F-35 Lightning II

F-35 Lightning II

The F-35 Lightning II takes off for its first flight at Joint Reserve Base Fort Worth, Texas, 15 December 2006.
Type Multirole fighter
Manufacturers Lockheed Martin Aeronautics
Northrop Grumman
BAE Systems
Maiden flight 15 December 2006
Introduction 2011 (scheduled)
Status Under development/pre-production
Primary users United States Air Force
United States Navy
United States Marine Corps
Royal Air Force / Royal Navy
Produced 2003-present
Unit cost F-35A: US$48 million
F-35B: US$62 million
F-35C: US$63 million[1]
Developed from Lockheed Martin X-35
The F-35 Lightning II is a single-seat, single-engine, stealth-capable military strike fighter, a multi-role aircraft that can perform close air support, tactical bombing, and air-to-air combat. The F-35 descended from the X-35 of the Joint Strike Fighter (JSF) program. 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 major partners BAE Systems and Northrop Grumman. Demonstrator aircraft flew in 2000;[2] a production model first took flight on 15 December 2006.[3]

[edit] Development

[edit] JSF Program history
Main article: Joint Strike Fighter competition

Original F-35 Joint Strike Fighter Logo
Boeing X-32 (left) and Lockheed Martin X-35 prior to down-select in 2001, where the X-35 was chosen. DoD photo
F-35 Lightning II/JSF Logo
[edit] Requirement
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, sharing 80% of their parts:

F-35A, conventional takeoff and landing (CTOL) variant.
F-35B, short-takeoff and vertical-landing (STOVL) variant.
F-35C, carrier-based variant.

[edit] Origins and X-32 vs. X-35
The Joint Strike Fighter evolved out of several requirements for a common fighter to replace existing types. The actual JSF development contract was signed on 16 November 1996.

The contract for System Development and Demonstration (SDD) was awarded on 26 October 2001 to Lockheed Martin, whose X-35 beat the Boeing X-32. DoD officials and the UK Minister of Defence Procurement said the X-35 consistently outperformed the X-32, although both met or exceeded requirements. The designation of the fighter as "F-35" came as a surprise to Lockheed, which had been referring to the aircraft in-house by the designation "F-24."[4]


[edit] Naming
On 7 July 2006, the U.S. Air Force officially announced the name of the F-35: Lightning II,[5] in honor of Lockheed's World War II-era twin-prop P-38 Lightning and the Cold War-era jet, the English Electric Lightning. English Electric'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 company name for the aircraft that became the F-22 Raptor.


[edit] Design

The F-35A being towed to its inauguration ceremony on 7 July 2006The F-35 appears to be a smaller, slightly more conventional, one-engine sibling of the sleeker, two-engine F-22 Raptor, and indeed, drew elements from it. The exhaust duct design was inspired by the General Dynamics Model 200, a 1972 VTOL aircraft designed for the Sea Control Ship.[6]

Lockheed teamed with the Yakovlev Design Bureau in the 1990s, which has led to some speculation about ties with the quite different Yakovlev Yak-141 'Freestyle'.[7]

Stealth technology makes the aircraft hard to detect as it approaches short-range tracking radar.

Some improvements over current-generation fighter 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 command and control (C2) nodes;
High speed data networking including IEEE-1394b [8] and Fibre Channel [9]
Low life-cycle costs.[citation needed]
Although helmet-mounted displays have already been integrated into some fourth-generation fighters such as the Swedish JAS 39 Gripen, the F-35 will be the first in which helmet-mounted displays replace a head-up display altogether.[10]


[edit] Sensors

EOTS under the nose of a mockup of the F-35.The main sensor on board the F-35 is its AN/APG-81 AESA-radar, designed by Northrop Grumman Electronic Systems.[11] It is augmented by the Electro-Optical Targeting System (EOTS) mounted under the nose of the aircraft, designed by Lockheed Martin and BAE.[12] Further electro-optical sensors are distributed over the aircraft as part of the AN/AAS-37 system which acts as missile warning system and can aid in navigation and night operations.


