F-35 Joint Strike Fighter

The F-35 Joint Strike Fighter (JSF) is a military fighter aircraft designed by the USA and the United Kingdom. It is intended to replace the current generation of strike fighters, particularly the vertical take off and landing Harrier jump jets : the AV-8 Harrier II (US), Harrier GR7/9 (UK), and the Sea Harrier (UK), along with the conventional A-10 Thunderbolt II, F/A-18 Hornet and the F-16 Fighting Falcon. It is set to be a multi-role strike fighter (a plane with a strong emphasis on close air support and tactical bombing as well as being capable of air-to-air combat), currently in production with Lockheed Martin, along with partners Northrop Grumman and BAE Systems.

Three variants are envisioned: the conventional takeoff and landing (CTOL) F-35A for the U.S. Air Force (USAF) and the RAF; the Advanced Short Take-Off Vertical Landing (ASTOVL) F-35B for the U.S. Marine Corps (USMC) and the Royal Navy (RN); and the carrier-based (CV) F-35C for the U.S. Navy (USN). The USAF is considering the F-35B, and the Royal Navy is considering ordering the F-35C variant for its large CVF Future Carrier programme.

The F-35, expected to be ready for service in 2008, is scheduled to begin replacing Marine Corps AV-8B Harrier and F/A-18s in 2009, and the USAF A-10 Thunderbolt II and F-16 in 2010.

International participation

The primary customers are the armed forces of the United States (USAF, USN, and USMC) and the United Kingdom (RAF and RN). There are three levels of international participation for the eight countries contributing to the program. The United Kingdom is the sole level I partner, contributing a little over $2 billion. Level II partners are Italy and the Netherlands, contributing $1 billion and $800 million respectively. At level III are Turkey ($175 million), Australia ($144 million), Norway ($122 million), Denmark ($110 million), and Canada ($100 million). The levels generally indicate the financial stake in the program, the level of technology transfer and subcontracts open for bid by national companies, and the general order in which countries can obtain production aircraft. Israel and Singapore have also joined as Security Cooperative Participants.

The biggest international partner, the United Kingdom, has invested two billion in development funding for the project. Britain has also worked for five years for an ITAR waiver to allow greater technology transfer associated with the project. The effort, backed by the Bush administration, has been repeatedly blocked by U.S. Congressman Henry Hyde because of his concern about potential technology transfer to third countries.

The CEO of BAE Systems, the British contractor on the plane, has complained that the U.S. has not given the UK (and his company) access to the crucial source code of the plane's software, thus making it impossible for the UK to maintain and modify the JSF independently. At a news conference at the Paris Air Show, he has even suggested that the UK may withdraw from the program unless additional access is granted, though analysts consider this unlikely . On 21 December 2005 an article was published in the Glasgow Herald saying that MPs viewed as "unacceptable" the U.S. refusal to grant access to the source code. The article quotes the chairman of the Commons Defence Select Committee as saying that unless the UK receives assurances of access to the software information, "the UK might have to consider whether to continue in the programme". Nonetheless, UK production commenced on 2 February 2006.

International participants have at various times been cited as considering withdrawing from the JSF Program in favor of other aircraft such as Eurofighter Typhoon, Gripen or Rafale. Perceived inequitable sharing in JSF production is most often cited as the reason for considering withdrawal, rather than cost or performance concerns.

Program history

The Joint Advanced Strike Technology (JAST) program was created in 1993 as a result of a United States Department of Defense (DoD) Bottom-Up-Review. The major tactical aviation results of the review were to continue the ongoing F-22 and F/A-18E/F programs, cancel the Multi-Role Fighter (MRF) and the A/F-X programs, curtail F-16 and F/A-18C/D procurement, and initiate the JAST Program.

The JAST program office was established on January 27, 1994. It was established to define and develop aircraft, weapon, and sensor technology that would support the future development of tactical aircraft. The final goal was to replace several aging U.S. and UK aircraft with a common family of aircraft, of which the JSF is one example.

It will complement the USAF's high-end F-22 Raptor air superiority fighter and the USN's F/A-18E/F Super Hornet as well as Europe's Eurofighter.

Concept demonstration

The contract for development of the prototypes was awarded on 16 November 1996 to Lockheed Martin and Boeing, under which each was to produce two aircraft which were to demonstrate Conventional Take Off and Landing (CTOL), carrier take off and landing (CV version), and Short Take Off and Vertical Landing ( STOVL).

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

System development and demonstration

The construction contract, System Development and Demonstration (SDD), was awarded on 26 October 2001 to the Lockheed Martin X-35, beating the Boeing X-32. The first planes are expected to enter service in 2008. Announcing the decision, DoD officials and the UK Minister of Defence Procurement said that while both aircraft met or exceeded requirements, the X-35 outperformed the Boeing aircraft consistently. This dominance can only have been achieved by Lockheed's method of STOVL flight; in fact, the decision is said to have clinched the contract.

On February 19, 2006, the first F-35 (USAF version) was rolled out in Fort Worth, Texas by Lockheed Martin. The aircraft will undergo extensive ground testing and then flight tests in the fall. [1]

Design

The X-35 powerplant uses the highly complex Remote Shaft-Driven Lift Fan concept, where (in the STOVL mode) LP turbine power is diverted, forward via a clutch-and-bevel gearbox, to a vertically mounted, contra-rotating, remote fan. Bypass air exhausts through a pair of roll post nozzles on either side of the fuselage, whilst both the remote fan and the LP turbine streams exhaust through thrust vectoring nozzles. In effect, the X-35 power plant acts as a flow multiplier and consequently has more than sufficient thrust for lift operations. This lift concept has the additional benefit of lowering environmental effects during (primarily) landing, where the thermal effects on, for example, a carrier deck are greatly reduced.

