Lockheed Martin F-35 Lightning II

"Joint Strike Fighter" redirects here. For other uses, see Joint Strike Fighter (disambiguation).

F-35 Lightning II
An F-35A Lightning II, marked AA-1, lands at Edwards Air Force Base, Calif.
Role	Stealth multirole fighter
First flight	15 December 2006
Introduction	2014 (USMC) 2014 (USAF) 2016 (USN)
Status	Under development, in flight testing
Produced	2003–present
Number built	13 flight-test aircraft; 15 LRIP aircraft on order.
Developed from	Lockheed Martin X-35

The Lockheed Martin F-35 Lightning II is a fifth-generation, single-seat, single-engine stealth multirole fighter that can perform close air support, tactical bombing, and air defense missions. The F-35 has three different models; one is a conventional takeoff and landing variant, the second is a short take off and vertical-landing variant, and the third is a carrier-based variant.

The F-35 is descended from the X-35, the product of the Joint Strike Fighter (JSF) program. Its development is being principally funded by the United States, with the United Kingdom and other partner governments providing additional funding. It is being designed and built by an aerospace industry team led by Lockheed Martin with Northrop Grumman and BAE Systems as major partners. The X-35 demonstrator first flew in 2000, and the F-35's first flight took place on 15 December 2006.

The United States intends to buy a total of 2,443 aircraft for an estimated US$323 billion, making it the most expensive defense program ever. The USAF's budget data in 2010 projects the F-35 to have a US$89 million flyaway cost over its planned production of 1,753 F-35As. Lockheed Martin expects to reduce government cost estimates by 20%.

Development

JSF Program history

Main article: Joint Strike Fighter Program

Requirement

An F-35 wind tunnel testing model in the Arnold Engineering Development Center's 16-foot transonic wind tunnel

The JSF program was designed to replace the U.S. military's F-16, A-10, F/A-18 (excluding newer E/F "Super Hornet" variants) and AV-8B tactical fighter aircraft. To keep development, production, and operating costs down, a common design was planned in three variants that share 80% of their parts:

• F-35A, conventional take off and landing (CTOL) variant.
• F-35B, short-take off and vertical-landing (STOVL) variant.
• F-35C, carrier-based CATOBAR (CV) variant.

The F-35 is intended to be the world's premier strike aircraft through 2040, with close- and long-range air-to-air capability second only to that of the F-22 Raptor. The F-35 is required to be four times more effective than existing fighters in air-to-air combat, eight times more effective in air-to-ground combat, and three times more effective in reconnaissance and suppression of air defenses – while having better range and requiring less logistics support.

Lockheed Martin has suggested that the F-35 could also replace the USAF's F-15C/D air superiority fighter and F-15E Strike Eagles in the air superiority role.

With takeoff weights up to 60,000 lb (27,000 kg), the F-35 is considerably heavier than the lightweight fighters it replaces. In empty and maximum gross weights, it more closely resembles the single-seat, single-engine F-105 Thunderchief, which was the largest single-engine fighter of the Vietnam era.

Origins and selection

The Joint Strike Fighter evolved out of several requirements for a common fighter to replace existing types. The actual JSF development contract was signed on 16 November 1996.

The contract for System Development and Demonstration (SDD) was awarded on 26 October 2001 to Lockheed Martin, whose X-35 beat the Boeing X-32. Although both met or exceeded requirements, the X-35 exceeded each requirement. The design was considered to have less risk and more growth potential. The designation of the fighter as "F-35" came as a surprise to Lockheed, which had been referring to the aircraft in-house by the designation "F-24".

Design phase

F-35 Lightning II USAF video

Based on wind tunnel testing, Lockheed Martin slightly enlarged its X-35 design into the F-35. The forward fuselage is 5 inches (130 millimetres) longer to make room for avionics. Correspondingly, the horizontal stabilators were moved 2 inches (51 millimetres) rearward to retain balance and control. The top surface of the fuselage was raised by 1 inch (25 millimetres) along the centerline. Also, it was decided to increase the size of the F-35B STOVL variant's weapons bay to be common with the other two variants.

The F-35B STOVL variant was in danger of missing performance requirements in 2004 because it weighed too much – reportedly, by 2,200 pounds (1,000 kg) or 8 percent. In response, Lockheed Martin added engine thrust and shed more than a ton by thinning the aircraft's skin; reducing the size of the common weapons bay and vertical stabilizers; re-routing some thrust from the roll-post outlets to the main nozzle; and redesigning the wing-mate joint, portions of the electrical system, and the portion of the aircraft immediately behind the cockpit. Many of the changes were applied to all three variants to maintain high levels of commonality. By September 2004, the weight reduction effort had reduced the aircraft's design weight by 2,700 pounds (1,200 kilograms).

On 7 July 2006, the US Air Force officially announced the name of the F-35: Lightning II, in honor of Lockheed's World War II-era twin-prop P-38 Lightning and the Cold War-era jet, the English Electric Lightning. English Electric Company's aircraft division was a predecessor of F-35 partner BAE Systems. Lightning II was also an early company name for the aircraft that became the F-22 Raptor.

On 19 December 2008, Lockheed Martin rolled out the first weight-optimized F-35A (designated AF-1). It is the first F-35 to be produced at a full-rate production speed and is structurally identical to the production F-35As that will be delivered starting in 2010.

As of 5 January 2009, six F-35s are complete, including AF-1 and AG-1, and 17 are in production. "Thirteen of the 17 in production are pre-production test aircraft, and all of those will be finished in 2009," said John R. Kent, acting manager of F-35 Lightning II Communications at Lockheed Martin Aeronautics Company. "The other four are the first production-model planes, and the first of those will be delivered in 2010 to the U.S. Air Force, and will go to Eglin." On 6 April 2009, US Secretary of Defense Robert Gates proposed speeding up production for the US to buy 2,443 F-35s.

On 21 April 2009 media reports, citing Pentagon sources, said that during 2007 and 2008, computer spies managed to copy and siphon off several terabytes of data related to F-35's design and the electronics systems, potentially enabling the development of defense systems against the aircraft. However, Lockheed Martin has rejected suggestions that the project has been compromised, saying that it "does not believe any classified information had been stolen".

On 9 November 2009, Ashton Carter, under-secretary of defense for acquisition, technology and logistics, acknowledged that the Pentagon "joint estimate team" (JET) had found possible future cost and schedule overruns in the project and that he would be holding meetings to attempt to avoid these. On 1 February 2010, Gates removed JSF Program Manager Marine Maj. Gen. David Heinz and withheld $614 million in payments to Lockheed Martin because of program costs and delays.

On 11 March 2010, a report from the Government Accountability Office to United States Senate Committee on Armed Services projected the overall unit cost of an F-35A to be $112m in today's money. In 2010 Pentagon officials disclosed that the F-35 program has exceeded its original cost estimates by more than 50 percent. An internal Pentagon report critical of the JSF project states that "affordability is no longer embraced as a core pillar".

On 24 March 2010, Gates termed the recent cost overruns and delays as "unacceptable" in a testimony before the U.S. Congress. He characterized previous cost and schedule estimates for the project as "overly rosy". However, Gates insisted the F-35 would become "the backbone of U.S. air combat for the next generation" and informed the Congress that he had expanded the development period by an additional 13 months and budgeted $3 billion more for the testing program while slowing down production.

