F-35 Lightning II

2007 Schools Wikipedia Selection. Related subjects: Air & Sea transport; Military History and War

F-35 Lightning II

The first of 15 pre-production F-35s
Type	Multirole fighter
Manufacturer	Lockheed Martin Aeronautics Northrop Grumman BAE Systems
Maiden flight	Late 2006 (scheduled)
Introduced	2011 (scheduled)
Status	Under development/pre-production
Primary users	United States Air Force United States Navy United States Marine Corps Royal Navy
Produced	2003-date

The F-35 Lightning II — descended from the X-35 of the Joint Strike Fighter (JSF) program — is a single-seat, single-engined military strike fighter, a multi-role 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 major partners BAE Systems and Northrop Grumman. Demonstrator aircraft flew in 2000; first flight of production models is expected in late 2006.

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, a conventional takeoff and landing ( CTOL) variant slated to replace U.S. Air Force (USAF) F-16 Fighting Falcons, beginning in 2011.
F-35B, a short-takeoff and vertical-landing ( STOVL) variant slated to replace the U.S. Marine Corps (USMC) AV-8 Harrier IIs and F/A-18 Hornets, and Royal Air Force (RAF)/Royal Navy (RN) Harrier GR7/GR9s beginning in 2012.
F-35C, a carrier-based variant slated to replace U.S. Navy (USN) F/A-18 Hornets (A/B/C/D variants only) beginning in 2012.

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 2006 whether or not to purchase it. Total program development costs, less procurement, are estimated at over US$40 billion, of which the bulk has been underwritten by the United States.

There are three levels of international participation. The United Kingdom is the sole 'Level 1' partner, contributing slightly over US$2 billion, about 10% of the development costs . Level 2 partners are Italy, which is contributing US$1 billion, and the Netherlands, US$800 million. At Level 3 are Canada, US$440 million; Turkey, US$175 million; Australia, US$144 million; Norway, US$122 million; and Denmark, US$110 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 priority order in which countries can obtain production aircraft. Israel and Singapore have also joined as Security Cooperative Participants.

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

This image is not present because of licensing restrictions

The British government signed on early to the JSF effort, but its officials became increasingly frustrated by U.S. refusal to hand over sensitive technologies that would allow the UK 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 that the UK needs to tighten its laws protecting against the unauthorized transfer of the most advanced U.S. technology to third parties.

Matters came to a head when BAE Systems CEO Mike Turner complained that the U.S. 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 program" if no access were granted. 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. This may have been the development of a navalized Typhoon.

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."

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. Australia, like the UK, has insisted it must have access to all software needed to modify and repair aircraft, citing American firms' profiteering on F/A-18 maintenance.

Royal Australian Air Force opinion remains strongly in favour of the JSF. However, some media reports, 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 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 — claims that as of July 2006 are being examined in a parliamentary inquiry. 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. Whilst not revealing which aircraft the Australian government is considering, he did rule out the F-22 from Australian considerations. 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.

JSF Program history

Origins and X-32 vs. X-35

Boeing X-32 (left) and Lockheed Martin X-35 prior to down-select in 2001, where the X-35 was chosen. DoD photo

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.

On 19 February 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 at Edwards Air Force Base in fall 2006.

On 15 September 2006 the first engine run of the F135 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.

Naming

On 7 July 2006, the U.S. Air Force officially announced the name of the F-35: Lightning II, in honour 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 company name for the aircraft that became the F-22 Raptor.

Design characteristics

The F-35A while being towed at the Inauguration Ceremony on July 7th, 2006.

Elements of the F-35 design were pioneered by the F-22 Raptor. The F-35 appears to be a trimmer and sleeker one-engine sibling of the two-engine F-22. The exhaust duct design was inspired by the General Dynamics Model 200, a 1972 VTOL aircraft designed for the Sea Control Ship. Lockheed had a teaming relationship with the Yakovlev Design Bureau on their bid for the Joint Advanced Strike Technology competition. This has fueled speculation that the overall design of the F-35 was heavily influenced by the Yak-141,(In the Aircraft Museum at aerospaceweb.org) however, the two aircraft are very different.

Stealth technology makes the aircraft hard to detect as it approaches short-range tracking, although its rear is much more easily spotted.

Some specific 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;
Low life-cycle costs.

Although helmet-mounted display systems have already been integrated into some fourth-generation fighters like the Swedish-manufactured JAS 39 Gripen, the F-35 will be the first modern combat aircraft in which helmet-mounted displays will replace a heads-up display altogether.

F-35A

The F-35A is the smallest, lightest version, and is intended primarily to replace the U.S. Air Force's aging F-16 Fighting Falcons and A-10 Thunderbolt IIs. This is the only version with an internal gun, the GAU-12/U. This 25 mm cannon is an upgrade from the 20mm M61 Vulcan carried by USAF fighters since the F-104 Starfighter.

F-35B

X-35B lift fan; the VTOL propulsion system is designed and manufactured by Rolls-Royce plc.

