F-35 Lightning II
Encyclopedia
The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, fifth generation
Fifth generation jet fighter
A fifth-generation jet fighter is a fighter aircraft classification used in the United States encompassing the most advanced generation of fighter aircraft...

 multirole fighters
Multirole combat aircraft
A multirole combat aircraft is an aircraft designed to act in at least two different roles in combat. The primary role is usually a fighter—hence, it is as often called a multirole fighter—while the secondary role is usually air-to-surface attack. More roles are added, such as air reconnaissance,...

 under development to perform ground attack, reconnaissance
Reconnaissance
Reconnaissance is the military term for exploring beyond the area occupied by friendly forces to gain information about enemy forces or features of the environment....

, and air defense
Aerial warfare
Aerial warfare is the use of military aircraft and other flying machines in warfare, including military airlift of cargo to further the national interests as was demonstrated in the Berlin Airlift...

 missions with stealth
Stealth aircraft
Stealth aircraft are aircraft that use stealth technology to avoid detection by employing a combination of features to interfere with radar as well as reduce visibility in the infrared, visual, audio, and radio frequency spectrum. Development of stealth technology likely began in Germany during...

 capability. The F-35 has three main models; one is a conventional takeoff and landing
CTOL
CTOL is an acronym for conventional take-off and landing, and is the process whereby conventional aircraft take off and land, involving the use of runways. The aircraft will taxi along the runway until its rotation speed is reached, then climb into the air...

 variant, the second is a short take off and vertical-landing
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

 variant, and the third is a carrier-based
Carrier-based aircraft
Carrier-based aircraft are military aircraft designed specifically for operations from aircraft carriers. The term is generally applied only to fixed-wing aircraft, as naval helicopters are able to operate from a wider variety of aviation-capable ships. Carrier-based aircraft must be relatively...

 variant.

The F-35 is descended from the X-35
Lockheed Martin X-35
The Lockheed Martin X-35 was an experimental aircraft developed by Lockheed Martin for the Joint Strike Fighter Program. It was declared the winner over the Boeing X-32 and went on to enter production in the early 21st century as the F-35 Lightning II....

, the product of the Joint Strike Fighter
Joint Strike Fighter Program
Joint Strike Fighter is a development and acquisition program intended to replace a wide range of existing fighter, strike, and ground attack aircraft for the United States, the United Kingdom, Canada, and their allies. After a competition between the Boeing X-32 and the Lockheed Martin X-35, a...

 (JSF) program. JSF development is being principally funded by the United States, with the United Kingdom and other partner governments providing additional funding. The partner nations are either NATO members or close U.S. allies. It is being designed and built by an aerospace industry team led by Lockheed Martin
Lockheed Martin
Lockheed Martin is an American global aerospace, defense, security, and advanced technology company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area....

. The F-35 took its first flight
Maiden flight
The maiden flight of an aircraft is the first occasion on which an aircraft leaves the ground of its own accord. This is similar to a ship's maiden voyage....

 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 United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 (USAF) budget data in 2010, along with other sources, projects the F-35 to have a flyaway cost
Flyaway cost
Flyaway cost is one measure of the cost of an aircraft. It values the aircraft at its marginal cost, including only the cost of production and production tools immediately accruing to the building of a single unit...

 from US$89 million to US$200 million over the planned production of F-35s. Cost estimates have risen to $382 billion for 2,443 aircraft, at an average of $156 million each. The rising program cost estimates have cast doubt on the actual number to be produced for the U.S. In January 2011, the F-35B variant was placed on "probation" for two years because of development problems. In February 2011, the Pentagon put a price of $207.6 million for each of the 32 aircraft to be acquired in FY2012, rising to $304.15 million ($9,732.8/32) if its share of RDT&E spending is included.

JSF Program requirements and selection

The JSF program was designed to replace the United States military 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 percent of their parts:
  • F-35A, conventional take off and landing (CTOL
    CTOL
    CTOL is an acronym for conventional take-off and landing, and is the process whereby conventional aircraft take off and land, involving the use of runways. The aircraft will taxi along the runway until its rotation speed is reached, then climb into the air...

    ) variant.
  • F-35B, short-take off and vertical-landing (STOVL
    STOVL
    STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

    ) variant.
  • F-35C, carrier-based CATOBAR
    CATOBAR
    CATOBAR is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier...

     (CV) variant.


George Standridge of Lockheed Martin has said that the F-35 will be four times more effective than legacy fighters in air-to-air combat, eight times more effective than legacy fighters in air-to-ground combat, and three times more effective than legacy fighters in reconnaissance and suppression of air defenses – while having better range and requiring less logistics support and having around the same procurement costs (if development costs are ignored) as legacy fighters. Further, the design goals call for the F-35 to be the premier strike aircraft through 2040 and be second only to the F-22 Raptor in air superiority.

While 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
Boeing X-32
The Boeing X-32 was a multi-purpose jet fighter in the Joint Strike Fighter contest. It lost to the Lockheed Martin X-35 demonstrator which was further developed into the F-35 Lightning II.-Background:...

. Although both aircraft met or exceeded requirements, the X-35 design was considered to have less risk and more growth potential. The designation of the new fighter as "F-35" is out-of-sequence with standard DoD aircraft numbering, by which it should have been "F-24". It came as a surprise even to Lockheed, which had been referring to the aircraft in-house by this expected designation.

Design phase

Based on wind tunnel testing, Lockheed Martin slightly enlarged its X-35
Lockheed Martin X-35
The Lockheed Martin X-35 was an experimental aircraft developed by Lockheed Martin for the Joint Strike Fighter Program. It was declared the winner over the Boeing X-32 and went on to enter production in the early 21st century as the F-35 Lightning II....

 design into the F-35. The forward fuselage is 5 inches (127 mm) longer to make room for avionics. Correspondingly, the horizontal stabilator
Stabilator
A stabilator is an aircraft control surface that combines the functions of an elevator and a horizontal stabilizer...

s were moved 2 inches (50.8 mm) rearward to retain balance and control. The top surface of the fuselage was raised by 1 inches (25.4 mm) along the center line. 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. Manufacturing of parts for the first F-35 prototype airframe began in November 2003.

The F-35B STOVL variant was in danger of missing performance requirements in 2004 because it weighed too much; reportedly, by 2200 lb (997.9 kg) or 8 percent. In response, Lockheed Martin added engine thrust and thinned airframe members; reduced the size of the common weapons bay and vertical stabilizers; re-routed some thrust from the roll-post outlets to the main nozzle; and redesigned 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 2700 pounds (1,224.7 kg).

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
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

-era twin-prop Lockheed P-38 Lightning and the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

-era jet, the English Electric Lightning
English Electric Lightning
The English Electric Lightning is a supersonic jet fighter aircraft of the Cold War era, noted for its great speed and unpainted natural metal exterior finish. It is the only all-British Mach 2 fighter aircraft. The aircraft was renowned for its capabilities as an interceptor; Royal Air Force ...

. English Electric Company's aircraft division was a predecessor of F-35 partner BAE Systems
BAE Systems
BAE Systems plc is a British multinational defence, security and aerospace company headquartered in London, United Kingdom, that has global interests, particularly in North America through its subsidiary BAE Systems Inc. BAE is among the world's largest military contractors; in 2009 it was the...

. Lightning II was also an early company name for its fighter that was later named 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.

Lockheed Martin Aeronautics
Lockheed Martin Aeronautics
Lockheed Martin Aeronautics Company is a major unit of Lockheed Martin with headquarters at Fort Worth, Texas.Lockheed Martin Aeronautics is also based in Marietta, Georgia and Palmdale, California. Palmdale is home to the Advanced Development Programs , informally known as the "Skunk Works"...

 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
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...

 provides Active Electronically Scanned Array
Active Electronically Scanned Array
An Active Electronically Scanned Array , also known as active phased array radar is a type of phased array radar whose transmitter and receiver functions are composed of numerous small solid-state transmit/receive modules . AESAs aim their "beam" by broadcasting radio energy that interfere...

 (AESA) radar, electro-optical Distributed Aperture System (DAS), Communications, Navigation, Identification (CNI), center fuselage, weapons bay, and arrestor gear. BAE Systems
BAE Systems
BAE Systems plc is a British multinational defence, security and aerospace company headquartered in London, United Kingdom, that has global interests, particularly in North America through its subsidiary BAE Systems Inc. BAE is among the world's largest military contractors; in 2009 it was the...

 provides aft fuselage and empennages, horizontal and vertical tails, crew life support and escape systems, Electronic warfare
Electronic warfare
Electronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum. The purpose of electronic warfare is to deny the opponent the advantage of, and ensure friendly...

 systems, fuel system, and Flight Control Software (FCS1). Alenia
Alenia Aeronautica
Alenia Aeronautica, a Finmeccanica subsidiary, is a European aerospace company from Italy. Its subsidiaries include Alenia Aermacchi and Alenia Aeronavali...