Design

F-35B's thrust vectoring nozzle and lift fan

The F-35A being towed to its inauguration ceremony on 7 July 2006

The F-35 appears to be a smaller, slightly more conventional, single-engine sibling of the sleeker, twin-engine F-22 Raptor, and indeed drew elements from it. The exhaust duct design was inspired by the General Dynamics Model 200 design, which was proposed for a 1972 supersonic VTOL fighter requirement for the Sea Control Ship. For specialized development of the F-35B STOVL variant, Lockheed consulted with the Yakovlev Design Bureau, purchasing design data from their development of the Yakovlev Yak-141 "Freestyle". Although several experimental designs have been built and tested since the 1960s including the Navy's unsuccessful Rockwell XFV-12, the F-35B is to be the first operational supersonic STOVL fighter.

The F-35 is designed to be America's "premier surface-to-air missile killer and is uniquely equipped for this mission with cutting edge processing power, synthetic aperture radar integration techniques, and advanced target recognition."

Some improvements over current-generation fighter aircraft are:

• Durable, low-maintenance stealth technology, using structural fiber mat instead of the high-maintenance coatings of legacy stealth platforms;
• Integrated avionics and sensor fusion that combine information from off- and on board sensors to increase the pilot's situational awareness and improve target identification and weapon delivery, and to relay information quickly to other command and control (C2) nodes;
• High speed data networking including IEEE 1394b and Fibre Channel.
• The Autonomic Logistics Global Sustainment (ALGS), Autonomic Logistics Information System (ALIS) and Computerized Maintenance Management System (CMMS) help ensure aircraft uptime with minimal maintenance manpower.
• Electrohydrostatic actuators run by a power-by-wire flight-control system.

The majority of the structural composites in the F-35 are made out of bismaleimide (BMI) and composite epoxy material.

Engines

The F-35's main engine is the Pratt & Whitney F135. The General Electric/Rolls-Royce F136 is being developed as an alternate engine. The F135/F136 engines are not designed to supercruise in the F-35. The STOVL versions of both power plants use the Rolls-Royce LiftSystem, patented by Lockheed Martin and built by Rolls-Royce. This system is more like the Russian Yak-141 and German VJ 101D/E than the preceding generation of STOVL designs, such as the Harrier Jump Jet in which all of the lifting air went through the main fan of the Rolls-Royce Pegasus engine.

The Lift System is composed of a lift fan, drive shaft, two roll posts and a "Three Bearing Swivel Module" (3BSM). The 3BSM is a thrust vectoring nozzle which allows the main engine exhaust to be deflected downward at the tail of the aircraft. The lift fan near the front of the aircraft provides a counter-balancing thrust. Somewhat like a vertically mounted turbofan within the forward fuselage, the lift fan is powered by the engine's low-pressure (LP) turbine via a drive shaft and gearbox. Roll control during slow flight is achieved by diverting pressurized air from the LP turbine through wing mounted thrust nozzles called Roll Posts.

The F-35B's lift fan achieves the same 'flow multiplier' effect as the Harrier's huge, but supersonically impractical, main fan. Like lift engines, this added machinery is just dead weight during horizontal flight but provides a net increase in payload capacity during vertical flight. The cool exhaust of the fan also reduces the amount of hot, high-velocity air that is projected downward during vertical take off (which can damage runways and aircraft carrier decks). Though complicated and risky, the lift system has been made to work to the satisfaction of DOD officials.

To date, F136 funding has come at the expense of other parts of the program, reducing the number of aircraft built and increasing their costs. The F136 team has claimed that their engine has a greater temperature margin which may prove critical for VTOL operations in hot, high altitude conditions.

In late 2008 the Air Force revealed that the F-35 would be about twice as loud at takeoff as the F-15 Eagle and up to four times as loud upon landing. As a result, residents near Luke Air Force Base, Arizona and Eglin Air Force Base, Florida, possible homes of the jet, have requested that the Air Force conduct environmental impact studies concerning the F-35's noise levels. The city of Valparaiso, Florida, adjacent to Eglin AFB, threatened in February 2009 to sue the Air Force over the impending arrival of the F-35s, but this lawsuit was settled in March 2010. Moreover, it was reported in March 2009 that testing by Lockheed Martin and the Royal Australian Air Force revealed that the F-35 was not as loud as first reported, being "only about as noisy as an F-16 fitted with a Pratt & Whitney F100-PW-200 engine" and "quieter than the Lockheed Martin F-22 Raptor and the Boeing F/A-18E/F Super Hornet."

Armament

Weapons bay on a mock-up of the F-35

The F-35 includes a GAU-22/A four-barrel 25mm cannon. The cannon will be mounted internally with 180 rounds in the F-35A and fitted as an external pod with 220 rounds in the F-35B and F-35C. The gun pod for the B and C variants will have stealth features. This pod could be used for different equipment in the future, such as EW, reconnaissance equipment, or possibly a rearward facing radar.

Internally (current planned weapons for integration), up to two air-to-air missiles and two air-to-air or air-to-ground weapons (up to two 2,000 lb bombs in A and C models (BRU-68); two 1,000 lb bombs in the B model (BRU-67)) can be carried in the bomb bays. These could be AIM-120 AMRAAM, AIM-132 ASRAAM, the Joint Direct Attack Munition (JDAM) – up to 2,000 lb (910 kg), the Joint Stand off Weapon (JSOW), Small Diameter Bombs (SDB) – a maximum of four in each bay (Three per bay in F-35B), the Brimstone anti-armor missiles, and Cluster Munitions (WCMD). The MBDA Meteor air-to-air missile is currently being adapted to fit internally in the missile spots and may be integrated into the F-35. The UK had originally planned to put up to four AIM-132 ASRAAM internally but this has been changed to carry 2 internal and 2 external ASRAAMs. It has also been stated by a Lockheed executive that the internal bay will eventually be modified to accept up to 6 AMRAAMs.

At the expense of being more detectable by radar, many more missiles, bombs and fuel tanks can be attached on four wing pylons and two near wingtip positions. The two wingtip locations can only carry AIM-9X Sidewinder. The other pylons can carry the AIM-120 AMRAAM, Storm Shadow, AGM-158 Joint Air to Surface Stand-off Missile (JASSM) cruise missiles, guided bombs, 480-gallon and 600-gallon fuel tanks. An air-to-air load of eight AIM-120s and two AIM-9s is conceivable using internal and external weapons stations, as well as a configuration of six 2,000 lb bombs, two AIM-120s and two AIM-9s. With its payload capability, the F-35 can carry more weapons payload than legacy fighters it is to replace as well as the F-22 Raptor. Solid-state lasers were being developed as optional weapons for the F-35 as of 2002.

Stealth

Landing gear door of the F-35, showing its stealthy design

The F-35 has a low radar cross section primarily due to the materials used in construction, including fibre-mat. The F-35 also has a more stealthy shape than past fighters, including a zigzag-shape weapons bay and landing gear door.

The Teen Series of fighters (F-15, F-16, F/A-18) were notable for always carrying large external fuel tanks, but as a stealth aircraft the F-35 must fly most missions on internal fuel. Unlike the F-16 and F/A-18, the F-35 lacks leading edge extensions (LEX) and instead uses stealth-friendly chines for vortex lift in the same fashion as the SR-71 Blackbird. The small bumps just forward of the engine air intakes form part of the diverterless supersonic inlet (DSI) which is a simpler, lighter and stealthier means to ensure high-quality airflow to the engine over a wide range of conditions.