[edit] Thrust-to-weight ratio
The F-35B variant was in danger of missing performance requirements because it weighed too much — reportedly, by 2,200 pounds (1,000 kg) or 8%. In response, Lockheed Martin added engine thrust and shed more than a ton by thinning the aircraft's skin; shrinking the weapons bay and vertical tails; rerouting some thrust from the roll-post outlets to the main nozzle; and redesigning the wing-mate joint, portions of the electrical system, and the portion of the aircraft immediately behind the cockpit.[13]

The internal weapons are stored offline to the external air flow, which will complicate weapons certification testing.[citation needed]


[edit] Manufacturing responsibilities
Lockheed Martin Aeronautics is the prime contractor and performs aircraft final assembly, overall system integration, mission system, and provides forward fuselage, wings and flight controls system. Northrop Grumman provides Active Electronically Scanned Array (AESA) radar, center fuselage, weapons bay, and arrestor gear. BAE Systems provides Aft fuselage and empennages, horizontal and vertical tails, crew life support and escape systems, Electronic warfare systems, fuel system, and Flight Control Software (FCS1). Alenia will perform final assembly for Italy, the Netherlands and probably all European aircraft. At the moment it's not decided if this model will be identical to the American one or if part of the avionics will be developed in Italy. [14]


[edit] Operational history

[edit] Testing
On 19 February 2006, the first F-35A (USAF version) was rolled out in Fort Worth, Texas. The aircraft underwent extensive ground testing at Naval Air Station Fort Worth Joint Reserve Base in fall 2006. On 15 September 2006 the first engine run of the F135 afterburning turbofan was conducted in an airframe, with the tests completed on 18 September after a static run with full afterburner. The engine runs were the first time that the F-35 was completely functional on its own power systems.[15] On 15 December 2006, the F-35 completed its maiden flight.


[edit] International participation
The primary customers and financial backers are the United States and the United Kingdom. Eight other nations are also funding the aircraft's development and will decide in 2007 whether to purchase it. Total development costs are estimated at more than US$40 billion (underwritten largely by the United States), while the purchase of an estimated 2,400 planes is expected to cost an additional US$200 billion.[16]

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, about 10% of the development costs[17] under the 1995 Memorandum of Understanding that brought the UK into the project.[18] Level 2 partners are Italy, which is contributing US$1 billion; and the Netherlands, US$800 million. Level 3 partners are Canada, US$440 million; Turkey, US$175 million; Australia, US$144 million; Norway, US$122 million; and Denmark, US$110 million. Israel and Singapore have joined as Security Cooperative Participants.[19]

Some of the partner countries have wavered in their public commitment to the JSF program, hinting or warning that unless they receive more subcontracts or technology transfer, they will forsake JSF for the Eurofighter Typhoon, Saab Gripen, Dassault Rafale or simply upgrade their existing aircraft. Norway has several times threatened to put their support on hold unless substantial guarantees for an increased industrial share is provided. Despite this Norway has signed all the Memoranda of Understanding, including the latest one detailing the future production phase of the JSF program. They have, however, indicated that they will increase and strengthen their cooperation with both competitors of the JSF, the Typhoon and the Gripen. "[20]


[edit] United Kingdom
Main article: Joint Combat Aircraft
The United Kingdom plans to acquire versions of the F-35 for its Royal Air Force and the Royal Navy.

The UK became increasingly frustrated by a lack of US commitment to grant access to the technology that would allow the UK to maintain and upgrade its F-35s without US involvement. This is understood to relate mainly to the software of the vehicle. 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 US Representative Henry Hyde, who says that the UK needs to tighten its laws protecting against the unauthorized transfer of the most advanced US technology to third parties.[21]

BAE Systems CEO Mike Turner complained that the US had denied his company access to the aircraft's source code. On 21 December 2005, an article in the Glasgow Herald quoted the chairman of the House of Commons Defence Select Committee as saying "the UK might have to consider whether to continue in the programme" if no access were granted.[22] 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.[23] This may have been the development of a navalized Typhoon.[24]