 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. The F-35 program has seen a great deal of investment in automated production facilities. For example, Handling Specialty produced the wing assembly platforms for Lockheed Martin. In November 2009, Jon Schreiber, head of F-35 international affairs program for the Pentagon, said that the U.S. will not share the software code for the F-35 with its allies.

As of 5 January 2009, six F-35s were complete, including AF-1 and AG-1, and 17 were 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 Air Force Base
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....

." On 6 April 2009, US Secretary of Defense Robert Gates
Robert Gates
Dr. Robert Michael Gates is a retired civil servant and university president who served as the 22nd United States Secretary of Defense from 2006 to 2011. Prior to this, Gates served for 26 years in the Central Intelligence Agency and the National Security Council, and under President George H. W....

 proposed speeding up production for the US to buy 2,443 F-35s.

In August 2010, Lockheed Martin announced delays in resolving a "wing-at-mate overlap" production problem, which would slow initial production.

Program cost increases and further delays

On 21 April 2009, media reports, citing Pentagon
The Pentagon
The Pentagon is the headquarters of the United States Department of Defense, located in Arlington County, Virginia. As a symbol of the U.S. military, "the Pentagon" is often used metonymically to refer to the Department of Defense rather than the building itself.Designed by the American architect...

 sources, said that during 2007 and 2008, computer spies had managed to copy and siphon off several terabytes of data related to the F-35's design and 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 the JSF Program Manager, U.S. Marine Corps Major General 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
Government Accountability Office
The Government Accountability Office is the audit, evaluation, and investigative arm of the United States Congress. It is located in the legislative branch of the United States government.-History:...

 to United States Senate Committee on Armed Services
United States Senate Committee on Armed Services
The Committee on Armed Services is a committee of the United States Senate empowered with legislative oversight of the nation's military, including the Department of Defense, military research and development, nuclear energy , benefits for members of the military, the Selective Service System and...

 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, 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. Lockheed Martin expects to reduce government cost estimates by 20%.

In November 2010 as part of a cost-cutting measure, the co-chairs of the National Commission on Fiscal Responsibility and Reform
National Commission on Fiscal Responsibility and Reform
The National Commission on Fiscal Responsibility and Reform is a Presidential Commission created in 2010 by President Barack Obama to identify "…policies to improve the fiscal situation in the medium term and to achieve fiscal sustainability over the long run."...

 suggested canceling procurement of the F-35B and halving orders of F-35As and F-35Cs. At the same time Air Force Magazine reported that "Pentagon officials" are considering canceling the F-35B because its short range means that the bases or ships it operates from will be within range of hostile tactical ballistic missiles. However Lockheed Martin consultant Loren B. Thompson said that this rumor is merely a result of the usual tensions between the US Navy and Marine Corps, and there is no alternative to the F-35B as an AV-8B replacement.
He also confirmed that there would be further delays and cost increases in the development process because of technical problems with the aircraft and software, but blamed most of the delays and extra costs on redundant flight test.

The Center for Defense Information
Center for Defense Information
The Center for Defense Information , founded in 1972 by retired U.S. Navy Rear Admiral Gene La Rocque, states that it is dedicated to strengthening national and international security through international cooperation, reduced reliance on unilateral military power to resolve conflict, reduced...

 estimated that the program would be restructured with an additional year of delay and $5 billion in additional costs. On 5 November 2010, the Block 1 software flew for the first time on BF-4 which included information fusion and initial weapons-release capability. As of the end of 2010, only 15% of the software remains to be written, but this includes the most difficult sections such as data fusion
Data fusion
Data fusion, is generally defined as the use of techniques that combine data from multiple sources and gather that information into discrete, actionable items in order to achieve inferences, which will be more efficient and narrowly tailored than if they were achieved by means of disparate...

. But in 2011 it was revealed that only 50% of the eight million lines of code had actually been written and that it would take another six years and 110 additional software engineers in order to complete the software for this new schedule.

In January 2011 Defense Secretary Robert Gates
Robert Gates
Dr. Robert Michael Gates is a retired civil servant and university president who served as the 22nd United States Secretary of Defense from 2006 to 2011. Prior to this, Gates served for 26 years in the Central Intelligence Agency and the National Security Council, and under President George H. W....

 expressed the Pentagon's frustration with the skyrocketing costs of the F-35 program when he said "The culture of endless money that has taken hold must be replaced by a culture of restraint." Focusing his attention on the troubled VTOL F-35B Gates ordered "a two-year probation", saying it "should be canceled" if corrections are unsuccessful. However, Gates has stated his support for the program. Some private analysts, such as Richard Aboulafia, of the Teal Group state that the whole F-35 program is becoming a money pit.

Former Pentagon manager Paul Kaminski has said that the lack of a complete test plan has added five years to the JSF program. As of February 2011, the main flaws with the aircraft are engine "screech", transonic wing roll-off and display flaws in the helmet mounted display.

The current schedule has the delivery of basic combat capability aircraft in late 2015, followed by full capability block three software in late 2016. The $56.4 billion development project for the aircraft should be completed in 2018 when the block five configuration is expected to be delivered, several years late and considerably over budget.

In November 2010, the GAO found that "Managing an extensive, still-maturing global network of suppliers adds another layer of complexity to producing aircraft efficiently and on-time" and that "However, due to the extensive amount of testing still to be completed, the program could be required to make alterations to its production processes, changes to its supplier base, and costly retrofits to produced and fielded aircraft, if problems are discovered."

Delays in the F-35 program may lead to a "fighter gap" where America and other countries will lack sufficient jet fighters to cover their requirements. Israel may seek to buy second-hand F-15s to cover its gap, while Australia may also seek to buy more American fighters from the USN to cover their own capability gap in the face of F-35 delays.

Initial Operational Capability (IOC) will be determined by software development rather than by hardware production or pilot training.

In May 2011, the Pentagon's top weapons buyer Ashton Carter said that its new $133 million unit price was not affordable.

In 2011 The Economist
The Economist
The Economist is an English-language weekly news and international affairs publication owned by The Economist Newspaper Ltd. and edited in offices in the City of Westminster, London, England. Continuous publication began under founder James Wilson in September 1843...

 warned that the F-35 was in danger of slipping into a "death spiral" where increasing per aircraft costs would lead to cuts in number of aircraft ordered which would lead to further cost increases and further order cuts. Later that year four aircraft were cut from the fifth LRIP order to pay for cost overruns.

This was followed by a contract dispute where the Pentagon insisted that Lockheed Martin help cover the costs of fixes to aircraft already produced. Lockheed Martin also objected to cost sharing in the program because even at this late date the remaining development challenges posed an uninsurable unbounded risk that the company could not cover. However the Senate Armed Services Committee strongly backed the Pentagon position.

Also in 2011 a Congressional Joint Strike Fighter Caucus was formed by some of the top recipients of Lockheed Martin contributions.

Concerns over performance and safety

In 2006 the F-35 was downgraded from "very low observable" to "low observable", a change former RAAF flight test engineer Peter Goon
Air Power Australia
Air Power Australia is a private non-profit Australian think tank. It was formed by Dr Carlo Kopp and Peter Goon in October 2004. The stated primary aim of the organization is 'air power research and analysis, especially in the context of a modern integrated joint national force structure.' Air...

  likened to increasing the radar cross section from a marble to a beach ball.

Andrew Krepinevich
Andrew Krepinevich
Andrew F. Krepinevich, Jr. is a defense policy analyst, currently executive director of the Center for Strategic and Budgetary Assessments. His influential book, The Army and Vietnam, contends that the United States could have won the Vietnam War had the Army adopted a small-unit pacification...

 has questioned the reliance on "short range" aircraft like the F-35 or F-22 to 'manage' China in a future conflict and has suggested reducing the number of F-35s ordered in favor of a longer range platform like the Next-Generation Bomber, but Michael Wynne
Michael Wynne
Michael W. Wynne is an American business executive and was the 21st United States Secretary of the Air Force. Secretary of Defense Robert Gates asked for and received his resignation Michael W. Wynne (born September 4, 1944) is an American business executive and was the 21st United States...