In spite of being smaller than the F-22, the F-35 has a larger radar cross section. It is said to be roughly equal to a metal golf ball rather than the F-22's metal marble.

Cockpit

The F-35 features a full-panel-width "panoramic cockpit display" (PCD) glass cockpit, with dimensions of 20 by 8 inches (50 by 20 centimeters). A cockpit speech-recognition system (Direct Voice Input) provided by Adacel is planned to improve the pilot's ability to operate the aircraft over the current-generation interface. The F-35 will be the first US operational fixed-wing aircraft to use this system, although similar systems have been used in AV-8B and trialled in previous US jets, particularly the F-16 VISTA. The pilot flies the aircraft by means of a right-hand side stick and left-hand throttle.

A helmet-mounted display system (HMDS) will be fitted to all models of the F-35. A helmet-mounted cueing system is already in service with the F-15s, F-16s and F/A-18s. While some fighters have offered HMDS along with a head up display (HUD), this will be the first time in several decades that a front-line tactical jet fighter has been designed to not carry a HUD.

The Martin-Baker US16E ejection seat is used in all F-35 variants. The US16E seat design balances major performance requirements, including safe-terrain-clearance limits, pilot-load limits, and pilot size. It uses a twin-catapult system that is housed in side rails.

Sensors and avionics

Electro-optical target system (EOTS) under the nose of a mockup of the F-35

The F-35's sensor and communications suite provides situational awareness, command-and-control and network-centric warfare capability. The main sensor on board the F-35 is its AN/APG-81 AESA-radar, designed by Northrop Grumman Electronic Systems. It is augmented by the Electro-Optical Targeting System (EOTS) mounted under the nose of the aircraft, designed by Lockheed Martin. This gives the same capabilities as the Lockheed Martin Sniper XR without compromising the aircraft's stealth.

Six additional passive infrared sensors are distributed over the aircraft as part of Northrop Grumman's AN/AAQ-37 distributed aperture system (DAS), which acts as a missile warning system, reports missile launch locations, detects and tracks approaching aircraft spherically around the F-35, and replaces traditional night vision goggles for night operations and navigation. All DAS functions are performed simultaneously, in every direction, at all times. The F-35's AN/ASQ-239 (Barracuda) Electronic Warfare systems are designed by BAE Systems and include Northrop Grumman components. The communications, navigation and identification (CNI) suite is designed by Northrop Grumman and includes the Multifunction Advanced Data Link (MADL). The F-35 will be the first jet fighter that has sensor fusion that combines both radio frequency and IR tracking for continuous target detection and identification in all directions which is shared via MADL to other platforms without compromising their low observability.

As a fifth generation fighter, the F-35 is not a federated collection of equipment. All of the sensors feed directly into the main processors to support the entire mission of the aircraft. For example the AN/APG-81 functions not just as a multi-mode radar, but also as part of the aircraft's electronic warfare system.

Unlike older generations of aircraft, such as the F-22, all software for the F-35 is written in C++ for faster code development. The Integrity DO-178B real-time operating system (RTOS) from Green Hills Software runs on COTS Freescale PowerPC processors.

The final Block 3 software for the F-35 is planned to have 8.6 million lines of software code.

Helmet-Mounted Display System

Helmet-Mounted Display System

Rather than maneuvering with thrust vectoring, or canards to line up the target directly ahead of the aircraft, like 4.5 Generation jet fighters, the F-35 does not need to point at the target to hit it. It uses combined radio frequency and infra red (SAIRST) "situational awareness" to continually track all nearby aircraft, the pilot's helmet-mounted display system (HMDS) for displaying and selecting targets, and High Off-Boresight (HOBS) weapons. The helmet system replaces the display suite-mounted head-up display used in previous generation fighters. Because of this, Northrop Grumman claims that "maneuvering is irrelevant".

The F-35's systems provide the edge in the "observe, orient, decide, and act" OODA loop; Stealth and advanced sensors aid in observation, automated target tracking helps in orientation, sensor fusion simplifies decision making, and the aircraft's controls allow action against targets without having to look away from them.

Concerns over performance

Concerns about the F-35's performance have resulted partially from reports of simulations by RAND Corporation in which numerous Russian Sukhoi fighters defeat a handful of F-35s by denying tanker refueling. As a result of these media reports, then Australian defence minister Joel Fitzgibbon requested a formal briefing from the Australian Department of Defence on the simulation. This briefing stated that the reports of the simulation were inaccurate and that it did not compare the F-35's performance against that of other aircraft.

Maj. Richard Koch, chief of USAF Air Combat Command’s advanced air dominance branch is reported to have said that “I wake up in a cold sweat at the thought of the F-35 going in with only two air-dominance weapons.”

This criticism of the F-35 has been dismissed by the Pentagon and Lockheed Martin as these simulations did not address air-to-air combat. RAND has disavowed the critical remarks about the F-35 for the same reason and stated that no analysis was provided at that time regarding the performance of the F-35. The USAF has conducted an analysis of the F-35's air-to-air performance against all 4th generation fighter aircraft currently available, and has found the F-35 to be at least four times more effective. Major General Charles R. Davis, USAF, the F-35 program executive officer, has stated that the "F-35 enjoys a significant Combat Loss Exchange Ratio advantage over the current and future air-to-air threats, to include Sukhois". The Russian, Indian, Chinese, and other air forces operate Sukhoi Su-27/30 fighters.

In a similar RAND Corporation tanker-denial scenario, three regiments of Chinese Sukhoi Su-27s defeated six F-22 Raptors by avoiding the fighters and destroying the refueling tankers.

Andrew Krepinevich has questioned the reliance on a short ranged aircraft like the F-35 to 'manage' China in a future conflict and has called on reducing the F-35 buy in favor of a longer ranged platform like the Next-Generation Bomber, but former United States Secretary of the Air Force Michael Wynne rejected this plan of action back in 2007.

Chen Hu, editor-in-chief of World Military Affairs magazine has said that the F-35 is too costly because it attempts to provide the capabilities needed for all three American services in a common airframe. Dutch news program NOVA show interviewed US defense specialist Winslow T. Wheeler and aircraft designer Pierre Sprey who called the F-35 "heavy and sluggish" as well as having a "pitifully small load for all that money", and went on to criticize the value for money of the stealth measures as well as lacking fire safety measures. His final conclusion was that any air force would be better off maintaining its fleets of F-16s and F/A-18s compared to buying into the F-35 program. Like the Bell-Boeing V-22 Osprey, the F-35B sends jet thrust directly downwards during vertical takeoffs and landing and the nozzle is being redesigned to spread the output out in an oval rather than a small circle so as to limit damage to asphalt and ship decks.

Manufacturing responsibilities

Lockheed Martin Aeronautics is the prime contractor and performs aircraft final assembly, overall system integration, mission system, and provides forward fuselage, wings and flight controls system. Northrop Grumman provides Active Electronically Scanned Array (AESA) radar, Infra red Distributed Aperture System (DAS), Communications, Navigation, Identification (CNI), center fuselage, weapons bay, and arrestor gear. BAE Systems provides aft fuselage and empennages, horizontal and vertical tails, crew life support and escape systems, Electronic warfare systems, fuel system, and Flight Control Software (FCS1). Alenia will perform final assembly for Italy and, according to an Alenia executive, assembly of all European aircraft with the exception of Turkey and the United Kingdom.