The F-35B STOVL aircraft is intended to replace the vertical flight Harrier, which was the world's first operational short-takeoff / vertical-landing fighter. The Royal Navy will use this to replace its Sea Harrier FA2s and the RAF's GR9s. The U.S. Marine Corps will use the F-35B to replace both its AV-8B Harriers and F/A-18 Hornet fighters with a design similar in size to the Air Force F-35A, trading fuel volume for vertical flight systems. Like the Harrier, guns will be carried in a 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 like the AV-8 Harrier, the F-35B uses an innovative shaft-driven Lift Fan, patented by Lockheed Martin and developed by Rolls-Royce. Somewhat like a turboprop embedded into 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 centre 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.

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 also reduces the harmful effects of hot, high-velocity air which can harm runway pavement or an aircraft carrier deck. Though risky and complicated, it was made to work to the satisfaction of DOD officials. Unlike Boeing's entry, the prototype was able to demonstrate a historic flight starting with a short takeoff, transitioning to supersonic flight, and ending with a vertical landing.

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. 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.

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.

F-35C

The Naval F-35C variant will 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 stealthy complement to the F/A-18E/F Super Hornet. It 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, achieving much the same goal as the much heavier Super Hornet. The U.S. Navy plans to purchase 480 JSF.

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 and whose engine provides more than 27,000 hp (20 MW) for electrical power. Some concepts, including solid state lasers and high-power microwave beams, may be nearing operational status.

Analysis of JSF program in United States services

The JSF program was designed to replace the F-16, A-10, F/A-18 and AV-8B fleet of tactical fighter aircraft in U.S. military service. Joint Strike Fighter critics say that like the aircraft it is replacing, it has insufficient range to replace dedicated bombers; and as primarily a strike platform, its inability to supercruise limits it as an air defense platform, and as a new aircraft, 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.

A Reuters report in 2005 said that the Pentagon was seeking to cancel the Air Force version. This would see the Air Force adopt the larger Navy version. Over a year later, no such move had been made.

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 in its stealth configuration -- not an issue when carrying external stores in a non-stealthy A-10-like configuration.

Its defenders say the JSF 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 an advantage for the close air support role, since aerial refueling would essentially also rearm the laser, which could be used even with enemy ground forces located too close to 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/A-18 Hornet, and point to several nations, mainly F-16 and F/A-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 aircraft, 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.

Thrust-to-weight ratio

The F-35B variant was in danger of missing performance requirements because it weighed too much — reportedly, by one metric ton (2,200 pounds) 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.

The smaller weapons bay will return the F-35B to its original 2 × 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.

Speculated USAF STOVL Purchase

As costs grow, there have been rumors about canceling 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 discussed 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 internal cannon (as opposed to the USMC external gun pod), and changes to in-flight refueling.

Specifications (F-35 Lightning II)

X-35C

Some information is estimated.

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 t)
Loaded weight: 44,400 lb (20.1 t)
Max takeoff weight: 60,000 lb (27.2 t)
Powerplant: 1× Pratt & Whitney F135 afterburning turbofan, (43,000 lbf w/AB, 28,000 lbf dry; 191 kN w/AB, 128 kN dry) link Lockheed-Martin media kit fact sheets.
Secondary (High Performance), in development: 1 × General Electric/Rolls-Royce F136 afterburning turbofan > 178 kN thrust
Lift fan (STOVL): 1 × Rolls-Royce Lift System in conjunction with either F135 or F136 power plant 18,000 lbf (80 kN) thrust)

Performance

Maximum speed: Mach > 1.6 (Mach 1.8 est.) (1,200 mph, 1930 km/h)
Cruise speed: Mach (mph, km/h)
Range: ~1200 nautical miles on internal fuel (~2222 km on internal fuel)
Service ceiling: ? ft (? m)
Rate of climb: ? ft/min (? m/s)
Wing loading: 91.4 lb/ft² (446 kg/m²)
Thrust/weight: 0.968 with full fuel, 1.22 with 50% fuel

Lockheed-Martin F-35 statistics summary. (Zip File)

F-35A and F-35C Armament

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.
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 4 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-9's), 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 2 AIM-9s is conceivable using internal and external weapons stations (as well as a configuration of six two thousand pound bombs, 2 AIM-120s, and 2 AIMs), but highly unlikely in any operational scenario.

Manufacturing responsibilities

X-35A being refuelled in-flight by a KC-135 Stratotanker

Lockheed Martin Aeronautics (prime contractor)
- Final assembly
- Overall system integration
- Mission system
- Forward fuselage
- Wings
- Flight controls system
Northrop Grumman
- Active Electronically Scanned Array (AESA) radar
- Centre fuselage
- Weapons bay
- Arrestor gear
BAE Systems
- Aft fuselage and empennages
- Horizontal and vertical tails
- Crew life support and escape
- Electronic warfare systems
- Fuel system
- Flight Control Software (FCS1)