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The F-35 Lightning II, known as the Joint Strike Fighter (JSF) during development, is a single-seat, single-engine military strike fighter, an aircraft that can perform close air support, tactical bombing, and air-to-air combat. Its development is being funded by the United States, the United Kingdom and other partner governments. It is being designed and built by an aerospace industry team led by Lockheed Martin and lead partners Northrop Grumman and BAE Systems.

The JSF program was created to replace various aircraft while keeping development, production, and operating costs down. This was pursued by building three variants of one aircraft. The variants, which share more than 80% of their parts, include:

International participation

The primary customers and financial backers are the United States and the United Kingdom. Eight other nations are also funding the plane's development and will decide in 2006 whether or not to purchase it. Total program development costs, less procurement, are estimated at over $40 billion, of which the bulk has been underwritten by the US.*

There are three levels of international participation. The United Kingdom is the sole level 1 partner, contributing slightly over States dollar|US$" target="_blank" >*2 billion, about 10% of the development costsLevel 2 partners are Italy, which is contributing US$1 billion, and the Netherlands, US$800 million. At level 3 are Turkey, US$175 million; Australia, US$144 million; Norway, US$122 million; Denmark, US$110 million; and Canada, US$100 million. 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. Israel and Singapore have also joined as Security Cooperative Participants.Katherine V. Schnasi [http://www.gao.gov/new.items/d04554.pdf Joint Strike Fighter Acquisition: Observations on the Supplier Base US Accounts Office. Retrieved Feb. 08, 2006.

Some of the partner countries have wavered in their public commitment to the JSF program, hinting or warning that unless they receive more subcontracts or technology transfer, they will forsake JSF purchases for the Eurofighter Typhoon, Gripen or Rafale.

United Kingdom participation

The British government signed on early to the JSF effort, but its officials have been frustrated by U.S. refusal to hand over sensitive technology that would allow Britain to maintain and upgrade its fighters without U.S. involvement.

For five years, British officials sought an ITAR waiver to secure greater technology transfer. This request, which has the blessing of the Bush administration, has been repeatedly blocked by U.S. Representative Henry Hyde, who says the technology may find its way to other countries.Spiegel, Peter, MSNBC UK denied waiver on US arms technology. Financial Times (MSNBC reprint). Retrieved Feb. 08, 2006. BAE Systems CEO Mike Turner complained that the U.S. had denied access to the plane's source code. On 21 December 2005, an article in the Glasgow Herald quoted the chairman of the Commons Defence Select Committee as saying "the UK might have to consider whether to continue in the program" if no access were granted.UK Defence Committee Statement MoD 'slippage' set to leave forces with reduced capability, says committee UK Parliament. Retrieved Feb. 08, 2006. Lord Drayson, Minister for Defence Procurement, took a firmer stance during a March 2006 visit to Washington: "We do expect the software technology transfer to take place. But if it does not take place we will not be able to purchase these aircraft," and he said there was a Plan B if the deal fell through. Matt Chapman Britain warns US over jet software codes vunet.com Retrieved March. 16 2006. This may have been the development of a navalized Typhoon.Evidence to UK Defence Select Committee. Retrieved Apr. 1, 2006.

On May 27 2006, President George W. Bush and Prime Minister Tony Blair announced that "Both governments agree that the UK will have the ability to successfully operate, upgrade, employ, and maintain the Joint Strike Fighter such that the UK retains operational sovereignty over the aircraft."Financial Times Bush gives way over stealth fighter. Retrieved May 27, 2006

Australian participation

In May 2005, the Australian government announced that it would delay its planned 2006 decision on buying the JSF to 2008, and thus past the term of the present government.