On 27 May 2006, President George W. Bush and Prime Minister Tony Blair announced that "Both governments agree that the UK will have the ability to successfully operate, upgrade, employ, and maintain the Joint Strike Fighter such that the UK retains operational sovereignty over the aircraft."[25] Despite this, concerns were still expressed about the lack of technology transfer as late as December 2006. Nevertheless, on 12 December 2006, Lord Drayson signed an agreement which met the UK's demands for further participation, i.e., access to software source codes and operational sovereignty. The agreement allows "an unbroken British chain of command" for operation of the aircraft. Drayson said Britain would "not be required to have a US citizen in our own operational chain of command".[26] Drayson also said, however, that Britain is still considering an unspecified "Plan B" alternative to buying the Joint Strike Fighter.

On 25 July 2007, the Ministry of Defence confirmed that they have placed orders for two new aircraft carriers that will allow the purchase of the F-35B variant.[27]


[edit] Australia

Australian Minister for Defence Dr Brendan Nelson signing the JSF Production, Sustainment and Follow-on Development Memorandum of Understanding in December 2006In 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. Australia, like the UK, has insisted it must have access to all software needed to modify and repair aircraft. Analysis conducted by the Royal Australian Air Force has determined that the F-35 "is the most suitable aircraft for Australia’s needs".[28]

There has been debate in Australia over whether the F-35 is the most suitable aircraft for the RAAF. Some media reports, lobby groups and politicians have raised doubts that the aircraft will be ready in time to replace the RAAF's aging fleet of General Dynamics F-111 strike aircraft and F/A-18 Hornet fighters. Some critics say the more expensive F-22 or the Eurofighter may be better choices, both offering better range, dogfighting capability, and supercruise at a cost that may not be much more than the F-35[29] — claims that as of July 2006 are being examined in a parliamentary inquiry.[30]

In a statement released in early August 2006, Australian Defence Minister Dr. Brendan Nelson revealed that whilst the F-35 still had governmental support, Australia is starting to investigate other possible aircraft should the F-35 prove to be unfeasible.[31] In October 2006 the deputy chief of the Air Force, Air Vice Marshal John Blackburn, publicly stated that the RAAF had ruled out the purchase of interim strike aircraft to cover any delays to the F-35 program and believed that the F-35 was suitable.[32] However, on 6 March 2007, Dr. Nelson announced the Australian Government would purchase 24 F/A-18F Super Hornets from Boeing to fill the gap left by the retiring F-111 strike bombers at a cost of potentially A$6 billion.[33] Nonetheless, Dr. Nelson says he continues to endorse Australia’s purchase of the F-35. Speaking on Australian television in March 2007, Dr. Nelson stated that 5% of the capability of the F-35 is classified, claiming that, "that's the five percent that really counts."[34]

On 13 December 2006, Minister Nelson signed the JSF Production, Sustainment and Follow-on Development Memorandum of Understanding. This agreement provides the cooperative framework for the acquisition and support of the JSF over its life.[35] Australia is expected to purchase 100 F-35As at a cost of approximately $16 billion AUD.[36]


[edit] Turkey
On 12 July 2002, Turkey became the seventh international partner in the JSF Project, joining the United Kingdom, Italy, the Netherlands, Canada, Denmark and Norway. On 25 January 2007, Turkey signed a memorandum of understanding (MoU) for involvement in F-35 production. Turkey is expected to order 100 F-35A "CTOL/Air Force versions" at a reported cost of $11 billion.[37] It is reported that the aircraft will be produced under license in Turkey by Turkish Aerospace Industries (TAI).

