on 19 December 2008 – via Defense Technical Information Center.
- "F-35 gun system". General Dynamics Armament and Technical Products. Archived from the original on 6 June 2011."GAU-22/A" (PDF). General Dynamics Armament and Technical Products. Archived from the original (PDF) on 17 July 2011. Retrieved 7 April 2011.
- Keijsper 2007, p. 233.
- Donald, David (11 July 2012). "Terma Highlights F-35 Multi-Mission Pod". Aviation International News.
- Bolsøy, Bjørnar (17 September 2009). "F-35 Lightning II status and future prospects". F-16.net. Retrieved 23 November 2009.
- Everstine, Brian W. (17 June 2019). "Lockheed Looking at Extending the F-35's Range, Weapons Suite". Air Force Mag. Retrieved 31 January 2020.
- Lake 2010, pp. 37–45.
- Trimble, Stephen (17 September 2010). "MBDA reveals clipped-fin Meteor for F-35". Flight International. Archived from the original on 21 September 2010.
- "F-35B Internal Weapons Bay Can't Fit Required Load of Small Diameter Bomb IIs". Inside Defense.com. 25 February 2015.
- "Air Force President's Budget FY20". Assistant Secretary of the Air Force, Financial Management and Comptroller.
- "Important cooperative agreement with Lockheed Martin". Kongsberg Defence & Aerospace. 9 June 2009. Archived from the original on 16 April 2012.
- Tirpak, John A. (17 March 2014). "Nuclear Lightning". Air Force. Arlington, VA: Air Force Association. Archived from the original on 25 May 2014.
- Fulghum, David A. (8 July 2002). "Lasers being developed for F-35 and AC-130". Aviation Week and Space Technology. Archived from the original on 26 June 2004.
- Morris, Jefferson (26 September 2002). "Keeping cool a big challenge for JSF laser, Lockheed Martin says". Aerospace Daily. Archived from the original on 4 June 2004.
- Fulghum, David A. (22 July 2002). "Lasers, HPM weapons near operational status". Aviation Week and Space Technology. Archived from the original on 13 June 2004.
- Norris, Guy (20 May 2013). "High-Speed Strike Weapon To Build On X-51 Flight". Aviation Week. Archived from the original on 20 May 2013.
- Drew, James (5 October 2015). "Lockheed considering laser weapon concepts for F-35". Flight Global.
- Parsons, Dan (15 February 2015). "USAF chief keeps sights on close air support mission". Flight Global.
- "Long Road Ahead For Possible A-10 Follow-On". Aviation Week. 24 March 2015.
- "Frequently Asked Questions about JSF". Joint Strike Fighter. Archived from the original on 1 August 2010. Retrieved 6 April 2010.
- Warwick, Graham (17 March 2011). "Screech, the F135 and the JSF Engine War". Aviation Week. Archived from the original on 21 March 2010.
- Katz, Dan (7 July 2017). "The Physics And Techniques Of Infrared Stealth". Aviation Week. Retrieved 12 April 2019.
- Majumdar, Dave (1 October 2012). "US Navy works through F-35C air-ship integration issues". Flight Global. Retrieved 1 February 2020.
- "Custom tool to save weeks in F-35B test and evaluation". Naval Air Systems Command. 6 May 2011 – via Defense Aerospace.com.
- Zolfagharifard, Ellie (28 March 2011). "Rolls-Royce's LiftSystem for the Joint Strike Fighter". The Engineer.
- "LiftSystem". Rolls-Royce. Retrieved 23 November 2009.
- "Swivel nozzle VJ101D and VJ101E". Vertical Flight Society. 20 June 2009.
- Hirschberg, Mike (1 November 2000). "V/STOL Fighter Programs in Germany: 1956–1975" (PDF). International Powered Lift Conference. p. 50. Retrieved 3 October 2012 – via robertcmason.com.
- "How the Harrier hovers". Harrier.org. Archived from the original on 7 July 2010. Retrieved 16 November 2010.
- Kjelgaard, Chris (21 December 2007). "From Supersonic to Hover: How the F-35 Flies". Space.
- Hutchinson, John. "Going Vertical: Developing a STOVL system" (PDF). Ingenia.org.uk. Archived from the original (PDF) on 20 July 2015. Retrieved 23 November 2009.