Royal Australian Air Force opinion remains strongly in favor of the JSF, but media, lobby groups and politicians have raised doubts that the aircraft will be ready in time to replace the aging Australian air force fleet of General Dynamics F-111 strike aircraft and F/A-18 Hornet fighters. Some critics say the F-22 Raptor may be a better choice, offering better range, dogfighting capability, and supercruise at a cost that may not be much more than the F-35Related discussions and analyzes on Air Power Australia web site. — claims that as of July 2006 are being examined in a parliamentary inquiry.Inquiry into Australian Defence Force Regional Air Superiority, Joint Standing Committee on Foreign Affairs, Defence, and Trade, Australian Parliament

Program history

The Joint Advanced Strike Technology (JAST) program was created in 1993, implementing one of the recommendations of a United States Department of Defense (DoD) "Bottom-Up Review." (The review also led the Pentagon to continue the F-22 and F/A-18E/F programs, cancel the Multi-Role Fighter (MRF) and the A/F-X programs, and curtail F-16 and F/A-18C/D procurement.)

The JAST program office was established on January 27 1994, to develop aircraft, weapons, and sensor technology with the aim of replacing several U.S. and UK aircraft with a single family of aircraft.

Two contracts to develop prototypes were awarded on November 16 1996; one each to Lockheed Martin and Boeing. Each firm would produce two aircraft to demonstrate conventional takeoff and landing (CTOL), carrier takeoff and landing (CV version), and short takeoff and vertical landing (STOVL).

Also in 1996, the UK Ministry of Defence launched the Future Carrier Borne Aircraft project. This program sought a replacement for the Sea Harrier (and later the Harrier GR7); the Joint Strike Fighter was selected in January 2001.

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. DoD officials and the UK Minister of Defence Procurement said the X-35 consistently outperformed the X-32, although both met or exceeded requirements. It should be noted that Lockheed's X-35 substantially broke the budget limitations of the competition, yet still won the contract.

On February 19 2006, the first F-35 (USAF version) was rolled out in Fort Worth, Texas. The aircraft will undergo extensive ground testing and then flight tests towards the end of 2006.

Naming

Lockheed Martin's decision to call its prototype the X-35 followed the proper sequence for the Air Force's X-plane family. But when the U.S. Department of Defense designated the production plane F-35, it violated tradition, which called for the plane to be the "F-24", following the YF-23 Black Widow II.

On July 7 2006, the U.S. Air Force officially announced the name of the F-35: Lightning II,"Lockheed Martin Joint Strike Fighter Officially Named 'Lightning II.'" Official Joint Strike Fighter program office press release. July 7 2006. in honor of Lockheed's World War II-era twin-prop P-38 Lightning and the Cold War-era jet English Electric Lightning. English Electric's aircraft division was incorporated into BAC, a predecessor of F-35 partner BAE Systems. Other names previously listed as contenders were Kestrel, Phoenix, Piasa, Black Mamba, and Spitfire II. Lightning II was also an early name for the aircraft that became the F-22 Raptor. Lightning II can be used in both the U.S. and UK, which have previous aircraft named "Lightning."

Design

The F-35A is the smallest, lightest version, intended for use primarily by the U.S. Air Force. The F-35C, intended for naval use, has the largest wingspan, allowing high glide angles and more control at low landing speeds, and the heaviest, most reinforced fuselage to endure arrested landings and catapult launches. The F-35B STOVL aircraft uses the complex Remote Shaft-Driven Lift Fan concept. Turbine power is diverted forward via a clutch-and-bevel gearbox, to a vertically mounted, contra-rotating lift fan located forward of the main engine in the center of the aircraft. Bypass air from the turbofan exhausts through a pair of roll-post nozzles on either side of the fuselage, while the lift fan and the LP turbine streams exhaust through thrust-vectoring nozzles. In effect, the F-35B power plant acts as a flow multiplier. It also reduces environmental effects during landing: for example, limiting heat transfer on an aircraft carrier deck.

During concept definition, two Lockheed airframes were flight-tested: the Lockheed X-35A (which was later converted into the X-35B), and the larger-winged X-35C.Joint Strike Fighter official site - History page Both the Boeing X-32 and X-35 power plants were derived from Pratt & Whitney's F119, with the STOVL variant of the latter incorporating a Rolls Royce Lift Fan module.