, then United States Secretary of the Air Force
United States Secretary of the Air Force
The Secretary of the Air Force is the Head of the Department of the Air Force, a component organization within the Department of Defense of the United States of America. The Secretary of the Air Force is appointed from civilian life by the President, by and with the advice and consent of the Senate...

 rejected this plan of action in 2007. However in 2011, the Center for Strategic and Budgetary Assessments (CSBA) pointed to the restructuring of the F-35 program and the return of the bomber project as a sign of their effectiveness, while Rebecca Grant
Rebecca Grant (political expert)
Rebecca L. Grant is the Director of the General Billy Mitchell Institute for Airpower Studies at the Air Force Association and a contributing editor for their Air Force Magazine.She is also a senior fellow at the Lexington Institute. She earned her Ph.D...

 said that the restructuring was a "vote of confidence" in the F-35 and "there is no other stealthy, survivable new fighter program out there". Lockheed has also said that the F-35 is designed to launch internally carried bombs at supersonic speed and internal missiles at maximum supersonic speed.

In 2008 it was reported that RAND Corporation conducted simulated war games in which Russian Sukhoi Su-35
Sukhoi Su-35
The Sukhoi Su-35 is a single-seat, twin-engined supermaneuverability multirole fighter. It is a derivative of the Su-27 'Flanker', and was initially known as the Su-27M. More than a dozen of these were built with some used by the Russian Knights aerobatic demonstration team...

 fighters apparently defeated the F-35. As a result of these media reports, then Australian defence minister Joel Fitzgibbon
Joel Fitzgibbon
Joel Andrew Fitzgibbon is an Australian politician and Australian Labor Party member of the Australian House of Representatives since March 1996, representing the Division of Hunter in New South Wales. From December 2007 to June 2009 he was the Minister for Defence in the Rudd Ministry...

 requested a formal briefing from the Australian Department of Defence
Department of Defence (Australia)
The Australian Department of Defence is a Federal Government Department. It forms part of the Australian Defence Organisation along with the Australian Defence Force . The Defence mission is to defend Australia and its national interests...

 on the simulation. This briefing stated that the reports of the simulation were inaccurate and did not actually compare the F-35's flight performance against other aircraft.

The Pentagon and Lockheed Martin added that these simulations did not address air-to-air combat. A Lockheed Martin press-release points to USAF simulations regarding the F-35's air-to-air performance against potential adversaries described as "4th generation" fighters, in which it claims the F-35 is "400 percent" 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 nature of the simulations, and the terms upon which the "400 percent" figure have been derived remains unclear. Regarding the original plan to fit the F-35 with only two air-to-air missiles, Major 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." However the Norwegians have been briefed on a plan to equip the F-35 with six AIM-120D missiles by 2019.

Former RAND author John Stillion has written of the F-35A's air-to-air combat performance that it “can’t turn, can’t climb, can’t run”, but Lockheed Martin test pilot Jon Beesley has countered that in an air-to-air configuration the F-35 has almost as much thrust as weight and a flight control system that allows it to be fully maneuverable even at a 50-degree angle of attack
Angle of attack
Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...

.

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. Lockheed spokesman John Kent has said that the missing fire-suppression systems would have offered "very small" improvements to survivability.

In the context of selling F-35s to Israel to match the F-15s that will be sold to Saudi Arabia, a senior U.S. defense official was quoted as saying that the F-35 will be "the most stealthy, sophisticated and lethal tactical fighter in the sky," and added "Quite simply, the F-15 will be no match for the F-35." After piloting the aircraft, RAF Squadron Leader Steve Long said that, over its existing aircraft, the F-35 will give "the RAF and Navy a quantum leap in airborne capability."

Consultant to Lockheed Martin Loren B. Thompson
Lexington Institute
The Lexington Institute is a non-profit public-policy think tank headquartered in Arlington, Virginia, that focuses on national security, education reform, postal service management, space policy, and U.S...

 has said that the "electronic edge F-35 enjoys over every other tactical aircraft in the world may prove to be more important in future missions than maneuverability".

In 2011, Canadian politicians raised the issue of the safety of the F-35's reliance on a single engine (as opposed to a twin-engine configuration, which provides a backup in case of an engine failure). Canada had previous experience with a high-accident rate with the single-engine Lockheed CF-104 Starfighter with many accidents related to engine failures. Defence Minister Peter MacKay, when asked what would happen if the F-35’s single engine fails in the Far North, stated "It won’t".

Design

The F-35 appears to be a smaller, slightly more conventional, single-engine sibling of the sleeker, twin-engine Lockheed Martin F-22 Raptor, and indeed drew elements from it. The exhaust duct design was inspired by the General Dynamics
General Dynamics
General Dynamics Corporation is a U.S. defense conglomerate formed by mergers and divestitures, and as of 2008 it is the fifth largest defense contractor in the world. Its headquarters are in West Falls Church , unincorporated Fairfax County, Virginia, in the Falls Church area.The company has...

 Model 200 design, which was proposed for a 1972 supersonic VTOL fighter requirement for the Sea Control Ship
Sea Control Ship
The Sea Control Ship was a small aircraft carrier developed and conceptualized by the United States Navy under Chief of Naval Operations Elmo Zumwalt during the 1970s. Currently the term refers to naval vessels that can perform similar duties. The SCS was intended as an escort vessel, providing...

. 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"
Yakovlev Yak-141
The Yakovlev Yak-141 , also known as the Yak-41, is a supersonic vertical takeoff/landing fighter aircraft designed by Yakolev. It did not enter production.-Design and development:...

. 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 stealth fighter.

The F-35 has a maximum speed of over Mach 1.6. With a maximum takeoff weight of 60,000 lb (27,000 kg), the Lightning II is considerably heavier than the lightweight fighters it replaces. In empty and maximum gross weights, it more closely resembles the single-seat, single-engine Republic F-105 Thunderchief, which was the largest single-engine fighter of the Vietnam war
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

 era. However the F-35's modern engine delivers over 60 percent more thrust in an aircraft of the same weight so that in thrust to weight and wing loading it is much closer to a comparably equipped F-16.

Acquisition deputy to the assistant secretary of the Air Force, Lt. Gen. Mark D. "Shack" Shackelford has said that 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
    Stealth technology
    Stealth technology also termed LO technology is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, to make them less visible to radar, infrared, sonar and other detection...

    , 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
    Aviator
    An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...

     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
    Fibre Channel
    Fibre Channel, or FC, is a gigabit-speed network technology primarily used for storage networking. Fibre Channel is standardized in the T11 Technical Committee of the InterNational Committee for Information Technology Standards , an American National Standards Institute –accredited standards...

    .
  • 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.


Lockheed Martin claims the F-35 is intended to have close and long-range air-to-air capability second only to that of the F-22 Raptor. The company has suggested that the F-35 could also replace the USAF's F-15C/D fighters in the air superiority role and the F-15E Strike Eagle in the ground attack role, but it does not have the range or payload of either F-15 model. The F-35A does carry a similar air-to-air armament as the Boeing F-15SE Silent Eagle when both aircraft are configured for low observable operations and has over 80 percent of the larger aircraft's combat radius.

Lockheed Martin has said that the F-35 has the advantage over the F-22 in basing flexibility and "advanced sensors and information fusion".

The majority of the structural composites in the F-35 are made out of bismaleimide (BMI)
Maleimide
Maleimide is the chemical compound with the formula H2C22NH . This unsaturated imide is an important building block in organic synthesis. The name is a contraction of maleic acid and imide, the -CNHC- functional group...

 and composite epoxy material
Composite epoxy material
Composite Epoxy Materials are group of composite materials typically made of woven glass fabric surfaces and non-woven glass core combined with epoxy resin...

. However the F-35 will be the first mass produced aircraft to include structural nanocomposites, Carbon nanotube
Carbon nanotube
Carbon nanotubes are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than for any other material...

 reinforced Epoxy
Epoxy
Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....

.

The F-35 program has learned from the corrosion problems that the F-22 had when it was first introduced in 2005. The F-35 uses a gap filler that causes less galvanic corrosion to the skin, is designed with fewer gaps in its skin that require gap filler, and has better drainage.

A United States Navy study found that the F-35 will cost 30 to 40 percent more to maintain than current jet fighters. And a Pentagon study found that it may cost $1 trillion to maintain the entire fleet over its lifetime.

Engines

The F-35's main engine is the Pratt & Whitney F135
Pratt & Whitney F135
The Pratt & Whitney F135 is an afterburning turbofan developed for the F-35 Lightning II single-engine strike fighter. The F135 family has several distinct variants, including a conventional, forward thrust variant and a multi-cycle STOVL variant that includes a forward lift fan...