- "GE Rolls-Royce Fighter Engine Team completes study for Netherlands". Rolls-Royce plc. 16 June 2009. Retrieved 23 November 2009.
- Trimble, Stephen (11 June 2009). "Rolls-Royce: F136 survival is key for major F-35 engine upgrade". Flight International. Archived from the original on 14 June 2009.
- Majumdar, Dave (2 December 2011). "GE, Rolls Royce Stop Funding F-35 Alt Engine". Defense News. Archived from the original on 29 July 2012.
- "Pratt & Whitney Validates Growth Option for F135 Engine". PRNewswire.com. 31 May 2017. Retrieved 25 November 2017.
- Kjelgaard, Chris (15 June 2017). "P&W Outlines Three-step F135 Development Pathway". Aviation International News. Retrieved 11 January 2020.
- Kjelgaard, Chris (13 June 2018). "P&W Outlines New Plan for F-35 Engine Upgrades". Aviation International News. Retrieved 11 January 2020.
- Norris, Guy; Anselmo, Joe (21 July 2018). "F-35 Engine Upgrade Would Enable Directed Energy Weapons". Aviation Week. Retrieved 11 January 2020.
- Zazulia, Nick (11 October 2018). "Rejuvenating the Raptor: Roadmap for F-22 Modernization". Avionics Today. Archived from the original on 16 February 2019. Retrieved 15 February 2019.
- Majumdar, Dave (6 November 2012). "US Air Force praises early performance of Lockheed Martin F-35". Flight Global.
- Edwards, Jack E. (16 December 2010). "Defense Management: DOD Needs to Monitor and Assess Corrective Actions Resulting from Its Corrosion Study of the F-35 Joint Strike Fighter" (PDF). Government Accountability Office. Archived from the original (PDF) on 5 August 2020. Retrieved 17 December 2010.
- Trimble, Stephen (12 July 2010). "Farnborough: Lockheed encouraged by pace of F-35 testing". Flight International.
- "Li-Ion Battery in Production for F-35s". Avionics International. 23 July 2013. Archived from the original on 25 January 2020. Retrieved 25 January 2020.
- Hawkins, Dan (27 July 2012). "F-35 maintenance training spawns USMC's first air FTD". Global Security.
- "F-35, Maintenance and the Challenge of Service Standardization". Second Line of Defense. 9 June 2011. Archived from the original on 4 July 2011.
- Majumdar, Dave (20 November 2012). "USMC finds workaround for cyber vulnerability on F-35 logistics system". Flight International.
- Tucker, Patrick (8 January 2015). "The F-35 Has To Phone Texas Before Taking Off". Defense One.
- Host, Pat (22 January 2020). "Pentagon announces replacement for F-35's ALIS". Jane's Defence Weekly.
- "Mighty F-35 Lightning II Engine Roars to Life". Lockheed Martin. 20 September 2006.
- Department of Defense Authorization for Appropriations for Fiscal Year 2011 (Report).
- Wolf, Jim (18 March 2010). "F-35 fighter makes first vertical landing". Reuters.
- Hudson, Mary L.; Glass, Michael L.; Tucker, Lt Col Tucker; Somers, C. Eric; Caldwell, Robert C. (24 June 2018). "F-35 System Development and Demonstration Flight Testing at Edwards Air Force Base and Naval Air Station Patuxent River". American Institute of Aeronautics and Astronautics (AIAA): 27. doi:10.2514/6.2018-3371. ISBN 978-1-62410-556-2.
- Branch, Army Sgt Ricardo (8 March 2012). "Northern Edge fields new radar system". Northern Edge Joint Information Bureau. Archived from the original on 27 October 2013.
- Saiki, Lt. Col. Tracey (28 June 2011). "Continued testing of F-35 JSF sensors a success at Northern Edge 2011". U.S. Air Force. Retrieved 18 April 2012.
- Majumdar, Dave (17 January 2012). "F-35C Tailhook Design Blamed for Landing Issues". Defense News. Archived from the original on 2 January 2013.
- Majumdar, Dave (12 December 2013). "Lockheed: New Carrier Hook for F-35". U.S. Naval Institute. Retrieved 12 December 2013.