A Letter of Intent (LOI) was signed between TAI and Northrop Grumman ISS (NGISS) International on 6 February 2007. With the LOI, TAI becomes the second source for the F-35 Lightning II center fuselage during the JSF Signing. The number of center fuselages to be produced by TAI will be determined depending on the number of F-35s Turkey will procure and the number of F-35s to be produced worldwide. The LOI represents a potential value in excess of $3 billion.[citation needed]


[edit] Other nations

[edit] Israel
In 2003, Israel signed a letter of agreement, worth almost $20 million, to formally join the system development and demonstration (SDD) effort for the F-35 as a "security cooperation participant" (SCP).[38] The Israeli Air Force (IAF) stated in 2006 that the F-35 is a key part of IAF's recapitalization plans, and that Israel intends to buy over 100 F-35A fighters at an estimated cost of over $5 billion to replace their F-16s over time.[39] Israel was reinstated as a partner in the development of the F-35 on 31 July 2006, after Israeli participation was put on hold following the Chinese arms deal crisis.[40]


[edit] India
The F-35 is a potential offer to the Indian Air Force as of July 2007. This has been interpreted as part of a tactic to sell the F-16 as a multi-role fighters to the IAF.[41]


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


[edit] F-35A
The F-35A, the conventional takeoff and landing (CTOL) variant intended for the US Air Force and other air forces. It is the smallest, lightest F-35 version and is the only variant equipped with an internal gun, the GAU-12/U. This 25 mm cannon, a development of the 20 mm M61 Vulcan carried by USAF fighters since the F-104 Starfighter, is also carried by the USMC's AV-8B Harrier II.

The F-35A not only matches the F-16 in maneuverability, instantaneous and sustained high-g performance, but also outperforms it in stealth, payload, range on internal fuel, avionics, operational effectiveness, supportability and survivability.[citation needed] It also has an internal laser designator and infra-red sensors.

It is primarily intended to replace both the U.S. Air Force's F-16 Fighting Falcons and A-10 Thunderbolt IIs, beginning in 2011.


[edit] F-35B

X-35B lift fan; the VTOL propulsion system is designed and manufactured by Rolls-Royce plcThe F-35B is the short takeoff and vertical landing (STOVL) variant aircraft. The F-35B is similar in size to the Air Force F-35A, trading fuel volume for vertical flight systems. Like the AV-8 Harrier II, guns will be carried in a ventral pod. Vertical flight is by far the riskiest, and in the end, a decisive factor in design.

Instead of lift engines, or rotating nozzles on the engine fan and exhaust like the Pegasus-powered Harrier, the F-35B uses a vectoring cruise nozzle in the tail, i.e. the rear exhaust turns to deflect thrust down, and an innovative shaft-driven Lift Fan, patented by Lockheed Martin and developed by Rolls-Royce.[42] Somewhat like a turboprop built within the fuselage, engine shaft 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 cruise engine turbofan exhausts through a pair of roll-post nozzles in the wings on either side of the fuselage, while the lift fan balances the vectoring cruise nozzle at the tail. This system is more similar to the Russian Yak-141 and German VJ 101D/E[43] than previous STOVL designs, such as the Harrier with thrust vectoring.

In effect, the F-35B power plant acts as a flow multiplier, much as a turbofan achieves efficiencies by moving unburned air at a lower velocity, and getting the same effect as the Harrier's huge, but supersonically impractical, main fan. Like lift engines, this added machinery is dead weight during flight, but increased lifting power increases takeoff payload by even more. The cool fan exhaust also reduces the harmful effects of hot, high-velocity air which can harm runway pavement or an aircraft carrier deck. Though potentially risky and complicated, it was made to work to the satisfaction of DOD officials.

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.[44] The F-35 power plant is derived from Pratt & Whitney's F119 or GE Rolls Royce fighter team's F136, with the STOVL variant of the latter incorporating a Rolls-Royce Lift Fan module.

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 (150 m), went supersonic, and landed vertically — a feat that Boeing's entry was unable to achieve.[45]

This variant is intended to replace the later derivatives of the Harrier Jump Jet, which was the world's first operational short takeoff / vertical landing fighter/ground attack aircraft. The RAF and Royal Navy will use this variant to replace the Harrier GR7/GR9s. The U.S. Marine Corps will use the F-35B to replace both its AV-8B Harrier II and F/A-18 Hornet fighters. The B variant is expected to be available beginning in 2012.