. The General Electric/Rolls-Royce F136
General Electric/Rolls-Royce F136
The General Electric/Rolls-Royce F136 is an advanced turbofan engine being developed by General Electric and Rolls-Royce plc for the Lockheed Martin F-35 Lightning II.-Development:...

 has been under development as an alternative engine. The F135/F136 engines are not designed to supercruise
Supercruise
Supercruise is sustained supersonic flight of an aircraft with a useful cargo, passenger, or weapons load performed efficiently and without the use of afterburners ....

 in the F-35. The STOVL versions of both power plants use the Rolls-Royce LiftSystem
Rolls-Royce LiftSystem
The Rolls-Royce LiftSystem is an innovative propulsion system designed for use in the STOVL variant of the F-35 Lightning II developed during the Joint Strike Fighter Program...

, patented by Lockheed Martin and developed and built by Rolls-Royce. This system is more like the Russian Yak-141
Yakovlev Yak-141
The Yakovlev Yak-141 , also known as the Yak-41, is a supersonic vertical takeoff/landing fighter aircraft designed by Yakolev. It did not enter production.-Design and development:...

 and German VJ 101D/E
EWR VJ 101
-See also:-Bibliography:* Rogers, Mike. VTOL: Military Research Aircraft. New York: Orion Books, 1989. ISBN 0-517-57684-8.* Winchester, Jim. "EWR-Sud VJ 101C ". X-Planes and Prototypes. London: Amber Books Ltd., 2005. ISBN 1-904687-40-7....

 than the preceding generation of STOVL designs, such as the Harrier Jump Jet
Harrier Jump Jet
The Harrier, informally referred to as the Jump Jet, is a family of British-designed military jet aircraft capable of vertical/short takeoff and landing operations...

 in which all of the lifting air went through the main fan of the Rolls-Royce Pegasus
Rolls-Royce Pegasus
The Rolls-Royce Pegasus is a turbofan engine originally designed by Bristol Siddeley, and now manufactured by Rolls-Royce plc. This engine is able to direct thrust downwards which can then be swivelled to power a jet aircraft forward. Lightly loaded, it can also manoeuvre like a helicopter,...

 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
Thrust vectoring
Thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine or motor in order to control the attitude or angular velocity of the vehicle....

 nozzle which allows the main engine exhaust to be deflected downward at the tail of the aircraft. The lift fan is near the front of the aircraft and provides a counter-balancing thrust using two counter-rotating blisk
Blisk
A blisk is a single engine component consisting of a rotor disk and blades, which may be either integrally cast, machined from a solid piece of material, or made by welding individual blades to the rotor disk. The term is used mainly in aerospace engine design. The word is a portmanteau of blade...

s. It 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 unheated engine bypass
Bypass duct
A bypass duct is an annular passage that allows some of a turbofan's airflow to bypass the engine core, or gas generator. If the turbofan is unmixed, the bypass duct will terminate at the bypass nozzle...

 air through wing mounted thrust nozzles called Roll Posts. Like lift engines, the added lift fan machinery increases payload capacity during vertical flight, but is dead weight during horizontal 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.

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.

Pratt & Whitney is also testing higher thrust versions of the F135, partly in response to GE's claims that the F136 is capable of producing more thrust than the 43000 lbf (191.3 kN) supplied by early F135s. The F135 has demonstrated a maximum thrust of over 50000 lbf (222.4 kN) during testing. The F-35's Pratt & Whitney F135 is the most powerful engine ever installed in a fighter aircraft.

The F135 is the second (radar) stealthy afterburning jet engine and like the Pratt & Whitney F119
Pratt & Whitney F119
|-See also:-External links:* *...

 from which it was derived, has suffered from pressure pulsations in the afterburner at low altitude and high speed or "screech". In both cases this problem was fixed during development of the fighter program.

Turbine bearing health in the engine will be monitored with thermoelectric powered wireless sensors.

Armament

The F-35A includes a GAU-22/A, a four-barrel version of the GAU-12 Equalizer
GAU-12 Equalizer
The General Dynamics GAU-12/U Equalizer is a five-barrel 25 mm Gatling gun-style rotary cannon. The GAU-12/U is used by the United States, Italy and Spain, which mount the weapon in their fighter jets such as the AV-8B Harrier II, airborne gunships such as the Lockheed AC-130, and land-based...

 25 mm
25 mm caliber
The 25x137 mm caliber/.98425 inch is one of the standard sizes of cannon and autocannon ammunition for NATO forces. The round itself has a length of approximately 223 mm .-Usage:...

 cannon. The cannon is mounted internally with 182 rounds for the F-35A or in an external pod with 220 rounds for 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 electronic warfare equipment, reconnaissance equipment, or possibly a rearward-facing radar.

It has two internal weapons bays, and external hardpoint
Hardpoint
A hardpoint, or weapon station, is any part of an airframe designed to carry an external load. This includes a point on the wing or fuselage of military aircraft where external ordnance, countermeasures, gun pods, targeting pods or drop tanks can be mounted.-Rail launchers:Large missiles and...

s that can mount four underwing pylons and two near wingtip pylons. The two outer hardpoints can only carry pylons for the AIM-9X Sidewinder and AIM-132 ASRAAM
AIM-132 ASRAAM
The AIM-132 Advanced Short Range Air-to-Air Missile is an infrared homing air-to-air missile, produced by MBDA. It is currently in service in the Royal Air Force and Royal Australian Air Force , replacing the AIM-9 Sidewinder...

 air-to-air missiles. The ASRAAMs can be carried on "stealthy" external pylons that add little to the aircraft's radar cross section. The other pylons can carry the AIM-120 AMRAAM
AIM-120 AMRAAM
The AIM-120 Advanced Medium-Range Air-to-Air Missile, or AMRAAM , is a modern beyond-visual-range air-to-air missile capable of all-weather day-and-night operations. Designed with the same form-factor as the previous generation of semi-active guided Sparrow missiles, it is a fire-and-forget...

, Storm Shadow
Storm Shadow
Storm Shadow is a British, French and Italian air-launched cruise missile, manufactured by MBDA. Storm Shadow is the British name for the weapon; in French service it is called SCALP EG...

, AGM-158 Joint Air to Surface Stand-off Missile
AGM-158 JASSM
The AGM-158 JASSM is a low observable standoff cruise missile developed in the United States. It is a large, semi-stealthy long-range weapon of the class. The missile's development began in 1995, but a number of problems during testing delayed its introduction into service until 2009...

 (JASSM) cruise missiles, guided bombs, 480 gallons (1,817 l) and 600 gallons (2,271.2 l) fuel tanks. The external pylons can carry missiles, bombs and fuel tanks at the expense of being more detectable by radar. An air-to-air load of eight AIM-120s and two AIM-9s is possible using internal and external weapons stations; a configuration of six 2000 lb (907.2 kg) bombs, two AIM-120s and two AIM-9s can also be arranged. Internally, up to two 2000 lb (907.2 kg) air-to-ground (BRU-68) bombs can be carried in A and C models (two 1000 lb (453.6 kg) bombs (BRU-67) in the B model,) along with two smaller weapons, normally expected to be air-to-air missiles. The weapon bays can carry AIM-120 AMRAAM, AIM-132 ASRAAM
AIM-132 ASRAAM
The AIM-132 Advanced Short Range Air-to-Air Missile is an infrared homing air-to-air missile, produced by MBDA. It is currently in service in the Royal Air Force and Royal Australian Air Force , replacing the AIM-9 Sidewinder...

, the Joint Direct Attack Munition
Joint Direct Attack Munition
The Joint Direct Attack Munition is a guidance kit that converts unguided bombs, or "dumb bombs" into all-weather "smart" munitions. JDAM-equipped bombs are guided by an integrated inertial guidance system coupled to a Global Positioning System receiver, giving them a published range of up to...

 (JDAM) – up to 2,000 lb (910 kg), the Joint Stand off Weapon
AGM-154 Joint Standoff Weapon
The AGM-154 Joint Standoff Weapon is the product of a joint venture between the United States Navy and Air Force to deploy a standardized medium range precision guided weapon, especially for engagement of defended targets from outside the range of standard anti-aircraft defenses, thereby...

 (JSOW), Brimstone
Brimstone missile
Brimstone is an air-launched anti-tank missile developed by MBDA for Britain's Royal Air Force. It was originally intended for "fire and forget" use against mass formations of enemy armour, using a millimetre wave seeker to ensure accuracy even against moving targets...

 anti-armor missiles, and Cluster Munitions (WCMD). With its payload capability, the F-35 can carry more weapons payload than the legacy fighters it is to replace as well as the F-22 Raptor.