As an international program, countries that help build the F-35 will form a competitive marketplace where parts and maintenance contracts are traded. On 24 November 2009, Jon Schreiber said that the United States will not share the software code for the F-35 with its allies.

Next Generation Jammer

The USMC is considering replacing their EA-6B Prowler Electronic Attack aircraft with F-35s that have stealthy jammer pods attached.

On 30 September 2008, the United States Navy outlined the basic requirements of the NGJ and stated that the design must be modular and open. Kent, John R. et al. The Navy has selected four companies to submit designs for the Next Generation Jammer.

The NGJ will also have cyber attack capabilities where the AESA radar is used to insert attack codes into remote systems.

The ITT-Boeing design for the NGJ includes six AESA arrays for all around coverage. The team has been awarded a $42 million contract to develop their design based on ITT's strength with broadband electronically steerable antenna arrays. At the same time contracts were also awarded to Raytheon, Northrop Grumman and BAE Systems.

Operational history

Testing

The first F-35A (designated AA-1) was rolled out in Fort Worth, Texas on 19 February 2006. The aircraft underwent extensive ground testing at Naval Air Station Joint Reserve Base Fort Worth in late 2006. In September 2006 the first engine run of the F135 afterburner turbofan in an airframe and tests were completed; the first time that the F-35 was completely functional on its own power systems. On 15 December 2006, the F-35A completed its maiden flight.

A modified Boeing 737-300, the Lockheed CATBird is used as an avionic test bed inside of which are racks holding all of F-35's avionics, as well as a complete F-35 cockpit.

On 31 January 2008 at Fort Worth, Texas, Lt Col James "Flipper" Kromberg of the U.S. Air Force became the first military service pilot to evaluate the F-35, taking the aircraft through a series of maneuvers on its 26th flight.

F-35 AA-1, on its 34th test flight, began aerial refueling testing in March 2008. Another milestone was reached on 13 November 2008, when the AA-1 flew at supersonic speeds for the first time, reaching Mach 1.05 at 30,000 feet (9,144 m) making four transitions through the sound barrier, for a total of eight minutes of supersonic flight.

The first F-35B (designated BF-1) made its maiden flight on 11 June 2008. The flight, which featured a conventional take off, was piloted by BAE Systems' test pilot Graham Tomlinson. The BF-1 is the second of 19 System Development and Demonstration (SDD) F-35s, and the first to use new weight-optimized design features that will apply to all future F-35s. Testing of the STOVL propulsion system in flight began on 7 January 2010. The STOVL system was used for 14 minutes of the 48 minute test flight while the aircraft slowed from 210 knots to 180 knots. The F-35B's first hover (full stop in mid-air) happened on 17 March 2010, followed by a STOVL landing, and on 18 March 2010 the first vertical landing was performed. During a test flight on 10 June 2010, the F-35B became the second STOVL aircraft to achieve supersonic speeds, the first being its ancestor, the X-35B, which achieved the same feat on 20 July 2001.

Although many of the initial flight test targets have been accomplished, the F-35 testing program completed "just under 100 sorties and about as many hours in 2.5 years" by June 2009 and was falling significantly behind schedule. A 2008 Pentagon Joint Estimate Team (JET I) estimated that the program was two years behind the latest public schedule, and a 2009 Joint Estimate Team (JET II) revised that estimate to predict a 30-month delay. Due to those delays in the testing program, production numbers will be reduced by 122 aircraft through 2015 in order to provide additional funds for development. Those additional funds will add $2.8 billion to the development funds and internal memos suggest that the official timeline will be extended by 13 months (not the 30 months the JET II team predicted the slip would be). The success of the Joint Estimate Team has led Ashton Carter to call for more such teams for other poorly performing Pentagon projects.

Nearly 30 percent of all the test flights have required more than routine maintenance to get the aircraft flyable again. Currently each F-35 takes a million more work hours than predicted and flight testing is expected to result in further design changes. The United States Navy has projected that lifecycle costs over a fleet life of 65 years for all of the American F-35s will be $442 billion higher than the U.S. Air Force has projected.

The delay in the F-35 program is expected to lead to a shortfall of only around 100 jet fighters in the Navy/Marines team, given careful management, service life extension of the Marines' legacy F/A-18s and more burdens placed on Navy fighters.

The F-35C carrier variant's maiden flight took place on 7 June 2010, also at NAS Fort Worth JRB. The 57 minute flight was executed by Lockheed test pilot Jeff "Slim" Knowles, who was the chief test pilot for the F-117 program.

A total of 11 U.S. Air Force F-35s are to arrive in Fiscal Year 2011.

International participation

While the United States is the primary customer and financial backer, the United Kingdom, Italy, the Netherlands, Canada, Turkey, Australia, Norway and Denmark have agreed to contribute US$4.375 billion toward the development costs of the program. Total development costs are estimated at more than US$40 billion (underwritten largely by the United States), while the purchase of an estimated 2,400 planes is expected to cost an additional US$200 billion. The nine major partner nations plan to acquire over 3,100 F-35s through 2035, making the F-35 one of the most numerous jet fighters.

Participant nations:

  Primary customer: USA

  Level 1 partner: UK

  Level 2 partner: Italy and the Netherlands

  Level 3 partner: Canada, Turkey, Australia, Norway and Denmark

  Security Cooperative Participants (SCP): Israel and Singapore

There are three levels of international participation. The levels generally reflect the 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. The United Kingdom is the sole "Level 1" partner, contributing US$2.5 billion, which was about 10% of the planned development costs under the 1995 Memorandum of Understanding that brought the UK into the project. Level 2 partners are Italy, which is contributing US$1 billion; and the Netherlands, US$800 million. Level 3 partners are Canada, US$475 million; Turkey, US$195 million; Australia, US$144 million; Norway, US$122 million and Denmark, US$110 million. Israel and Singapore have joined as Security Cooperative Participants (SCP).

Some of the partner countries have wavered in their public commitment to the JSF program, hinting or warning that unless they receive more subcontracts or technology transfer, they will forsake JSF for the Eurofighter Typhoon, Saab JAS 39 Gripen, Dassault Rafale or simply upgrade their existing aircraft. Furthermore, F-35 export competitiveness has been hurt by international buyers finding either its export variant too costly per unit or "watered down". While the F-16E/F costs $50 million per export copy, the F-35 is likely to cost between $65–120 million. The exported F-35 versions will be the same configuration as the U.S. versions according to Brigadier Gen. David Heinz, program executive officer in 2009.

United Kingdom

Main article: Joint Combat Aircraft

The United Kingdom planned to acquire 138 F-35Bs as of December 2006 for the Royal Air Force and the Royal Navy. But speculation mounts in 2009 that they may switch from the F-35B to the F-35C model, with its greater range and payload the UK would require fewer aircraft and save about $25 million for each aircraft ordered.

The UK became increasingly frustrated by a lack of U.S. commitment to grant access to the technology that would allow the UK to maintain and upgrade its F-35s without US involvement. This is understood to relate mainly to the software for the aircraft. For five years, British officials sought an ITAR waiver to secure greater technology transfer. This request, which had the blessing of the Bush administration, was repeatedly blocked by U.S. Representative Henry Hyde, who said that the UK needed to tighten its laws protecting against the unauthorized transfer of the most advanced U.S. technology to third parties.