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

The U.S. Navy intends to buy 480 F-35Cs to replace the F/A-18A, -B, -C, and -D Hornets, which replaced subsonic but long-ranged attack types such as the A-7 Corsair and A-6 Intruder. It will also serve as a stealthier complement to the Super Hornet[46]. On 27 June 2007, the carrier variant completed its Air System Critical Design Review (CDR). This allows the F-35C to go to Low Rate Initial Production. [47]

The C variant is expected to be available beginning in 2012.


[edit] Specifications (F-35 Lightning II)

The first of 15 pre-production F-35sNote: Some information is estimated.

Data from F-35 Program brief[48]

General characteristics
Crew: 1
Length: 50 ft 6 in (15.37 m)
Wingspan: 35 ft 0 in (10.65 m)
Height: 17 ft 4 in (5.28 m)
Wing area: 459.6 ft² (42.7 m²)
Empty weight: 26,000 lb (12,000 kg)
Loaded weight: 44,400 lb (20,100 kg)
Max takeoff weight: 60,000 lb (27,200 kg)
Powerplant: 1× Pratt & Whitney F135 afterburning turbofan
Dry thrust: 28,000 lbf[49] (128 kN)
Thrust with afterburner: 43,000 lbf (191 kN)
Secondary (High Performance), in development: 1× General Electric/Rolls-Royce F136 afterburning turbofan, >178 kN (40,000 lbf)
Lift fan (STOVL): 1× Rolls-Royce Lift System driven from either F135 or F136 power plant, 18,000 lbf (80 kN)
Performance
Maximum speed: >Mach 1.8 (1,200 mph, 1,931 km/h)
Range: ≈1,200 nmi (1,400 mi, 2,200 km) on internal fuel
Combat radius: 600 nmi (690 mi, 1,110 km)
Rate of climb: classified (not publicly available)
Wing loading: 91.4 lb/ft² (446 kg/m²)
Thrust/weight:

With full fuel: 0.968
With 50% fuel: 1.22[49]

F-35A and F-35C Armament
Weapons bay on a mockup of the F-35.Armament

1 × GAU-12/U 25 mm cannon — slated to be mounted internally with 180 rounds in the F-35A and fitted as an external pod with 220 rounds in the F-35B and F-35C.[citation needed]
Internally (current planned weapons for integration), up to four AIM-120 AMRAAM, AIM-9X Sidewinder or AIM-132 ASRAAM internally or two air-to-air and two air-to-ground weapons (up to two 2,000 lb weapons in A and C models; two 1000 lb weapons in the B model) in the bomb bays. These could be AMRAAM, the Joint Direct Attack Munition (JDAM) — up to 2,000 lb (910 kg), the Joint Standoff Weapon (JSOW), Small Diameter Bombs (SDB) — a maximum of four in each bay, the Brimstone anti-armor missiles, Cluster Munitions (WCMD) and High Speed Anti-Radiation Missiles (HARM). The MBDA Meteor air-to-air missile is currently being adapted to fit internally in the missile spots and may be integrated into the F-35.
At the expense of being more detectable by radar, many more missiles, bombs and fuel tanks can be attached on four wing pylons and two wingtip positions. The two wingtip pylons can only carry short-range air-to-air missiles (AIM-9s), while the Storm Shadow and Joint Air to Surface Stand-off Missile (JASSM) cruise missiles can be carried in addition to the stores already integrated. An air-to-air load of 12 AIM-120s and two AIM-9s is conceivable using internal and external weapons stations, as well as a configuration of six two thousand pound bombs, two AIM-120s and two AIM-9s.

[edit] 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 with access to a drive shaft capable of delivering more than 27,000 hp (20 MW).[50][51] Some concepts, including solid state lasers and high-power microwave beams, may be nearing operational status.[52]


[edit] Popular culture
The first major film appearance of an F-35B was in Live Free or Die Hard (2007). The film used a combination of a full-scale model and CGI[53][54] to dramatize its hovering ability using the lift fan.