- Sweetman, Bill (June 2009). "Get out and fly". Defense Technology International. pp. 43–44. Archived from the original on 18 August 2009.
- Trimble, Stephen (22 November 2010). "Fatigue cracks raise questions about key decision in F-35 redesign". Flight Global.
- Insinna, Valerie & Larter, David (12 June 2019). "Supersonic speeds could cause big problems for the F-35's stealth coatings". Defense News.
- Larter, David B.; Insinna, Valerie & Mehta, Aaron (24 April 2020). "The Pentagon will have to live with limits on F-35's supersonic flights". Defense News. Retrieved 25 April 2020.
- "FY2019 DOT&E Report – F-35 Joint Strike Fighter Aircraft (F-35)" (PDF). dote.osd.mil. 2020.
- Capaccio, Tony (21 February 2014). "Lockheed F-35 for Marines Delayed as Test Exposes Cracks". Bloomberg.
- F-35A High Angle of Attack Operational Maneuvers. Lockheed Martin (Report). 14 January 2015.
- Clark, Colin (19 July 2017). "Pilots Say F-35 Superior Within Visual Range: Dogfight Criticisms Laid To Rest". Breaking Defense.
- "F-35B completes first sea trials on USS Wasp". Naval Air Systems Command. 24 October 2011. Retrieved 17 July 2012.
- "U.S. Marines see progress in F-35 testing despite challenges". Reuters. 29 August 2013. Archived from the original on 15 October 2015. Retrieved 1 July 2017.
- "F-35B Pilots Conduct Night Shipboard Landing Without Night-Vision". Inside the Navy. Inside Washington Publishers. 9 February 2013. Archived from the original on 15 September 2020. Retrieved 19 September 2013.
- "F-35B Complete At-Sea Developmental Testing". Naval Aviation News. 14 March 2017.
- "Navy jets trial new 'rolling' landing". BBC News. 15 October 2018. Retrieved 12 August 2019.
- "F-35C Completes First Night Flight Aboard Aircraft Carrier". U.S. Navy. 13 November 2014.
- Cavas, Christopher (17 August 2016). "F-35C Back at Sea for 3rd Round of Carrier Tests". Defense News.
- Grady, John (11 October 2018). "Preliminary F-35C Feedback is Positive, As Formal Operational Testing Begins This Fall". USNI News.
- Capaccio, Anthony (23 October 2017). "F-35s Hobbled by Parts Shortages, Slow Repairs, Audit Finds". Bloomberg.
- "The Hidden Troubles of the F-35". Defense News.
- Insinna, Valerie (24 April 2020). "The Pentagon has cut the number of serious F-35 technical flaws in half". Defense News.
- "F-35 Finally Can Use All Its Weapons In Combat". Aviation Week. 5 March 2018.
- Shalal-Esa, Andrea (27 February 2012). "USMC Near Start of F-35 Training Flights". Reuters.
- "Air Force issues flight release for Eglin AFB F-35A". U.S. Air Force. 28 February 2012. Archived from the original on 2 August 2013.
- Capaccio, Tony (28 September 2012). "Air Force Expands F-35 Trials Over Tester's Objections". Bloomberg BusinessWeek. Archived from the original on 18 January 2013.
- Clark, Colin (28 August 2012). "Pentagon's Testing Czar Questions F-35 Program's OTE Plan". Breaking Defense. Archived from the original on 31 August 2012.
- Shalal-Esa, Andrea (10 September 2012). "More problems raised at Pentagon F-35 fighter review". Reuters.
- Majumdar, Dave (7 September 2012). "USAF to start F-35 operational utility evaluation on 10 September". Flight International.
- Majumdar, Dave (16 November 2012). "USAF unit completes F-35 OUE activity". Flight Global. Archived from the original on 25 May 2014.
- Majumdar, Dave (17 November 2012). "MCAS Yuma receives(sic) first operational F-35B". Flight International.
- Majumdar, Dave (21 November 2012). "Simulation plays vital role in building F-35 tactics and aircraft development". Flight International.
- Everstine, Brian (17 December 2012). "F-35 pilot training starts next month at Eglin". Military Times. Archived from the original on 10 March 2013.
- Cenciotti, David (9 January 2015). "RAF Lakenheath was selected as the first base to host USAFE F-35s". The Aviationist. Retrieved 13 January 2015.