On 27 May 2006, President George W. Bush and Prime Minister Tony Blair announced that "Both governments agree that the UK will have the ability to successfully operate, upgrade, employ, and maintain the Joint Strike Fighter such that the UK retains operational sovereignty over the aircraft." On 12 December 2006, Lord Drayson signed an agreement which met the UK's demands for further participation, i.e., access to software source code and operational sovereignty. The agreement allows "an unbroken British chain of command" for operation of the aircraft. Drayson said Britain would "not be required to have a US citizen in our own operational chain of command". Drayson also said, however, that Britain is still considering an unspecified "Plan B" alternative to buying the Joint Strike Fighter.

On 25 July 2007, the Ministry of Defence confirmed that they have placed orders for the two new aircraft carriers of the Queen Elizabeth class that will allow the purchase of the F-35B variant. On 2 May 2008, however, the Washington Post reported that an Inspector General's report chided the U.S. Department of Defense's Defense Security Service for failing to ensure that BAE Systems was exercising appropriate controls over access to sensitive technologies, while both BAE and Lockheed Martin denied that any technology had been compromised.

On 18 March 2009, Defence Secretary John Hutton announced the MoD had agreed to purchase three test F-35Bs, and on 22 December 2009 financial approval for the purchase of the third aircraft was given.

On 26 January 2010, following over 18 months of simulator training, Squadron Leader Steve Long, by completing a test flight, became the first UK active duty pilot to fly the F-35.

Italy

Italy is the second largest contributor partner after the UK in the JSF program. As of October 2008, Italy outlined a requirement for 131 F-35s for the Aeronautica Militare and Marina Militare. Present plans schedule the acquisition of 69 F-35As and 62 F-35Bs. Italian Navy will get 22 F-35Bs while the Air Force will get 69 F-35A and 40 F-35B STOVL version aircraft. The Navy plans to use the F-35Bs on the new Cavour STOVL carrier.

Alenia Aeronautica will be the second source supplier of the wing box. Under the terms of agreement Alenia Aeronautica is slated to produce more than 1,200 wings for the F-35 for the nine partners, United States, United Kingdom, Netherlands, Turkey, Australia, Canada, Denmark and Norway. Other participation in the program include work on the electro-optical targeting system, on the electronic-warfare suite, ejection seat, radio, 25 mm gun and DAS systems, performed by the Finmeccanica's companies. Avio is participating in both the Pratt & Whitney F135 and General Electric/Rolls-Royce F136 powerplant programs.

On 7 October 2008, Italy announced it will not participate in initial F-35 testing and evaluation, and will not purchase test aircraft.

Italy's Air Base of Cameri will be the only Final Assembly and Check Out/Maintenance, Repair, Overhaul & Upgrade (FACO/MRO&U) facility outside the US, for the final assembly of F-35s to be delivered to Italy and the Netherlands, with an estimated cost of $775 million. The FACO could also operate as a regional maintenance and support center within the F-35 logistics solution.

Netherlands

The Netherlands has plans to acquire 85 F-35As for the Royal Netherlands Air Force. The aircraft will replace an aging fleet of Lockheed Martin F-16AM. The Dutch government expects the costs to be €5.5 billion for the initial purchase and €9.1 billion for 30 years of service; which comes down to a lifetime cost of about 215 Million US$ per unit. On 19 November 2007, in the Dutch Parliament, the Secretary of Defence was questioned about the JSF delay, technical problems and rising costs. However, on 29 February 2008, the executive council of the Dutch government decided to go ahead with the purchase of two test aircraft and a MOU was signed. On 7 September 2008 Dutch television show "Reporter" reports that counter orders are lagging behind compared to promises and that an active lobby by the Royal Netherlands Air Force has manipulated the Dutch government into participating in the project.

The Dutch parliament has voted to cancel its order for the first test series. Because there is only a caretaker government at the moment, Defence Minister Van Middelkoop stated he can and will not honour the wishes of the parliament.

Canada

Canada has been involved in the Joint Strike Fighter Program from its beginning, investing US$10 million to be an "informed partner" during the evaluation process. Once Lockheed Martin was selected as the primary contractor for the JSF program, Canada elected to become a level 3 participant along with Norway, Denmark, Turkey, and Australia on the JSF project. An additional US$100 million from the Canadian Department of National Defence (DND) over 10 years and another $50 million from Industry Canada were dedicated in 2002, making them an early participant of the JSF program.

Alan S. Williams of Queen's University has indicated that he believes that Canada's rationale for joining the JSF project was not due to an urgent need to replace Canada's fleet of CF-18 Hornets; instead, it was driven primarily by economics. Through Canadian government investment in the JSF project, Williams says that Canadian companies were allowed to compete for contracts within the JSF project, as there were fears that being shut out from industrial participation in such a large program would severely damage the Canadian aviation industry. Joining also furthered Canadian access to information regarding the F-35 as a possible contender when it eventually plans to replace the CF-18 Hornet fleet. Improved interoperability with major allies allowed the DND to gain insight on leading edge practices in composites, manufacturing and logistics, and offered the ability to recoup some investment if the government did decide to purchase the F-35.

As a result of the Canadian government investment in the JSF project, 144 contracts were awarded to Canadian companies, universities, and government facilities. Financially, the contracts are valued at US$490 million for the period 2002 to 2012, with an expected value of US$1.1 billion from current contracts in the period between 2013 and 2023, and a total potential estimated value of Canadian JSF involvement from US$4.8 billion to US$6.8 billion.

On 16 July 2010, the Canadian government announced that it would buy 65 F-35s to replace the existing 80 CF-18s for $16B (with all ancillary costs included) starting in 2016. Opposition Liberal Party Leader Michael Ignatieff immediately called for the House of Commons Defence Committee to reconvene as soon as possible and examine the purchase, calling it a "secretive, unaccountable decision to proceed with this contract." Ignatieff has claimed they would put the sole-sourced contract on hold should they form the next government. The purchase announcement has created Canadian media speculation that, with the national opposition parties uniting against the sole-source contract, this contract may bring down the minority Conservative government and force an election over the issue. The media have criticized the aircraft as being too expensive, too short-ranged, and too complex for Canada's needs.

There has also been much support for the program. MGen Tom Lawson, Assistant Chief of the Air Staff, has said that the stealth of the F-35 could be helpful in defending Canada's sovereignty as Russian bombers would be faced with an undetectable threshold. Many members of the opposition Liberal party, such as retired general Romeo Dallaire and former Quebec Liberal MP Jacques Saada have sided with the Conservative government's purchase of the F-35s. Dallaire has referred to the F-35 as an "excellent" fighter and has suggested Canada should actually purchase more than the contracted 65, while Saada, the current head of Quebec's Aerospace Association (AQA), claimed the contract was the culmination of a "very serious" competitive bidding process in the late 1990s - countering the claims of the two opposition parties.

Canadian Wikipedia controversy

On 28 July 2010 the National Post newspaper reported that IP addresses registered to the Canadian Department of National Defence Defence Research Establishment Ottawa had been used on 20 and 21 July to try to remove text critical of the Canadian government's F-35 purchase from the Wikipedia article on the aircraft. Repeated attempts to remove the text and add insults to the opposition were made by three IP addresses at the establishment. Martin Champoux, DRDC Manager of Public Affairs indicated it was not part of a government campaign to eliminate criticism, stating, "It sounds to me like someone was freelancing. This is not behaviour we commonly condone." Champoux indicated organization IT specialists are attempting to track down the people responsible and that employees will be reminded about government regulations regarding personal computer use. On 31 July 2010 The Ottawa Citizen reported that the IP addresses responsible had been traced to CFB Cold Lake.