The X-32 STOVL variant redirected engine exhaust gases through to thrust-vectoring nozzles to provide lift during a STOVL landing, but the lift was deemed insufficient compared to the Lockheed design. In addition, some of Boeing's hover-tests were marred with engine surge/fade problems determined to be caused by the engine's hot exhaust being ingested in the large forward inlet. While some fixes were intended for developmental aircraft, the short distance from the inlet to the hot exhaust virtually ensured that this problem could not be permanently resolved in the Boeing design. Finally, the large front air intake was widely regarded as both ugly and inefficient. Critics said Boeing designed an aircraft "only its mother would love", violating the maxim "if it looks good, it flies good" (which probably refers to the aesthetic qualities of highly streamlined designs).

Arguably the most persuasive demonstration of the X-35's capability was the final qualifying Joint Strike Fighter flight trials, in which the X-35B STOVL aircraft took off in less than 500 feet, went supersonic, and landed vertically *.

Elements of the F-35 design were pioneered by the F-22 Raptor. The airframe appears smaller but quite similar to the F-22, which has two engines to the F-35's one. Some technology was also licensed by Lockheed from Russian manufacturer Yakovlev, in particular an exhaust duct design pioneered on the Yak-141 prototype. *

Stealth technology makes the aircraft hard to detect as it approaches short-range tracking X-band radar, although its rear is much more easily spotted by X-band, and the aircraft is not stealthy to long-range L-band radar.

Some specific improvements over current aircraft are:

  • Durable, low-maintenance stealth technology
  • Integrated avionics and sensor fusion that combine information from off- and onboard sensors to increase the pilot's situational awareness and improve identification and weapon delivery, and to relay information quickly to other C2 nodes.
  • Low life-cycle costs

The F-35, which will have helmet-mounted displays, will be the first combat aircraft in modern times without a heads-up-display.

Directed-energy weapons

Directed-energy weapons may be installed in conventional takeoff F-35 Lightning IIs, whose lack of a direct lift fan frees up about 100 ft³ (2.8 m³) of space Morris, Jefferson (26 September 2002). Keeping Cool A Big Challenge For JSF Laser, Lockheed Martin Says. Aerospace Daily Retrieved 8 February 2006. and whose engine provides more than 27,000 hp (20 MW) for electrical power.Fulghum, David A. (July 8 2002). Lasers Being Developed for F-35 and AC-130. Aviation Week and Space Technology Retrieved 8 February 2006. Some concepts, including solid state lasers and high-power microwave beams, may be nearing operational status. Fulghum, David A. (July 22 2002). Lasers, HPM Weapons Near Operational Status. Aviation Week and Space Technology Retrieved 8 February 2006.

Analysis of JSF program

JSF critics say it suffers from ill-defined design goals; that it has insufficient range to replace dedicated bombers; that its inability to supercruise limits it as an air defense platform, and that it is almost certain to suffer cost overruns and lengthy development delays. Indeed, through 2004, the JSF's total projected cost had risen 23% to US$244 billion, and as of April 2006 the Pentagon is projecting the budget to rise to US$276.4 billion. They say militaries may need to buy other kinds of aircraft to fill the gap between the retirement of older planes and the arrival of the JSF.

Close air support theorists, especially those with experience flying the A-10 on those missions, are vocally skeptical about the F-35's capacity to carry out that role. They point to the claim during procurement of the F-16 that it would replace the A-10, which it did not, and to the F-35's similar shortcomings for the close air support mission, specifically its small gun and ammunition capacity, and the tight constraints on the number and variety of bombs and missiles it can carry without sacrificing its stealth characteristics.

Its defenders say the F-35 was never intended to replace bombers or be an air defense platform, and they say a thorough requirements definition process with years of analysis and international participation has mitigated cost and schedule concerns. The potential solid state laser is also offered as a mitigating factor for its limited armament for the close air support role, since aerial refueling would essentially also rearm the laser, which could be used even after enemy ground forces had closed too much with friendly ground forces for employment of explosive armaments.