Lockheed Martin states that the weapons load can also be configured as all-air-to-ground or all-air-to-air, and has suggested that a Block 5 version will be able to carry three internal weapons per bay instead of two, replacing the heavy bomb with two smaller weapons such as AIM-120 AMRAAM air-to-air missiles. Upgrades include up to four GBU-39 Small Diameter Bomb
Small Diameter Bomb
The GBU-39 Small Diameter Bomb is a 250 pound guided bomb that is intended to provide aircraft with the ability to carry a higher number of bombs...

s (SDB) in each bay (three per bay in F-35B, or four GBU-53/B
GBU-53/B
The GBU-53/B Small Diameter Bomb II is an American air launched, guided bomb.Development was started in 2006 for a class bomb that can identify and strike mobile targets from standoff distances in all weather conditions. It will be integrated on the F-35 Joint Strike Fighter. Its first flight...

 in each bay for all F-35 variants; The MBDA Meteor
MBDA Meteor
Meteor is an active radar guided beyond-visual-range air-to-air missile being developed by MBDA. It is to equip the Eurofighter Typhoons of the UK's Royal Air Force , Germany's Luftwaffe, Spain's Ejército del Aire and Italy's Aeronautica Militare Italiana, the British and Italian F-35s , the...

 air-to-air missile is currently being adapted to fit four internally in the missile spots and may be integrated into the F-35. A modified Meteor design with smaller tailfins for the F-35 was revealed in September 2010. The United Kingdom 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. The external ASRAAMs will add only an insignificant amount to the F-35's radar cross section and will allow attacks to slightly beyond visual range without using radar that might alert the target. Solid-state lasers were being developed as optional weapons for the F-35 as of 2002.

While the F-35 will take on the Wild Weasel
Wild Weasel
A Wild Weasel is an aircraft specially equipped with radar seeking missiles, and tasked with destroying the radars and SAM installations of enemy air defence systems....

 mission, it will lack the ability to carry an anti-radiation missile internally (and therefore stealthily) until the JDRADM
JDRADM
The Next Generation Missile , formerly the Joint Dual Role Air Dominance Missile , is a proposed Beyond-visual-range air-to-air missile capable of all weather day and night performance....

 is fielded in 2025.

Norway and Australia are funding a program to adapt the Naval Strike Missile
Naval Strike Missile
The Naval Strike Missile is an anti-ship and land-attack missile developed by the Norwegian company Kongsberg Defence & Aerospace , and whose initial serial production contract was signed in June 2007. It has been chosen by the Royal Norwegian Navy for its new Fridtjof Nansen class frigates and...

 (NSM) to fit the internal bays of the F-35. This will be a multi-role version, named the Joint Strike Missile (JSM), and will be the only cruise missile to fit the internal bays. Studies have shown that the F-35 would be able to carry two of these internally, while four additional missiles could be carried externally. The missile has an expected range in excess of 150 nmi (278 km). On 12 April 2011 the Norwegian Ministry of Defense announced phase 2 of development with a cost estimate of 1029 MNOK.

The B61 nuclear bomb
B61 nuclear bomb
The B61 nuclear bomb is the primary thermonuclear weapon in the U.S. Enduring Stockpile following the end of the Cold War. It is an intermediate yield strategic and tactical nuclear weapon featuring a two-stage radiation implosion design....

 was scheduled for deployment in 2017, but delays in the F-35 program may delay this.

Stealth and signatures

The F-35 has been designed to have a low radar cross section
Radar cross section
Radar cross section is a measure of how detectable an object is with a radar. A larger RCS indicates that an object is more easily detected.An object reflects a limited amount of radar energy...

 primarily due to stealthy
Stealth technology
Stealth technology also termed LO technology is a sub-discipline of military tactics and passive electronic countermeasures, which cover a range of techniques used with personnel, aircraft, ships, submarines, and missiles, to make them less visible to radar, infrared, sonar and other detection...

 materials used in construction, including fiber-mat. Unlike the previous generation of fighters, the F-35 was designed with a shape for low-observable characteristics.

The Teen Series
Teen Series
The Teen Series is a popular name for a group of US combat aircraft. The name stems from a series of US supersonic jet fighters built for the United States Air Force and the United States Navy during the late 20th century. The designations system was the 1962 United States Tri-Service aircraft...

 of fighters (F-15, F-16, F/A-18) were notable for always carrying large external fuel tanks, but in order to avoid negating its stealth characteristics the F-35 must fly most missions without external fuel tanks. Unlike the F-16 and F/A-18, the F-35 lacks leading edge extension
Leading edge extension
A leading edge extension is a small extension to an aircraft wing surface, forward of the leading edge. Different kinds of extensions have been used for different reasons.-Leading edge slats:...

s and instead uses stealth-friendly chines for vortex lift in the same fashion as the SR-71 Blackbird
SR-71 Blackbird
The Lockheed SR-71 "Blackbird" was an advanced, long-range, Mach 3+ strategic reconnaissance aircraft. It was developed as a black project from the Lockheed A-12 reconnaissance aircraft in the 1960s by the Lockheed Skunk Works. Clarence "Kelly" Johnson was responsible for many of the...

. The small bumps just forward of the engine air intakes form part of the diverterless supersonic inlet (DSI)
Diverterless supersonic inlet
A diverterless supersonic inlet is a type of jet engine air intake used by some modern combat aircraft to control air flow into their engines. It consists of a "bump" and a forward-swept inlet cowl, which work together to divert boundary layer airflow away from the aircraft's engine while...

 which is a simpler, lighter means to ensure high-quality airflow to the engine over a wide range of conditions. These inlets also crucially improve the aircraft's low-observable characteristics.

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. The F-22 was designed to be difficult to detect by all types of radars and from all directions. The F-35 on the other hand manifests its lowest radar signature from the frontal aspect because of compromises in design. Its surfaces are shaped to best defeat radars operating in the X and upper S band, which are typically found in fighters, surface-to-air missiles and their tracking radars, although the aircraft would be easier to detect using other radar frequencies. Because the shape of the aircraft is so important to its radar cross section, special care must be taken to maintain the "outer mold line" during production. Ground crews require Repair Verification Radar (RVR) test sets in order to verify the RCS of the aircraft after performing repairs, which was not a concern for previous generations of non-stealth fighters.

Low observable aircraft must consider different types of detection and so the F-35 is not only radar stealthy, but it also has infrared and visual signature reduction incorporated.

In late 2008 the Air Force revealed that the F-35 would be about twice as loud at takeoff as the McDonnell Douglas F-15 Eagle and up to four times as loud during landing. As a result, residents near Luke Air Force Base
Luke Air Force Base
Luke Air Force Base is a United States Air Force base located seven miles west of the central business district of Glendale, in Maricopa County, Arizona, United States. It is also about west of Phoenix, Arizona....

, Arizona and Eglin Air Force Base
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....

, Florida, possible home bases for the jet, requested that the Air Force conduct environmental impact studies concerning the F-35's noise levels. The city of Valparaiso
Valparaiso, Florida
Valparaiso is a city in Okaloosa County, Florida, in the United States, and it is named after the Chilean city of Valparaiso. As of the 2000 census, the city population was 6,408. According to the U.S. Census Bureau's 2004 estimates, the city had a population of 6,336...

, 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
Royal Australian Air Force
The Royal Australian Air Force is the air force branch of the Australian Defence Force. The RAAF was formed in March 1921. It continues the traditions of the Australian Flying Corps , which was formed on 22 October 1912. The RAAF has taken part in many of the 20th century's major conflicts...

 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." However according to an acoustics study done by Lockheed Martin and the US Air Force, the noise levels of the F-35 are found to be comparable to the F-22 Raptor and F/A-18E/F Super Hornet.

Cockpit

The F-35 features a full-panel-width "panoramic cockpit display" (PCD) glass cockpit
Glass cockpit
A glass cockpit is an aircraft cockpit that features electronic instrument displays, typically large LCD screens, as opposed to the traditional style of analog dials and gauges...

, with dimensions of 20 by 8 inches (50 by 20 centimeters). A cockpit speech-recognition system (Direct Voice Input
Direct Voice Input
Direct Voice Input is a style of Human-Machine Interaction "HMI" in which the user makes voice commands to issue instructions to the machine...

) provided by Adacel
Adacel
Adacel is a global software technology and systems integrator. The company is a leading developer of critical aviation, speech recognition, defense simulation and security systems for government and commercial enterprises, including the F-35 Lightning II...

 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.

A helmet-mounted display system
Helmet mounted display
A helmet mounted display is a device used in some modern aircraft, especially combat aircraft. HMDs project information similar to that of head-up displays on an aircrew’s visor or reticle, thereby allowing him to obtain situational awareness and/or cue weapons systems to the direction his head...