Official Opposition leader Michael Ignatieff stated on 29 July 2010 that the Wikipedia incidents show the government has "something to hide". He added, "Instead of making the case for Canadians ... saying, 'this is why we need this plane,' they're playing these games with Wikipedia. If you can't prove this case straight up and you have to resort to these tricks, then there's something wrong with the very proposition."

New Democratic Party Leader Jack Layton publicly said on 29 July 2010, "Attempting to expunge the realities of debate. I mean what the heck is going on here? We all knew [Prime Minister Stephen] Harper operated a controlling operation, but we didn't think he was willing to go so far as to snatch the words out of people's mouths and pretend they never were spoken. I hope that DND are simply disavowing this practice and will put a stop to it ASAP."

Turkey

On 12 July 2002, Turkey became the seventh international partner in the JSF Project, joining the United Kingdom, Italy, the Netherlands, Canada, Denmark and Norway. On 25 January 2007, Turkey signed a memorandum of understanding (MoU) for involvement in F-35 production. The Turkish Air Force is planning to initially order 116 F-35A "CTOL/Air Force versions" at a reported cost of $11 billion. In October 2009, Murad Bayar, head of the Undersecretariat for Defense Industries, has said that Turkey may increase its order to 120 aircraft instead of purchasing Eurofighter Typhoons.

The F-35 will be produced under license in Turkey by Turkish Aerospace Industries (TAI). TAI is one of the two international suppliers to Northrop Grumman (the other being Terma in Denmark). A Letter of Intent (LOI) was signed between TAI and Northrop Grumman ISS (NGISS) International on 6 February 2007. With the LOI, TAI became the second source for the F-35 center fuselage. The number of center fuselages to be produced by TAI will depend on the number of F-35s Turkey procures and the number of F-35s produced worldwide. On 10 December 2007, TAI was authorized by Northrop Grumman to commence fabricating subassemblies for the first two F-35 production aircraft. The subassemblies – composite components and aircraft access doors – are used in the F-35 center fuselage, a major section of the aircraft being produced by Northrop Grumman, a principal member of the Lockheed Martin-led F-35 global industry team.

Northrop Grumman currently produces all F-35 center fuselages at its F-35 assembly facility in Palmdale, California. After 2013, TAI will produce 100% of the F-35 under license from Lockheed Martin Corporation, as was the case with the F-16 Fighting Falcon program Peace Onyx I and II. In the future, Turkey intends to incorporate several Turkish designed and manufactured electronic systems into the F-35 platform.

Australia

Australia's then-Minister for Defence Dr. Brendan Nelson signing the JSF Production, Sustainment and Follow-on Development Memorandum of Understanding in December 2006

Australia is participating in the F-35's development, and is expected that overall, 72 or more F-35As will be ordered to replace the Royal Australian Air Force's (RAAF's) F/A-18 Hornet aircraft. The Australian Government announced that it would buy into the F-35's development on 22 June 2002. This decision ended the competition to replace Australia's F/A-18 and F-111 aircraft before it formally began, with other aircraft manufacturers being advised that it would not be worth submitting proposals. The Government argued that joining the F-35 program at an early stage would allow Australia to influence the F-35's development, provide the Government with information on the aircraft's suitability, and generate savings of over $600 million if an order for F-35s is eventually placed. Australia formally signed up to the F-35 Systems Development and Demonstration phase as a Level 3 participant on 30 October 2002.

In November 2006, satisfied with the F-35's progress to date, the Government gave 'first pass' initial approval to the project under which F-35s will be acquired, with a decision on whether to order the aircraft being scheduled for late 2008. Following this initial approval, on 13 December 2006 Australia signed the JSF Production, Sustainment and Follow-on Development Memorandum of Understanding which commits Australia to the next phase of the F-35's development. In October 2006, the deputy chief of the Air Force, Air Vice Marshal John Blackburn, publicly stated that the RAAF had considered suitable aircraft which could be acquired if the F-35 was delayed, but that such aircraft were not believed to be necessary on the basis of the F-35 program's progress at the time. Concerns over the F-35s delivery schedule developed in Australia during 2007. In February the Minister for Defence announced that a risk mitigation strategy which involved obtaining F/A-18F Hornets was being developed to prevent a gap in the RAAF's air combat capability if the F-35 program was delayed. This strategy was adopted, and an order for 24 F/A-18Fs was announced on 6 March 2007. These aircraft are scheduled to enter service with the RAAF in 2010 and be fully operational by 2012.

Following the 2007 Australian Federal Election, the new Australian Labor Party Government launched an inquiry into the replacement of the RAAF's air combat capability. The party had expressed concerns over the F-35's adequacy while it was in opposition, and proposed acquiring F-22s to replace or supplement the RAAF's F-35 force. An approach was made to the U.S. Government for F-22s in early 2008, but was not successful as these aircraft are not available for export. In April 2008 it was reported that the air combat review had found that the F-35 was the most suitable aircraft for Australia. In October 2008 it was reported that the Australian Government may order 75 F-35s instead of the 100 originally (and still officially) planned, due to the impact of the global financial crisis and a large long-term funding gap in the Defence budget. The Government's Defence white paper released in April 2009 argued for a purchase of up to 100 F-35s, however.

There has been much debate in Australia over whether the F-35 is the most suitable aircraft for the RAAF. It has been claimed that the F-35's performance is inferior to Russian-built fighters operated by countries near Australia (such as the Su-27 and Su-30 in Indonesia), that it cannot meet the RAAF's long-range strike requirement, and that further delays to the F-35 program may result in the RAAF experiencing a shortage of combat aircraft. The RAAF has stated that it believes that the F-35 will meet Australia's needs, and both of Australia's major political parties currently support the development and purchase of the aircraft (though differences remain on the deadline and the number of aircraft).

On 21 August 2009, it was reported that the RAAF would get two F-35s for testing in 2014 and that the initial squadron would be delayed until 2017. On 11 September 2009, Air Marshall Mark Binskin said that a fourth squadron of F-35s for the RAAF would be imperative. On 25 November 2009, Australia committed to placing a first order for 14 aircraft at a cost of AUD3.2 billion with deliveries to begin in 2014.

Norway

Norway participates in the F-35 program as a Level 3 partner in the System Development and Demonstration phase with a view to enabling its industry to compete for industrial opportunities. Norwegian National Deputy Rune Fagerli, the country's sole representative on the Joint Strike Fighter program, told SPACE.com the Norwegian Royal Ministry of Defence has pledged $125 million in preparations to replace a fleet of F-16 jets that have about 12 years left of operation. "By getting involved here, on the ground level, we can try and address the needs of Norway into this capable fighter early," said Fagerli, a colonel. In Norway, F-16s are fitted with drag chutes because of wet, slippery runways. International cooperation to aircraft development could also yield aircraft from cooperating nations that fit well together during combat. Fagerli also mentioned that Norwegian pilots currently fly missions over Afghanistan in F-16s alongside Danish and Dutch aviators.