- Capaccio, Tony; Johnsson, Julie (31 July 2015). "Better five years late than never: U.S. Marines finally ready to declare F-35B ready for limited combat duty". National Post.
- Davenport, Christian (15 September 2015). "Pentagon weapons tester calls F-35 evaluation into question". The Washington Post.
- Bardo, J. T. (1 August 2016). Executive Summary of VMFA-121 Support of Red Flag 16-3. U.S. Marine Corps (Report).
- Lockie, Alex (8 February 2017). "The F-35 slaughtered the competition in its latest test". Business Insider.
- Cohen, Rachel (2 May 2019). "JPO Seeks to Slash F-35A Flight-Hour Costs". Air Force.
- Thompson, Mark (2 April 2013). "Costly Flight Hours". Time. ISSN 0040-781X. Retrieved 25 April 2020.
- Reim, Garrett (30 January 2020). "Lockheed Martin sees F-35 production rising to 180 units per year, despite high flying costs". Flight Global.
- "Marines Propose Rapidly Mobile F-35 Operations". Aviation Week. 16 December 2014.
- "F-35 jet used by U.S. in combat for first time". Reuters. 27 September 2018. Retrieved 27 September 2018.
- "U.S. Air Force's F-35A Lightning II arrives for first Middle East deployment". U.S. Air Force. 15 April 2019.
- "U.S. Air Force F-35As conduct first combat employment". U.S. Air Force. 30 April 2019.
- Rogoway, Tyler (17 May 2018). "The Air Force's Elite Weapons School Has Given The F-35 A New Nickname". The War Zone. Archived from the original on 13 August 2018.
- "F-35B Lightning". Royal Air Force. Retrieved 30 August 2019.
- "Major Projects Report 2008". Ministry of Defence. Archived from the original on 7 August 2012. Retrieved 23 November 2009.
- "US Marines eye UK JSF shipborne technique". Flight International. 15 June 2007. Archived from the original on 30 July 2012.
- "Royal Air Force's No. 617 Squadron to fly F-35B fighter". Airforce Technology. 19 July 2013.
- "Dambusters to be first Lightning II squadron". Ministry of Defence. 18 July 2013.
- "17 Squadron Standard Parade". Royal Air Force. 12 April 2013. Archived from the original on 28 August 2013. Retrieved 25 January 2020.
- "Third Joint Strike Fighter for the UK arrives". Royal Air Force. 28 June 2013. Archived from the original on 1 July 2013.
- "Navy's new F-35 jump jet flies from trademark ski ramp for first time". Royal Navy. 25 June 2015.
- "Military Aircraft: Written question – 60456". UK Parliament. 17 January 2017. Retrieved 4 July 2017.
- "Identity of F-35 Lightning Training Squadron Announced". Royal Air Force. 5 July 2017. Archived from the original on 28 July 2017.
- "Second Lightning Fight Jet Squadron Arrives In UK". Royal Air Force. 17 July 2019. Retrieved 25 January 2020.
- "RAF's legendary Dambusters squadron reforms to fly F-35 jets". Ministry of Defence. 18 April 2018.
- "Britain's most advanced jets touch down on home soil". Ministry of Defence. 6 June 2018.
- Nicholls, Dominic (10 January 2019). "New RAF jet 'combat ready' in face of resurgent Russia threat". The Daily Telegraph. London.
- "UK's most advanced jets deploy overseas for the first time". Ministry of Defence. 8 April 2019.
- "F-35 fighter jets join fight against IS". BBC News. 25 June 2019.
- "First UK fighter jets land onboard HMS Queen Elizabeth". Ministry of Defence. 13 October 2019.
- "F-35 Lightnings depart for Exercise RED FLAG in USA". Royal Air Force. 22 January 2020. Retrieved 25 January 2020.
- "RAAF F-35s achieve 1,000 flying hour milestone". Australian Aviation. Retrieved 21 April 2021.
- Wroe, David (3 March 2017). "Joint Strike Fighters: Australian military stealth unveiled at Avalon Airshow". The Sydney Morning Herald. Retrieved 21 April 2021.
- "PM's landing at Williamtown". Port Stephens Examiner. 10 February 2021. Retrieved 21 April 2021.