Proponents say the multi-role design philosophy has been proven in combat by the F-16 Fighting Falcon and the F-18 Hornet, and point to several nations, mainly F-16 and F-18 users, that have committed substantial sums to become minority partners in the JSF manufacturing team. They say that even without substantial performance advances over existing planes, the F-35's stealthiness and information warfare technology make it an enticing product.

The program's advocates see the JSF's joint-development concept as an opportunity to break out of the decades-old pattern of U.S. military aircraft procurement, allowing commonality and saving development and operating costs. This follows the philosophy behind the SEPECAT Jaguar and Panavia Tornado international development programs. Accordingly, JSF is the first U.S. aircraft program to consider cost as an independent variable. Unlike earlier programs in which extra features always boosted the cost, such changes are not permitted in JSF development.

JSFs will feed diagnostic information into the ground-based Autonomic Logistic Information System, built by Lockheed Martin Simulation Training and Support, to make the aircraft less expensive to operate and maintain.

Cost-to-weight ratio

The major technical problem was the F-35B variant's mass, which was reported to be one metric ton (2,200 pounds) or 8%, over the target, threatening performance requirements.

Lockheed Martin solved the weight problem by adding engine thrust and shedding more than a ton by: thinning the aircraft's skin; shrinking the weapons bay and vertical tails; redesigning the wing-mate joint, portions of the electrical system, and the portion of the aircraft immediately behind the cockpit; and rerouting some thrust from the roll-post outlets to the main nozzle. Fulghum, David A.; Wall, Robert (19 September 2004). USAF Plans for Fighters Change. Aviation Week and Space Technology Retrieved Feb. 08, 2006.

The smaller weapons bay will return the F-35B to its original 2 x 1000-lb (450-kg) internal-weapons carriage. This is not expected to hinder close air support missions, which are likely to take place after enemy air defenses are down, but may make the "B" variant different from the other two, boosting costs.

The internal weapons are stored offline to the external air flow, which will complicate weapons certification testing — no demonstrations of weapons delivery capability were done prior to contract award.

USAF STOVL purchase?

As costs grow, there have been rumors about cancelling the F-35B variant. However, U.S. operations in Afghanistan have highlighted a need for jump jets in unimproved battlespaces, leading to a hazy USAF "commitment" to buy F-35B and preserve the economic rationale to produce the STOVL jets needed by the USMC, RN, and RAF.

The USAF has reportedly investigated buying up to 216 STOVL F-35s, enough to outfit three wings. One option batted around and discarded was a fourth, F-35D, variant that would have a different propulsion system to increase emphasis on STOL capability over that of VTOL, a larger wing to allow more fuel, an interior cannon (as opposed to the USMC external gun pod), and changes to in-flight refueling (sacrificing compatibility with Air Force KC-135 Stratotankers, which only use the flying boom in-flight refueling system, but not the KC-10 Extender). Should USAF's new tanker program include substantial hose-and-drogue refueling capability, the feasibility of the Air Force operating the F-35B will increase.

Specifications

Some information is estimated.

Manufacturing responsibilities

Media

Further reading

  • Spick, Mike (2002), The Illustrated Directory of Fighters. Salamander ISBN 1-84065-384-1
  • Kopp, Carlo; Goon, Peter, Australian Aviation, JSF related articles.

Notes and references

External links

See also

British attack aircraft 2000-2009 | British fighter aircraft 2000-2009 | Carrier-based aircraft | Fleet Air Arm | Stealth aircraft | U.S. attack aircraft 2000-2009 | U.S. fighter aircraft 2000-2009 | VTOL aircraft

أف 35 | F-35 | F-35 Lightning II | F-35 | Lockheed Martin F-35 | Lockheed F-35 Joint Strike Fighter | F-35 | Lockheed Martin F-35 | F-35 | F-35 Lightning II | F-35 (戦闘機) | F-35 Lightning II | Lockheed F-35 Joint Strike Fighter | F-35 | F-35 | F-35聯合攻擊戰鬥機

 

This article is licensed under the GNU Free Documentation License. It uses material from the "F-35 Lightning II".

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