Norway has several times threatened to put their support on hold unless substantial guarantees for an increased industrial share is provided. Despite this Norway has signed all the Memoranda of Understanding, including the latest one detailing the future production phase of the JSF program. They have, however, indicated that they will increase and strengthen their cooperation with both competitors of the JSF, the Typhoon and the Gripen.

The F-35 was evaluated along with JAS 39 Gripen by the Norwegian Future Combat Aircraft Capability Project as a replacement for the F-16s currently in-service. On 20 November 2008, the government released a statement saying it will support buying F-35s for the Royal Norwegian Air Force instead of the Gripen NG.

The Norwegian Air Force has decided to develop the Joint Strike Missile for the F-35 and other aircraft.

Denmark

Denmark has joined the Joint Strike Fighter program as a Level 3 partner and the Royal Danish Air Force is considering the replacement of 48 of its aging F-16 fighters with next generation aircraft.

Denmark's MPs are not expected to vote on a purchase of the F-35 before 2012, and are considering alternatives such as the JAS 39 Gripen, F/A-18E/F Super Hornet, and Eurofighter.

Security Cooperative Participants (SCP)

Israel

In 2003, Israel signed a formal letter of agreement, worth almost $20 million, to join the System Development and Demonstration (SDD) effort for the F-35 as a "security cooperation participant" (SCP). The Israeli Air Force (IAF) stated in 2006 that the F-35 is a key part of IAF's recapitalization plans, and that Israel intends to buy over 100 F-35A fighters at an estimated cost of over $5 billion to replace their F-16s over time. Israel was reinstated as a partner in the development of the F-35 on 31 July 2006, after Israeli participation was put on hold following the Chinese arms deal crisis.

On 16 November 2006, Yaakov Katz, of The Jerusalem Post reported that if no jet fighters were delivered to Israel between the last batch of F-16s in 2007 and the first F-35s in 2014 then the Israeli air force would decline in numbers as older fighters wore out and were retired.

On 3 September 2007, IDF Chief of General Staff Lt.-Gen. Gabi Ashkenazi announced the purchase of a squadron of F-35s which Israel will begin receiving in 2014. However, U.S. defense officials later agreed to allow Israel to receive the fighters as early as 2012. The price of each F-35 is expected to reach $70–80 million.

The Jerusalem Post reported in 2008 that the Pentagon has agreed to supply the F-35A variant to Israel as early as 2012, instead of in 2014 or 2015. This would make Israel one of the first nations to receive the aircraft, and very possibly the first foreign nation. Previous objections to Israel’s installation of its own technology in the F-35 – as it has done with every US fighter it has received – were also reportedly overcome. At present, the only Israeli technology in the standard version will be the JSF HMDS helmet-mounted display system, designed in cooperation with Elbit Systems. Israel also asked to manufacture F-35 aircraft locally at a 1:2 ratio, but the reports did not indicate whether that request was granted. On 30 September 2008, the US DoD reported that Israel has requested to purchase 25 F-35As with options to buy up to 50 F-35As or F-35Bs.

On 24 June 2009, The Jerusalem Post reported that an understanding had been reached on "the main basic issues". These include Israeli electronics and the ability to maintain the aircraft independently and that deliveries could start as early as 2014. On 8 September 2009, The Jerusalem Post reported that negotiations had bogged down again over Israeli insistence that they be given sufficient technical details to enable them to equip the aircraft with their own technologies and repair them independently. On 4 November 2009, it reported that a likely failure to sign a contract for 25 aircraft by the start of 2010 would delay the deliveries one or two years past the 2014 target date.

Haaretz has reported disaffection by Israeli defense firms over what will be their minimal contributions to "the largest procurement program in IDF history." A contract was to be signed in March 2010, but is to be put off until spring 2011 due to F-35 flight testing delays.

Israel continues to have issues with having to depend on the global F-35 support chain and the inability to install Israel specific electronic warfare systems.

Rafael Advanced Defense Systems is developing smaller versions of the Python (missile) and Derby for internal carriage while Israel Military Industries is developing a penetration bomb in the same configuration as the Mk 82 500 lb bomb. However these have been put off in order to rush the aircraft into operation to deal with the Nuclear program of Iran.

In 2010 Israel added the additional condition for a US-run logistics and maintenance center in Israel and the United States refused to provide Israel with a specially modified experimental F-35 that could be flown to develop Israeli modifications.

On 26 July 2010, Israeli Defense Minister Ehud Barak said that he would insist on the industrial participation, local electronic warfare parts and local weapons aspects during his trip to the United States.

Singapore

In February 2003, Singapore joined the JSF program's System Design and Development (SDD) Phase, as a Security Co-operation Participant (SCP). Singapore could be buying up to 100 F-35s.

Potential exports

The F-35 is a possible future offer to the Indian Air Force as of July 2007. This has been interpreted as part of a tactic to sell the F-16 as a multirole fighter to the IAF, as part of its competition to acquire 126 new fighters. Lockheed Martin formally expressed its interest to sell F-35s to India. It is also known that the Indian Navy has shown interest in buying the F-35B. Lockheed Martin has offered ‘B’and ‘C’ versions of the F-35 fighters aircraft to meet Indian Navy’s requirements for carrier-based combat aircraft.

The Brazilian Air Force recently has added the F-35 Joint Strike Fighter to the list of aircraft under consideration for its relaunched new fighter procurement, called F-X2. The F-35 replaces the F-16, which was in contention for the previous F-X BR program, shelved in 2003 and finally abandoned in 2006. Lockheed Martin did not offer the F-35 and instead bid the F-16BR in 2008.

The Finnish Air Force has expressed its interest in the F-35, and other "advanced aircraft", as the replacement for its F-18C Hornets. An eventual purchase decision would be taken around 2015.

The future Spanish Navy ship Juan Carlos I (L61) is adapted to carry JSF and AV-8B Harrier.

Lockheed Martin is offering the F-35 to Greece's Hellenic Air Force as a replacement for F-4E Peace Icarus 2000 and F-16C/D Block 30 aircraft.

Taiwan has requested to buy the F-35 from the US. However this has been rejected by the US in fear of a critical response from China. In March 2009 Taiwan again was looking to buy U.S. fifth-generation fighter jets featuring stealth and vertical takeoff capabilities.

The United States has asked Japan for a billion yen for basic information about the F-35 and is only willing to disclose information about the F-35's stealth features after Japan commits to the purchase. The Japanese Defense Ministry did not include a request for the fighter in its 2011 budget, but it has strong support in the Japan Air Self-Defense Force.

South Korea is considering the F-35 amongst several other competitors for the third stage of its F-X program.

The United Arab Emirates has requested information about a possible sale of F-35s, however the United States has delayed for months on the response.

Variants

The F-35 is planned to be built in three different versions to suit the needs of its various users.

F-35A

F-35 Lightning II over Eglin Air Force Base

The F-35A is the conventional takeoff and landing (CTOL) variant intended for the US Air Force and other air forces. It is the smallest, lightest F-35 version and is the only variant equipped with an internal cannon, the GAU-22/A. This 25 mm cannon is a development of the GAU-12 carried by the USMC's AV-8B Harrier II. It is designed for increased effectiveness compared to the 20 mm M61 Vulcan cannon carried by other USAF fighters.

The F-35A is expected to match the F-16 in maneuverability and instantaneous and sustained high-g performance, and outperform it in stealth, payload, range on internal fuel, avionics, operational effectiveness, supportability, and survivability. It also has an internal laser designator and infrared sensors, equivalent to the Sniper XR pod carried by the F-16, but built in to remain stealthy.