- "Israel Declares F-35I Adir Combat Capable". F-35 Lightning II. Archived from the original on 26 September 2020. Retrieved 9 December 2017.
- Novak, Jake (18 July 2019). "The F-35 has already freaked out Iran and changed everything in the Middle East". CNBC.
- Okbi, Yasser; Hashavua, Maariv (29 March 2018). "Report: Israeli stealth fighters fly over Iran". The Jerusalem Post.
- "Israel says it is the first country to use U.S.-made F-35 in combat". Reuters. 22 May 2018.
- Kubovich, Yaniv (23 May 2018). "A Message of Superiority: This Is the Israeli Army's Photo of an F-35 Over Beirut". Haaretz.
- Bachner, Michael. "Israel said to hit Iranian sites in Iraq, expanding strikes on missile shipments". The Times of Israel.
- Trevithick, Joseph. "Israel Is Getting A Single F-35 Test Jet Unlike Any Other". TheDrive.com. Retrieved 7 January 2021.
- Jennings, Gareth. "Israel receives F-35I testbed to develop national capabilities". Jane's. Retrieved 7 January 2021.
- Gross, Judah Ari. "Ministers sign off on pricey purchase of F-35s, refuelers and bombs". The Times of Israel. Retrieved 16 February 2021.
- Waldron, Greg (2 August 2012). "In Focus: Tokyo casts wary eye on Chinese airpower developments". Flight International.
- Ewing, Philip (19 June 2012). "Lockheed's comprehensive Q&A on the F-35". DoD Buzz. Archived from the original on 18 August 2012.
- "F-35 Lightning Drag Chute". Code One Magazine. 13 August 2014. Retrieved 20 January 2020.
- Hancock, Ben D. (1997). "The STOVL Joint Strike Fighter in Support of the 21st Century Marine Corps". U.S. Marine Corps – via Global Security.
- Bly, Peter (14 June 2011). "Constructability of a High Temperature Concrete Pad" (PDF). Geotechnical & Structures Laboratory, US Army Engineer Research & Development Center (ERDC). Archived from the original (PDF) on 25 April 2012. Retrieved 15 April 2014.
- Norris, Guy (24 April 2014). "Pilot reaction to flying the F-35B". Aviation Week & Space Technology. Archived from the original on 27 September 2014. Retrieved 15 September 2014.
- "F-35B STOVL-mode Flight". Defence Aviation. March 2010. Retrieved 25 November 2010.
- Kjelgaard, Chris (21 December 2007). "From Supersonic to Hover: How the F-35 Flies". Space.com.
- "Jet's name is just plane 'Awesome'". The Times of Israel. 18 April 2013.
- "Israel's first F-35 Lightning II takes flight". Lockheed Martin. 26 July 2016. Archived from the original on 28 July 2017. Retrieved 4 August 2016.
- Ben-David, Alon (27 August 2010). "Israel To Buy F-35s With Cockpit Mods". Aviation Week.
- Ben-David, Alon; Butler, Amy & Wall, Robert (7 July 2011). "Israel, U.S. Strike F-35 Technology Deal". Aviation Week.
- David, Eshel; Fulghum, David (6 August 2012). "Israel, U.S. Agree To $450 Million In F-35 EW Work". Aviation Week. Archived from the original on 10 May 2013.
- Trimble, Stephen (22 January 2010). "Israel sets sights on two-seater F-35". Flight International.
- Egozi, Arie (11 January 2008). "Israel to boost range of future F-35 fleet". Flight International.
- "AF releases Future Operating Concept". Secretary of the Air Force Public Affairs Command Information. 15 September 2015.
- Eaglen, Mackenzie; Berger, Rick (15 September 2015). "20 technologies that will keep the US Air Force flying high". American Enterprise Institute.
- Daly, Brian (1 September 2010). "Harper, Ignatieff spar over fighter jets". Calgary Sun. Archived from the original on 2 March 2014. Retrieved 2 March 2014.
- Berthiaume, Lee (20 December 2012). "Military will contract out air-to-air refuelling if Canada goes with F-35". Canada.com. Archived from the original on 2 March 2014. Retrieved 2 March 2014.