 (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 without a HUD. The F-35 is equipped with a right-hand side stick
Side-stick
A side-stick or sidestick controller is an aircraft control column that is located on the side console of the pilot, usually on the righthand side, or outboard on a two-seat flightdeck...

 controller in a standard Lockheed Martin HOTAS
HOTAS
HOTAS, an abbreviation for Hands On Throttle-And-Stick, is the name given to the concept of placing buttons and switches on the throttle stick and flight control stick in an aircraft's cockpit, allowing the pilot to access vital cockpit functions and fly the aircraft without having to remove his...

 configuration.

The Martin-Baker
Martin-Baker
Martin-Baker Aircraft Co. Ltd. is a manufacturer of ejection seats and safety related equipment for aviation. The company origins were as an aircraft manufacturer before becoming a pioneer in the field of ejection seats...

 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. The General Dynamics F-16 Fighting Falcon has a similar cockpit layout and is being used to train pilots until training F-35s become available.

Sensors and avionics

The F-35's sensor and communications suite is intended to facilitate situational awareness, command-and-control and network-centric warfare
Network-centric warfare
Network-centric warfare, also called network-centric operations, is a military doctrine or theory of war pioneered by the United States Department of Defense in the 1990's....

 capability. The main sensor on board the F-35 is its AN/APG-81
APG-81
The AN/APG-81 is an Active Electronically Scanned Array designed by Northrop Grumman Electronic Systems for the F-35 Lightning II.The Joint Strike Fighter AN/APG-81 AESA radar is a result of the US government's competition for the world's largest AESA acquisition contract...

 AESA-radar, designed by Northrop Grumman Electronic Systems
Northrop Grumman Electronic Systems
' was created by Northrop Grumman's acquisition of Westinghouse Electronic Systems Group in 1996. The Electronic Systems sector is a leading designer, developer, and manufacturer of a wide variety of advanced defense electronics and systems. The division has 120 locations worldwide, including 72...

. 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
Lockheed Martin Sniper XR
The Lockheed Martin Sniper Advanced Targeting Pod , designated AN/AAQ-33 in U.S. Military Service, provides positive target identification, autonomous tracking, coordinate generation, and precise weapons guidance from extended standoff ranges. The Sniper ATP is used on the F-15E Strike Eagle, F-16...

 while avoiding making the aircraft more easily detectable.

Six additional passive infrared sensors are distributed over the aircraft as part of Northrop Grumman's AN/AAQ-37 distributed aperture system (DAS),"F-35 Distributed Aperture System (EO DAS)." Northrop Grumman. Retrieved 6 April 2010. which acts as a missile warning system
Missile Approach Warning
A Missile Approach Warning system is part of the avionics package on some military aircraft. A sensor detects attacking missiles. Its automatic warning cues the pilot to make a defensive maneuver and deploy the available countermeasures to disrupt missile tracking.Guided Surface to Air Missile ...

, 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
BAE Systems
BAE Systems plc is a British multinational defence, security and aerospace company headquartered in London, United Kingdom, that has global interests, particularly in North America through its subsidiary BAE Systems Inc. BAE is among the world's largest military contractors; in 2009 it was the...

 and include Northrop Grumman components. The communications, navigation and identification (CNI) suite is designed by Northrop Grumman and includes the Multifunction Advanced Data Link
Multifunction Advanced Data Link
Multifunction Advanced Data Link is a future data waveform to provide secure data-linking technology between stealth aircraft. It began as a method to coordinate between F-35 aircraft , but HQ Air Combat Command wants to expand the capabiltiy to coordinate future USAF strike forces of all AF...

 (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 low observability.

The F-35 has been designed with synergy between sensors as a specific requirement, with the "senses" of the aircraft expected to provide a more cohesive picture of the reality around it, and be available in principle for use in any possible way, and any possible combination with one another. 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 previous aircraft, such as the F-22, all software for the F-35 is written in C++
C++
C++ is a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language. It is regarded as an intermediate-level language, as it comprises a combination of both high-level and low-level language features. It was developed by Bjarne Stroustrup starting in 1979 at Bell...

 for faster code development. The Integrity DO-178B real-time operating system (RTOS) from Green Hills Software
Green Hills Software
Green Hills Software is a privately owned company that builds operating systems and development tools for embedded systems. The company was founded in 1982 by Dan O'Dowd and Carl Rosenberg...

 runs on COTS
Commercial off-the-shelf
In the United States, Commercially available Off-The-Shelf is a Federal Acquisition Regulation term defining a nondevelopmental item of supply that is both commercial and sold in substantial quantities in the commercial marketplace, and that can be procured or utilized under government contract...

 Freescale PowerPC processors. The final Block 3 software for the F-35 is planned to have 8.6 million lines of software code. The scale of the program has led to a software crisis
Software crisis
Software crisis is the term used in early days of computing science. The term was used to describe the impact of rapid increases in computer power and the complexity of the problems that could be tackled. In essence, it refers to the difficulty of writing correct, understandable, and verifiable...

 as officials continue to discover that additional software needs to be written. General Norton Schwartz has said that the software is the biggest factor that might delay the USAF's initial operational capability which is now scheduled for April 2016. Michael Gilmore, Director of Operational Test & Evaluation, has written that, "the F-35 mission systems software development and test is tending towards familiar historical patterns of extended development, discovery in flight test, and deferrals to later increments."

The F-35's electronic warfare systems are intended to detect hostile aircraft first, which can then be scanned with the electro-optical system and action taken to engage or evade the opponent before the F-35 is detected. The CATbird avionics testbed for the F-35 program has proved capable of detecting and jamming F-22 radars.

Helmet-mounted display system

The F-35 need not be physically pointing at its target for weapons to be successful. This is possible because of sensors that can track and target a nearby aircraft from any orientation, provide the information to the pilot through his helmet (and therefore visible no matter which way they are looking), and provide the seeker-head of a missile with sufficient information. Recent missile types provide a much greater ability to pursue a target regardless of the launch orientation, called "High Off-Boresight" capability, although the speed and direction in which the munition is launched affect the effective range of the weapon. Sensors use combined radio frequency and infra red (SAIRST) to continually track nearby aircraft while the pilot's helmet-mounted display system
Head-mounted display
A head-mounted display or helmet mounted display, both abbreviated HMD, is a display device, worn on the head or as part of a helmet, that has a small display optic in front of one or each eye .- Overview :...

 (HMDS) displays and selects targets. The helmet system replaces the display suite-mounted head-up display used in earlier fighters.

The F-35's systems provide the edge in the "observe, orient, decide, and act" OODA loop
OODA Loop
The OODA loop is a concept originally applied to the combat operations process, often at the strategic level in military operations. It is now also often applied to understand commercial operations and learning processes...

; stealth and advanced sensors aid in observation (while being difficult to observe), 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.

The problems with the current Vision Systems International helmet mounted display lead Lockheed Martin to issue a draft specification for proposals for an alternative on 1 March 2011. The alternative system will be based on Anvis-9 night vision goggles. It will be supplied by BAE systems. The BAE system does not include all the features of the VSI helmet and is currently intended only for use during the testing program.

In 2011, Lockheed granted VSI a contract to fix the vibration, jitter, night-vision and sensor display problems in their helmet mounted display. The improved displays are expected to be delivered in third quarter of 2013.

Next Generation Jammer

The United States Marine Corps
United States Marine Corps
The United States Marine Corps is a branch of the United States Armed Forces responsible for providing power projection from the sea, using the mobility of the United States Navy to deliver combined-arms task forces rapidly. It is one of seven uniformed services of the United States...

 is considering replacing their Northrop Grumman 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. 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 tailored data streams into remote systems. The ITT
ITT Corporation
ITT Corporation is a global diversified manufacturing company based in the United States. ITT participates in global markets including water and fluids management, defense and security, and motion and flow control...

-Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

 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 experience with broadband electronically steerable antenna arrays. At the same time contracts were also awarded to Raytheon, Northrop Grumman and BAE Systems.

Maintenance

The program's maintenance concept is for any F-35 to be maintained in any F-35 maintenance facility and that all F-35 parts in all bases will be globally tracked and shared as needed.

The aircraft has been designed for ease of maintenance, with 95% of all field replaceable parts "one deep" so that nothing else has to be removed to get to the part in question, the ejection seat can be replaced without removing the canopy, an all-composite skin without the fragile coatings found on other stealth aircraft and low-maintenance electro-hydrostatic actuators instead of hydraulic systems.

Testing

The first F-35A (designated AA-1) was rolled out in Fort Worth
Fort Worth, Texas
Fort Worth is the 16th-largest city in the United States of America and the fifth-largest city in the state of Texas. Located in North Central Texas, just southeast of the Texas Panhandle, the city is a cultural gateway into the American West and covers nearly in Tarrant, Parker, Denton, and...