The A variant is primarily intended to replace the USAF's F-16 Fighting Falcon, beginning in 2013, and replace the A-10 Thunderbolt II starting in 2028.

F-35B

The F135 engine with lift fan, roll posts, and rear vectoring nozzle, as designed for the F-35B, at the Paris Air Show, 2007

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 some fuel volume to make room for the vertical flight system. Takeoffs and landing with vertical flight systems are by far the riskiest, and in the end, a decisive factor in design. Like the AV-8B Harrier II, the B's guns will be carried in a ventral pod. Whereas F-35A is stressed to 9 g, the F-35B is stressed to 7 g. Unlike the other variants, the F-35B has no landing hook; the "STOVL/HOOK" button in the cockpit initiates conversion instead of dropping the hook.

The United Kingdom's Royal Air Force and Royal Navy plan to use this variant to replace their Harrier GR7/GR9s. The United States Marine Corps intends to purchase 340 F-35Bs to replace all current inventories of the F/A-18 Hornet (A, B, C and D-models), and AV-8B Harrier II in the fighter, and attack roles. The USMC is investigating an electronic warfare role for the F-35B to replace the service's EA-6B Prowlers.

One of the British requirements was that the F-35B design should have a Ship-borne Rolling and Vertical Landing (SRVL) mode so that wing lift could be added to powered lift to increase the maximum landing weight of carried weapons. This method of landing is slower than wire arrested landing, and could disrupt regular carrier operations. The UK are developing a SRVL method to operate F-35Bs from carriers without disrupting carrier operations landings as the landing method uses the same pattern of approach as wire arrested. With SRVL, the aircraft is able to "bring back" 2 x 1K JDAM, 2 x AIM-120 and reserve fuel.

The F-35B was unveiled at Lockheed Martin's Fort Worth plant on 18 December 2007, and the first test flight was on 11 June 2008. The B variant is expected to be available beginning in 2012.

F-35C

The F-35C carrier variant has a larger, folding wing and larger control surfaces for improved low-speed control, and stronger landing gear and hook for the stresses of carrier landings. The larger wing area allows for decreased landing speed, increased range and payload, with twice the range on internal fuel compared with the F/A-18C Hornet, achieving much the same goal as the heavier F/A-18E/F Super Hornet.

The United States Navy will be the sole user for the carrier variant. It intends to buy 480 F-35Cs to replace the F/A-18A, B, C, and D Hornets. The F-35C will also serve as a stealthier complement to the Super Hornet. On 27 June 2007, the carrier variant completed its Air System Critical Design Review (CDR). This allows the first two functional prototype F-35C units to be produced. The C variant is expected to be available beginning in 2014. The first production F-35C was rolled out on 29 July 2009.

Specifications (F-35A)

The first of 15 pre-production F-35s

F-35A and F-35C armament

F-35B cutaway with LiftFan

External image
F-35B Lightning II cutaway illustration
Hi-res cutaway of F-35B Lightning II STOVL by Flight Global, 2006.

Data from Lockheed Martin specifications, F-35 Program brief, F-35 JSF Statistics

General characteristics

• Crew: 1Internal fuel: 18,480 lb (8,382 kg)

Performance

• Thrust/weight:
  
  • With full fuel: 0.80
  • With 50% fuel: 0.97
• g-Limits: 9 g

Armament

• Guns: 1 × 25 mm (0.984 in) GAU-22/A cannon, internally mounted with 180 rounds
• Hardpoints: 6× external pylons on wings with a capacity of 15,000 lb (6,800 kg) and 2 × internal bays with 2 pylons each for a total weapons payload of 18,000 lb (8,100 kg), with provisions to carry combinations of:
  • Missiles:
    
    • Air-to-air: AIM-120 AMRAAM, AIM-132 ASRAAM, AIM-9X Sidewinder, IRIS-T, Joint Dual Role Air Dominance Missile (JDRADM) (after 2020)
    • Air-to-ground: AGM-154 JSOW, AGM-158 JASSM
  • Bombs: ***Mark 84, Mark 83 and Mark 82 GP bombs
    • Mk.20 Rockeye II cluster bomb
    • Wind Corrected Munitions Dispenser capable
    • Paveway-series laser-guided bombs
    • Small Diameter Bomb (SDB)
    • JDAM-series
    • B61 nuclear bomb (for F-35A in 2017)

Avionics

• Northrop Grumman Electronic Systems AN/APG-81 AESA radar

Differences across variants

Differences between variants

	F-35A CTOL	F-35B VSTOL	F-35C Carrier version
Length	51.4 ft (15.7 m)	51.3 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)
Wing Area	460 ft² (42.7 m²)	460 ft² (42.7 m²)	668 ft² (62.1 m²)
Empty weight	29,300 lb (13,300 kg)	32,000 lb (14,500 kg)	34,800 lb (15,800 kg)
Max takeoff weight	70,000 lb (31,800 kg)	60,000 lb (27,000 kg)	70,000 lb (31,800 kg)
Range	1,200 nmi (2,220 km)	900 nmi (1,670 km)	1,400 nmi (2,520 km)
Combat radius	610 nmi (1,100 km)	500 nmi (910 km);	640 nmi (1,150 km)
Thrust/weight full fuel 50% fuel	0.80 0.97	0.88 1.02	0.75 0.91

Media

• X-35 video with transition to VTOL configuration, hover, take off in STOVL configuration, in-flight re-fuelling, vertical hover and landing.
• Test firing of F-35 gun.
• Vertical landing

External images
Official JSF program videos "Official Lockheed Martin F-35 videos."

See also

Related development

• Lockheed Martin X-35
• F-22 Raptor

Aircraft of comparable role, configuration, and era

• Sukhoi PAK FA

Related lists

• List of fighter aircraft
• List of active United States military aircraft
• List of Aerospace megaprojects

References

Notes

Citations

Bibliography

• Borgu, Aldo. A Big Deal: Australia's Future Air Combat Capability. Canberra: Australian Strategic Policy Institute, 2004. ISBN 1-92072-225-4.
• Gunston, Bill. Yakovlev Aircraft since 1924. London: Putnam Aeronautical Books, 1997. ISBN 1-55750-978-6.
• Keijsper, Gerald. Lockheed F-35 Joint Strike Fighter. London: Pen & Sword Aviation, 2007. ISBN 978-1-84415-631-3.
• Kopp, Carlo and Peter Goon. "Joint Strike Fighter." Air Power Australia. Retrieved: 15 July 2007.
• Spick, Mike. The Illustrated Directory of Fighters. London: Salamander, 2002. ISBN 1-84065-384-1.
• Winchester, Jim. "Lockheed Martin X-35/F-35 JSF." Concept Aircraft: Prototypes, X-Planes and Experimental Aircraft. Kent, UK: Grange Books plc., 2005. ISBN 1-59223-480-1.

External links

• Official JSF web site
• Official Team JSF industry web site
• JSF UK Team
• F-35 - Royal Air Force
• US Navy Research, Development & Acquisition, F-35 page
• F-35 - Global Security
• F-35 profile and F-35 weapons carriage on Aerospaceweb.org
• F-35 Lightning II News on f-35jsf.net
• F-35B Roll out pictures
• F-35 Article - Armed Forces