- Yalkin, Tolga R.; Weltman, Peter (10 March 2011). "An Estimate of the Fiscal Impact of Canada's Proposed Acquisition of the F-35 Lightning II Joint Strike Fighter" (PDF). Office of the Parliamentary Budget Office. Archived (PDF) from the original on 2 March 2014.
- "A New Plan For a Strong Middle Class" (PDF). Liberal Party of Canada. 5 October 2015. Archived from the original (PDF) on 14 October 2015. Retrieved 5 October 2015.
- Waldron, Greg (27 December 2020). "RAAF F-35As achieve initial operational capability". Flight Global.
- "F-35A Lightning II". Australian Air Force. 14 June 2018.
- Emmott, Robin (25 October 2018). "Belgium picks Lockheed's F-35 over Eurofighter on price". Reuters. Brussels. Archived from the original on 25 October 2018.
- "Luchtmachtbasissen moeten verbouwd worden voor F-35: 275 miljoen euro". Het Nieuwsblad (in Dutch). 8 July 2019. Archived from the original on 8 July 2019.
- "Agreement on Procurement for New Fighters" (PDF). Danish Ministry of Defence (in Danish). Retrieved 9 June 2016.
- Gross, Judah Ari. "Israel receives 3 more F-35 fighter jets". www.timesofisrael.com. Retrieved 14 May 2021.
- Mathew, Arun. "Unique F-35I Test Aircraft Arrives in Israel". DefPost. Retrieved 7 January 2021.
- Gross, Judah Ari. "Two more F-35 fighter jets land in Israel, bringing IAF's declared total to 16". The Times of Israel.
- Ahronheim, Anna (26 November 2018). "Air Force Bolsters Stealth Power as More F-35I Fighter Jets Land in Israel". The Jerusalem Post.
- Hunter, Jamie; Newdick, Thomas (10 August 2020). "Israel Now Has Two Combat Ready F-35 Squadrons". The Drive.
- Kington, Tom (28 May 2020). "Italy defense minister commits to F-35 after calls to suspend program". Defense News. Retrieved 13 January 2021.
- Kington, Tom (21 October 2020). "Italy's Navy-Air Force tussle over the F-35 comes to a head". Defense News. Retrieved 14 January 2021.
- "F-35 Lightning II: Creating Jobs. Securing Italy's Future" (PDF). F35.com. Lockheed Martin. February 2017. Archived from the original (PDF) on 7 July 2017. Retrieved 14 January 2021.
Aeronautica Militare is programmed to receive 60 F-35A CTOLs and 15 F-35B STOVLs, while Marina Militare is programmed to acquire 15 F-35B STOVLs.
- Gady, Franz-Stefan (1 April 2019). "Japan Air Self Defense Force Stands Up First F-35A Lightning II Fighter Squadron". The Diplomat.
- Kelly, Tim; Kubo, Nobuhiro (21 February 2018). "Exclusive: Japan to buy at least 20 more F-35A stealth fighters". Reuters. Retrieved 21 February 2018.
- Harding, Robin (18 December 2018). "Japan to expand military with 100 more F-35 stealth fighters". Financial Times. Retrieved 10 January 2019.
- Vliegbasis Leeuwarden [@VlbLeeuwarden] (25 March 2021). "Welcome @VlbLeeuwarden F-017!!!" (Tweet). Retrieved 29 March 2021 – via Twitter.
- "World Air Forces 2014" (PDF). Flight Global Insight. 2014. Archived from the original (PDF) on 1 February 2014.
- "Netherlands Orders Eight F-35s". Aviation Week. Retrieved 25 May 2015.
- "Defence spending to be stepped up, more tanks and F-35 jets". DutchNews.nl. Retrieved 15 December 2018.
- Dalløkken, Per Erlien (26 May 2020). "Flere jagerfly til Ørland: Nå har Norge mottatt halve F-35-flåten". Teknisk Ukeblad (in Norwegian). Retrieved 12 August 2020.
- "Northrop Grumman completes center fuselage for first Norwegian F-35 aircraft". F-35 Lightning II. Archived from the original on 24 June 2017. Retrieved 31 March 2015.
- Vavasseur, Xavier (4 September 2020). "South Korea to Double Down on F-35 and Procure STOVL Variant for LPX-II". Naval News. Retrieved 9 April 2021.