, Texas on 19 February 2006. The aircraft underwent extensive ground testing at Naval Air Station Joint Reserve Base Fort Worth
Naval Air Station Joint Reserve Base Fort Worth
Naval Air Station Fort Worth Joint Reserve Base or NAS Fort Worth JRB includes Carswell Field, a military airfield located west of the central business district of Fort Worth, in Tarrant County, Texas, United States. This military airfield is operated by United States Navy...

 in late 2006. In September 2006 the first engine run of the F135
Pratt & Whitney F135
The Pratt & Whitney F135 is an afterburning turbofan developed for the F-35 Lightning II single-engine strike fighter. The F135 family has several distinct variants, including a conventional, forward thrust variant and a multi-cycle STOVL variant that includes a forward lift fan...

 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
Boeing 737
The Boeing 737 is a short- to medium-range, twin-engine narrow-body jet airliner. Originally developed as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has developed into a family of nine passenger models with a capacity of 85 to 215 passengers...

, the Lockheed CATBird is used as an avionics 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
Aerial refueling
Aerial refueling, also called air refueling, in-flight refueling , air-to-air refueling or tanking, is the process of transferring fuel from one aircraft to another during flight....

 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 ft (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 takeoff, 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 (411.6 km/h) to 180 knots (352.8 km/h). 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
Lockheed Martin X-35
The Lockheed Martin X-35 was an experimental aircraft developed by Lockheed Martin for the Joint Strike Fighter Program. It was declared the winner over the Boeing X-32 and went on to enter production in the early 21st century as the F-35 Lightning II....

, which achieved the same feat on 20 July 2001. In January 2011, Lockheed Martin reported it had solved a problem with the aluminum bulkhead used only on the F-35B which had cracked during ground testing.
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
Ashton Carter
Ashton Baldwin Carter is a United States national security professional. He is is the United States Deputy Secretary of Defense. Prior to that, He served as Under Secretary of Defense for Acquisition, Technology, and Logistics for President Barack Obama. He is currently on leave from his post as...

 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. As of March 2010, the F-35 program had used a million more man-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 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, it may be possible to reduce this shortfall.

The F-35C carrier variant's maiden flight took place on 7 June 2010, also at NAS Fort Worth JRB
Naval Air Station Joint Reserve Base Fort Worth
Naval Air Station Fort Worth Joint Reserve Base or NAS Fort Worth JRB includes Carswell Field, a military airfield located west of the central business district of Fort Worth, in Tarrant County, Texas, United States. This military airfield is operated by United States Navy...

. 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.

On 9 March 2011 all F-35s were grounded after a dual generator failure and oil leak in flight. This was the first significant flight failure since 2007. Seven of the ten test aircraft were cleared to fly four days later. These aircraft have an older model of generators, unlike the kind that failed in flight. The problem was found to be the result of faulty maintenance rather than a design or construction issue.

As of 3 August 2011, the F-35 fleet has been grounded. This precautionary grounding is in effect while the Joint Program Office investigates the cause of an electrical system failure on test aircraft, F-35A AF-4 during ground tests. The Honeywell-built integrated power package (IPP) failed during a standard engine test following a maintenance check on 2 August at Edwards Air Force Base
Edwards Air Force Base
Edwards Air Force Base is a United States Air Force base located on the border of Kern County, Los Angeles County, and San Bernardino County, California, in the Antelope Valley. It is southwest of the central business district of North Edwards, California and due east of Rosamond.It is named in...

. The IPP is relatively unheralded, but plays a major role in the F-35's performance. It combines the functions of an environment control unit, engine starter and back-up power generator into a single system. The IPP has been a target for concern during the development phase, even though it has never failed before in more than 1,500 flight hours. The JPO was assessing the impact of the grounding on the schedule for the system development and demonstration phase, but the latest version of the schedule included margin for unexpected problems.

As of 10 August 2011, the investigation was ongoing; government and contractor engineering teams, after reviewing initial data, determined that the fleet could safely resume Development Test ground operations. Preliminary root cause inquiries indicate that a control valve did not function properly, which in turn led to the IPP failure. Monitoring of this valve is the mitigating action required to allow ground operations. The F-35 team is revising ground monitoring procedures to ensure testing involving the IPP takes place safely. While initiating DT ground operations is a "major step" for the F-35 fleet returning to flight, further reviews are required prior to lifting the suspension of flight operations for the 20 F-35s currently in flying status. On 18 August 2011, the flight ban was lifted for 18 of the 20 fighters. Two aircraft based at Eglin Air Force Base
Eglin Air Force Base
Eglin Air Force Base is a United States Air Force base located approximately 3 miles southwest of Valparaiso, Florida in Okaloosa County....

 in Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 will remain grounded because they lack the monitoring systems used in developmental test aircraft that can detect any problems in flight.

Training

In 2011, the Director of Operational Test and Evaluation warned that the USAF's plans to start unmonitored flight training that fall "risks the occurrence of a serious mishap".

Procurement and 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 aircraft is expected to cost an additional US$200 billion. The nine major partner nations plan to acquire over 3,100 F-35s through 2035.

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
Memorandum of understanding
A memorandum of understanding is a document describing a bilateral or multilateral agreement between parties. It expresses a convergence of will between the parties, indicating an intended common line of action. It is often used in cases where parties either do not imply a legal commitment or in...

 that brought the UK into the project. Level 2 partners are Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

, which is contributing US$1 billion; and the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

, US$800 million. Level 3 partners are Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

, US$195 million; Canada, US$160 million; Australia, US$144 million; Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

, US$122 million and Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

, US$110 million. Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

 and Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

 have joined as Security Cooperative Participants (SCP).

Variants

The F-35 is being built in three different main versions to suit various combat missions. A fourth variant, the F-35I is an export version for Israel.

F-35A

The F-35A is the conventional takeoff and landing (CTOL
CTOL
CTOL is an acronym for conventional take-off and landing, and is the process whereby conventional aircraft take off and land, involving the use of runways. The aircraft will taxi along the runway until its rotation speed is reached, then climb into the air...

) 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
25 mm caliber
The 25x137 mm caliber/.98425 inch is one of the standard sizes of cannon and autocannon ammunition for NATO forces. The round itself has a length of approximately 223 mm .-Usage:...

 cannon is a development of the GAU-12
GAU-12 Equalizer
The General Dynamics GAU-12/U Equalizer is a five-barrel 25 mm Gatling gun-style rotary cannon. The GAU-12/U is used by the United States, Italy and Spain, which mount the weapon in their fighter jets such as the AV-8B Harrier II, airborne gunships such as the Lockheed AC-130, and land-based...

 carried by the USMC's AV-8B Harrier II
AV-8B Harrier II
The McDonnell Douglas AV-8B Harrier II is a second-generation vertical/short takeoff and landing ground-attack aircraft. An Anglo-American development of the British Hawker Siddeley Harrier, the Harrier II is the final member of the Harrier family that started with the Hawker Siddeley P.1127 in...

. It is designed for increased effectiveness against ground targets compared to the 20 mm
20 mm caliber
The 20 mm caliber is a specific size of cannon or autocannon ammunition, commonly the smallest caliber which is unambiguously a cannon and not a heavy machine gun....

 M61 Vulcan
M61 Vulcan
The M61 Vulcan is a hydraulically or pneumatically driven, six-barreled, air-cooled, electrically fired Gatling-style rotary cannon which fires 20 mm rounds at an extremely high rate. The M61 and its derivatives have been the principal cannon armament of United States military fixed-wing aircraft...

 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 is expected to match an F-16 that is carrying the usual external fuel tank in acceleration performance. It also has an internal laser designator and infrared sensors, equivalent to the Sniper XR
Lockheed Martin Sniper XR
The Lockheed Martin Sniper Advanced Targeting Pod , designated AN/AAQ-33 in U.S. Military Service, provides positive target identification, autonomous tracking, coordinate generation, and precise weapons guidance from extended standoff ranges. The Sniper ATP is used on the F-15E Strike Eagle, F-16...

 pod carried by the F-16, but built in to reduce radar cross section.

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

F-35I

F-35A with Israeli modifications. A senior Israel air force official stated "the aircraft will be designated F-35I, as there will be unique Israeli features installed in them". The United States will not allow for the integration of Israel's own electronic warfare systems into the aircraft’s built-in electronic suite. However, a plug-and-play feature added to the main computer will allow for use of Israeli electronics in an add-on fashion. Israel will be able to fit its own external jamming pod and plans to install its own air-to-air missiles and guided bombs in the F-35’s internal weapon bays. In July 2011, it was reported that the U.S. had agreed to allow Israel to install their own electronic warfare systems and missiles in their F-35s in the future.

Israel Aerospace Industries has considered playing a role in the development of a proposed two-seat F-35. An IAI executive stated, "There is a known demand for two seats not only from Israel but from other air forces. Advanced aircraft are usually two seats rather than single seats."