- Waldron, Greg. "USA approves $675 million support package for Korean F-35s". Flight Global. Retrieved 13 January 2021.
- Waldron, Greg (18 December 2019). "F-35A formally enters South Korean service". Flight Global.
- "South Korea plans to buy 20 additional F-35 aircraft: report". Reuters. 20 December 2017.
- Farley, Robert (2 January 2018). "Who Wants to Operate Carrier-Based F-35Bs in Asia? Apparently, Japan and South Korea". The Diplomat.
- "S. Korea begins procedures to introduce F-35B fighters for light aircraft carrier". Yonhap News Agency. 5 August 2020.
- "Singapore – F-35B Short Take-Off and Vertical Landing (STOVL) Aircraft". Defense Security Cooperation Agency. 9 January 2020. Retrieved 12 January 2020.
- "Türk pilotlar F-35 eğitimine başlıyor" [Turkish pilots start F-35 training]. Hürriyet. 3 July 2018. Retrieved 6 November 2020.
- "Turkish F-35 delivered to training base in Arizona, official says". Reuters. 4 April 2019.
- "F-35 teslimat töreni başladı" [F-35 delivery ceremony started]. kokpit.aero (in Turkish). 21 June 2018. Archived from the original on 21 June 2018.
- "Turkey to Order Four More F-35 Fighter Jets". F-35.com. Archived from the original on 21 November 2019. Retrieved 24 November 2016.
- "Turkey Plans More F-35 Orders After Receiving First Batch in 2018". Haaretz. Reuters. 28 October 2016.
- Pawlyk, Oriana (16 June 2019). "Trump: Turkey Will Be Out of F-35 Fighter Jet Program After S-400 Buy". Military.com.
- "White House moves forward with sale of F-35s to UAE". Al-Jazeera. 4 November 2020.
- "Biden suspends F-35 sale to UAE". Daily Sabah. 27 January 2021.
- Axelrod, Tal (13 April 2021). "Biden to move ahead with $23 billion UAE weapons sale approved by Trump". The Hill. Archived from the original on 14 April 2021. Retrieved 14 April 2021.
- Sharma, Aakriti (2 December 2020). "More F-35 Stealth Jets Join The British Royal Air Force After PM Boris Johnson's Defense Budget Hike". Eurasian Times.com. Retrieved 16 January 2021.
- "Further five F-35 fighter jets land at new RAF Marham home". ITN News. 4 August 2018.
- "Lockheed Martin-Built F-35 Comes Home to RAF Marham". F35.com. Lockheed Martin. Archived from the original on 14 September 2020. Retrieved 19 June 2018.
- "UK receives final F-35 test aircraft". Janes Defence Weekly. 53 (16). 20 April 2016.
- Urban, Mark (24 November 2015). "Defence Review: Fighting old battles?". BBC News. Retrieved 24 November 2015.
- "Global Participation: United States". F35.com. Retrieved 30 April 2014.
- Reim, Garrett (18 April 2018). "DOD reveals F-35 multiyear procurement strategy to start in 2021". Flight Global.
- Malenic, Marina (17 June 2015). "Pentagon releases report on F-35 engine failure". IHS Jane's Defence Weekly. 52 (24): 13.
- Shalal, Andrea (27 June 2014). "Engine pieces found on runway after F-35 fire". Reuters. Archived from the original on 15 October 2015. Retrieved 1 July 2017.
- Butler, Amy. "Blade 'Rubbing' At Root of F-35A Engine Fire". Aviation Week. Retrieved 14 July 2014.
- Mehta, Aaron (15 July 2014). "Breaking: F-35 Cleared For Flight". Defense News. Archived from the original on 17 July 2014. Retrieved 15 July 2014.
- "F-35B Lightning II fighter jet crashes, pilot ejects in South Carolina". Stripes.com. Retrieved 28 September 2018.
- Sonne, Paul (28 September 2018). "F-35 crashes for the first time in the jet's 17-year history, pilot ejects safely". The Washington Post.
- Macias, Amanda; Breuninger, Kevin (11 October 2018). "Pentagon grounds Lockheed Martin's F-35 jets after South Carolina crash". CNBC.
- Losey, Stephen (12 October 2018). "Some Air Force, Navy F-35s resume flying after grounding". Air Force Times.