CF-35

The Canadian CF-35 will differ from the American F-35A through the addition of a drag chute and an F-35B/C style refueling probe. Norway may also use the drag chute option, as they also have icy runways.

F-35B

The F-35B is the short takeoff and vertical landing (STOVL
STOVL
STOVL is an acronym for short take off and vertical landing.This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically...

) variant of the aircraft. Similar in size to the A variant, the B sacrifices about a third of the other version's fuel volume to make room for the vertical flight system
Rolls-Royce LiftSystem
The Rolls-Royce LiftSystem is an innovative propulsion system designed for use in the STOVL variant of the F-35 Lightning II developed during the Joint Strike Fighter Program...

. 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 the F-35A is stressed to 9 g, the F-35B is stressed to 7 g. 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.

Unlike the other variants, because it can land vertically the F-35B has no landing hook. The "STOVL/HOOK" button in the cockpit initiates conversion instead of dropping the hook. 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. The variant's three-bearing swivel nozzle that directs the full thrust of the afterburning jet engine is moved by a “fueldraulic” actuator, using pressurized jet fuel.

The United States Marine Corps plans 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
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...

, and attack roles.

The Royal Air Force and Royal Navy had plans to use the F-35B to replace their Harrier GR9s. One of the Royal Navy requirements for the F-35B design was a Shipborne Rolling and Vertical Landing (SRVL) mode to increase the maximum landing weights for carried weapons via wing lift. This method of landing is slower than arrested landing and could disrupt regular carrier operations. However, in October 2010, the UK announced plans to order to the CATOBAR
CATOBAR
CATOBAR is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier...

 F-35C variant instead.

Italian Navy
Italian Navy
Italian Navy may refer to:* Pre-unitarian navies of the Italian states* Regia Marina, the Royal Navy of the Kingdom of Italy * Italian Navy , the navy of the Italian Republic...

 is preparing Grottaglie air station for future operations with the F-35B. The Italian Navy is to receive 22 aircraft between 2014 and 2021, with its Cavour aircraft carrier set to be modified to operate them by 2016.

Commandant of the Marine Corps, General James Amos has said that, in spite of its increasing costs and schedule delays, there is no plan B to substitute for the F-35B. The F-35B is larger than the aircraft it replaces, which required the USS America (LHA-6)
USS America (LHA-6)
USS America will be the first of the America-class amphibious assault ships for the U.S. Navy, and she will be the fourth American warship to bear this name. The America-class will replace the last of the Tarawa-class amphibious assault ships...

 to be designed without needed well deck capabilities. In 2011, the USMC and USN signed an agreement that the USMC will purchase 340 F-35B and 80 F-35C while the USN will purchase 260 F-35C. The five squadrons of Marine Corps F-35Cs will be assigned to the Navy carriers while the Marine Corps F-35Bs will be used on Amphibious ships and ashore.

On 6 January 2011, Gates said that the 2012 budget would call for a two year pause in F-35B production during which the aircraft may be redesigned, or canceled if unsuccessful. Gates stated, "If we cannot fix this variant during this time frame, and get it back on track in terms of performance, cost and schedule, then I believe it should be canceled."

Lockheed Martin executive vice president Tom Burbage and former Pentagon director of operational testing Tom Christie have said that most of the delays in the total program have been due to issues with the F-35B, which forced massive redesigns on the other versions.

The USMC intends to declare Initial Operational Capability with about 50 F-35s running interim Block 2B software in the 2014 to 2015 timeframe.

Lockheed Martin vice president Steve O’Bryan has said that most F-35B landings will be purely conventional in order to reduce stress on the vertical lift components. Conventional operations also reduce the risk of self-induced foreign object damage.

On 3 October 2011, the F-35B began its initial sea-trials by performing a vertical landing on the deck of the amphibious assault ship USS Wasp
USS Wasp (LHD-1)
USS Wasp is a U.S. Navy multipurpose amphibious assault ship, the tenth to bear the name, the flagship of the Second Fleet and the lead ship of her class. She was built by the Ingalls Shipbuilding division of Litton in Pascagoula, Mississippi. The Navy-Marine Corps team's newest amphibious warship...

.

F-35C

The F-35C carrier variant features larger wings with foldable wingtip sections, larger wing and tail control surfaces for improved low-speed control, stronger landing gear for the stresses of carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

 arrested landings, a twin-wheel nose gear, and a stronger tailhook
Tailhook
A tailhook, also arresting hook or arrester hook, is a device attached to the empennage of some military fixed wing aircraft...

 for use with carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...

 arrestor cables. The larger wing area allows for decreased landing speed while increasing both range and payload. With twice the range on internal fuel as the F/A-18C Hornet, the F-35C achieves much the same goal as the F/A-18E/F Super Hornet.

The United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 will use the F-35C 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 low-observable 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 F-35C was rolled out on 29 July 2009. On 6 November 2010, the first F-35C arrived at Naval Air Station Patuxent River
Naval Air Station Patuxent River
"Pax River" redirects here. For the river, see Patuxent River.Naval Air Station Patuxent River , also known as NAS Pax River, is a United States Naval Air Station located in St. Mary's County, Maryland on the Chesapeake Bay near the mouth of the Patuxent River. It is home to the U.S...

, however, it was determined that the replacement engines for at-sea repair are too large to be transported by current underway replenishment systems. The United States Marine Corps will also purchase 80 F-35Cs, enough for five Marine fighter-attack squadrons, for use with Navy carrier air wing
Carrier air wing
A Carrier Air Wing is an operational naval aviation organization composed of several aircraft squadrons and detachments of various types of fixed wing and rotary wing aircraft...

s in a joint service agreement signed on 14 March 2011.

In October 2010, the United Kingdom decided to order the F-35C, which will be used by both the Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 and the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

. The total number of F-35C aircraft to be procured has not been announced. However, it will be less than the 150 originally planned. The Royal Navy's new Queen Elizabeth class aircraft carriers are large enough to support non-STOVL operations and as a result, at least one carrier will have catapults and arrestor cables installed to allow F-35C and Allied naval aircraft operations. The carrier will typically carry 12 F-35Cs with the ability to deploy up to 36. The UK Strategic Defence & Security Review found that the F-35C's greater endurance in the air meant that fewer aircraft would be needed and that the F-35C has a 25 percent lower lifetime cost than the F-35B.

In 2011 the F-35Cs were grounded for six days because of a software error in the code that was intended to keep the wings from folding in mid-flight. But on 27 July 2011, the F-35C test aircraft CF-3 completed its first steam catapult launch during a test flight in Naval Air Engineering Station Lakehurst
Naval Air Engineering Station Lakehurst
JB MDL Lakehurst is a United States Navy base located approximately south-southeast of Trenton, New Jersey. Lakehurst is under the jurisdiction of the Naval Air Systems Command...

. The TC-13 Mod 2 test steam catapult, representative of current fleet technology, was used. In addition to the catapult launches at varying power levels, the integrated test team is to execute a test plan over three weeks to include dual-aircraft jet blast deflector
Jet blast deflector
A jet blast deflector or blast fence is a safety device that redirects the high energy exhaust from a jet engine to prevent damage and injury. The structure must be strong enough to withstand heat and high speed air streams as well as dust and debris carried by the turbulent air...

 testing and catapult launches using a degraded catapult configuration to measure the effects of steam ingestion on the aircraft.

On 13 August 2011, the F-35 integrated test force completed jet blast deflector (JBD) testing at the Lakehurst facility, with a round of two-aircraft testing. F-35C test aircraft CF-1 along with an F/A-18E tested a combined JBD cooling panel configuration to assess the integration of F-35s in aircraft carrier launch operations. “We completed all of our JBD test points efficiently,” said Andrew Maack, government chief test engineer. “It was a great collaborative effort by all parties.” The government and industry team completed tests that measured temperatures, pressures, sound levels, velocities, and other environmental data. The combined JBD model is to enable carrier deck crews to operate all air wing aircraft, now including the F-35C, as operational tempo requires. Future carrier suitability testing is scheduled throughout 2011, including ongoing catapult testing and the start of arrestment testing in preparation for initial ship trials in 2013.

Specifications (F-35A)

Differences between variants
F-35A
CTOL
F-35B
STOVL
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)
Internal fuel 18,500 lb (8,390 kg) 13,300 lb (6,030 kg) 19,600 lb (8,890 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 on
internal fuel
590 nmi (1,090 km) 450 nmi (833 km) 640 nmi (1,185 km)
Thrust/weight
full fuel
50% fuel
0.87
1.07
0.90
1.04
0.75
0.91


See also

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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