- "F-35 stealth fighter that crashed off Japan didn't send distress signal before Pacific plunge". The Japan Times. 11 April 2019.
- Yeo, Mike (12 April 2019). "F-35A crash: Japan's defense minister addresses security concerns, procurement plans". Defense News.
- "Report: New Japanese F-35s made seven emergency landings leading up to crash in the Pacific". NEWSREP. 19 April 2019.
- "Japan Finds Wreckage From F-35 Fighter Jet, but Pilot Is Still Missing". The New York Times. 10 April 2019.
- "F-35A stealth fighter crashes upon landing at Eglin AFB; pilot is in stable condition". Stars and Stripes. 19 May 2020.
- "Japanese F-35 fighter jet disappears over Pacific during exercise". Kyodo News. 10 April 2019.
- Kelly, Tim (11 April 2019). "Daunting salvage task awaits Japanese F-35 investigators baffled by crash". Reuters.
- Lendon, Brad; Wakatsuki, Yoko. "Japan F-35 fighter crash: Pilot suffered 'spatial disorientation'". CNN. Retrieved 11 June 2019.
- "United States Air Force Aircraft Accident Investigation Board Report" (PDF). Retrieved 26 October 2020.
- Martinez, Luis (30 September 2020). "Marine F-35 jet crashes after clipping wings with refueling plane". ABC News.
- Lockheed Martin. "F-35A Conventional Takeoff and Landing Variant". Archived from the original on 17 March 2011. Retrieved 13 July 2012.
- "F-35A Lightning II". af.mil. Retrieved 25 November 2017.
- "F-35B Short Takeoff/Vertical Landing Variant". Lockheed Martin. Archived from the original on 17 March 2011. Retrieved 13 July 2012.
- "F-35C Carrier Variant". Lockheed Martin. Archived from the original on 17 March 2011. Retrieved 13 July 2012.
- "F-35 Weaponry". F35.com. Lockheed Martin. Archived from the original on 18 April 2019. Retrieved 28 February 2019.
- "FY2019 President's Budget Selected Acquisition Report (SAR) – F-35 Joint Strike Fighter Aircraft (F-35)" (PDF). www.esd.whs.mil. Archived from the original (PDF) on 10 March 2019.
- "FY2016 DOT&E Report – F-35 Joint Strike Fighter Aircraft (F-35)" (PDF). dote.osd.mil. 2017. p. 15. Archived from the original (PDF) on 13 July 2017.
- North, Gary (April 2016). "Long Combat Radius" (PDF). F-35: The Future is Now. Fisher.org.il.
- Ewing, Philip (3 July 2012). "The Navy's advanced weapons shopping list". DoD buzz.com. Archived from the original on 6 September 2012. Retrieved 2 February 2021.
- "Nuclear Posture Review Report" (PDF). U.S. Department of Defense. Washington, D.C. April 2010. Archived from the original (PDF) on 7 December 2014.
- Hamstra, Jeffrey (2019). Hamstra, Jeffrey W. (ed.). The F-35 Lightning II: From Concept to Cockpit. American Institute of Aeronautics and Astronautics (AIAA). doi:10.2514/4.105678. ISBN 978-1-62410-566-1.
- Keijsper, Gerald (2007). Lockheed F-35 Joint Strike Fighter. London: Pen & Sword Aviation. ISBN 978-1-84415-631-3.
- Lake, Jon. "The West's Great Hope". AirForces Monthly, December 2010.
- Polmar, Norman (2005). The Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet. Annapolis, MD: Naval Institute Press. ISBN 978-1-59114-685-8.
- Borgu, Aldo (2004). A Big Deal: Australia's Future Air Combat Capability. Canberra: Australian Strategic Policy Institute. ISBN 1-920722-25-4.
- Spick, Mike (2002). The Illustrated Directory of Fighters. London: Salamander. ISBN 1-84065-384-1.
- Winchester, Jim (2005). Concept Aircraft: Prototypes, X-Planes, and Experimental Aircraft. San Diego, CA: Thunder Bay Press. ISBN 978-1-59223-480-6. OCLC 636459025.
|Wikimedia Commons has media related to: F-35 Lightning II (category)|
|Wikiquote has quotations related to: Lockheed Martin F-35 Lightning II|