The rival Boeing X-32 adopted the relatively elegant Direct Lift System, where the engine exhaust gases were redirected to thrust vectoring nozzles to achieve lift during a STOVL landing. However, even though the fan was oversized and throttle-pushed, it had insufficient thrust for lift. Because of the large engine airflow, the X-32 required a huge front air intake, compromising the aesthetics of the aircraft's aerodynamics. According to critics, Boeing designed an airplane "only its mother would love", in direct violation of the maxim "if it looks good, it flies good".

Both the X-32 and X-35 power plants were derived from Pratt & Whitney F119, with the STOVL variant of the latter incorporating Rolls Royce Lift Fan module.

Note also that elements of the JSF design were pioneered by the F-22. The airframe appears quite similar to the F-22, albeit somewhat reduced in size, and only has a single engine.

Primary factors in the design included:

• Stealth technology capability
• Integrated avionics and sensor fusion - This allows information from off board sensors to be combined with those on-board the aircraft, to enhance the pilot's situational awareness and improve precision weapon delivery.
• Low construction cost
• Low maintenance cost

Advanced weapons

The direct lift fan assembly, when not installed, provides approximately 100 ft³ of space , along with more than 27,000 hp (20 MW) available for electrical power production . This has made directed-energy weapons possible for the F-35. Some of these designs, including solid state lasers and high-power microwave beams, are thought to be nearing operational status .

Possible reduction to two primary variants

Experts predicted in 2005 that the JSF program's Conventional Take-off and Landing [CTOL] F-35A variant may be canceled by acting U.S. Deputy Defense Secretary Gordon England. This would not immediately save money in the program as the preproduction F-35A prototypes are already under construction, but long term, this cancellation could free up enough money to ensure that the program's F-35B and F-35C variants survive in the United States' tightening defense budget. Since then a flurry of lobbying from the JSF contractors, the Air Force, and representatives from the United Kingdom has convinced Secretary England and the DoD to stick with the 3-variant program.

Had such a cancellation occurred, the United States Air Force would stay in the program by purchasing either the STOVL F-35B for its close air support capabilities, the F-35C for its greater range, or a combination of the two. However, buys of these variants would likely be less than the 1000+ CTOL originally envisioned by the Air Force, as both variants cost more. This would have been a boon for A-10 and F-16 supporters, since those aircraft would probably be retained longer to compensate.

Export partners who were already wary of the JSF's rising costs showed some concern over a potential CTOL cancellation. Even the UK, which has no CTOL JSF requirement, lobbied to preserve that variant in order to keep costs of the others down. In the long run, the F-35B and F-35C should still be appealing to at least some of the international market, being the only fifth-generation program with a STOVL variant for countries in need of Harrier replacements.

Analysis of JSF program

Critics of the program maintain that the JSF suffers from ill-defined design goals; that it has insufficient range to make a capable replacement for dedicated bombing aircraft; that its inability to supercruise limits it as an air defense platform, and that it is almost certain to suffer lengthy development delays and cost overruns; meaning that interim types will have to be purchased to fill the gap between the end of useful life of existing fleets and the introduction of the JSF. However, it is important to note that the multi-role design philosophy has been tested and proven in combat over a period of at least 25 years, with successful types like the F-16 Fighting Falcon and the F-18 Hornet. Several nations, mainly current F-16 and F-18 users, already have sufficient confidence in the design to have committed substantial sums to become minority partners in the JSF manufacturing team.

The program's advocates see the JSF as an opportunity to break out of the decades-old pattern of U.S. military aircraft procurement: instead of a traditional per-service design approach, the JSF is being developed jointly by the Air Force, Navy and Marine Corps. This allows an estimated 80% commonality between the JSF variants for the different services, lowering procurement and service costs. This follows to a degree the philosophy behind the SEPECAT Jaguar and Panavia Tornado international development programs, the latter being called a multi-role combat aircraft (or MRCA) prior to service entry. Additionally, JSF is the first U.S. aircraft program to consider cost as independent variable (CAIV). In earlier programs the aircraft cost has been a dependent variable; additional features have always increased the aircraft cost. Such design changes are not being allowed during the JSF development.

Non-vehicle differentiator

A ground-based information system (the Autonomic Logistic Information System, or ALIS), built by Lockheed Martin Simulation Training and Support, is intended to make the JSF less expensive to operate and maintain.

Cost/weight issues

Through 2004 the JSF's total projected cost had risen 23% to $244 billion. The major technical problem was the F-35B variant's mass, which was reported to be 2,200 pounds, or 8%, over the target, which meant that the STOVL plane was projected to miss performance requirements.

Lockheed Martin eventually solved the weight problem by adding engine thrust and shedding over a ton by thinning the aircraft's skin; shrinking the F-35B 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.

The smaller weapons bay will limit F-35B to 2 x 1000 lb (450 kg) weapons internally (this is as originally planned, for the 2 x 2000 lb requirement was added later). This is not expected to be a hindrance in close air support missions, which are likely to take place after enemy air defenses are down. Still, this 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 make for some interesting weapons certification work. The JSF has yet to drop a bomb, fire a missile, or fire a gun airborne—no demonstrations of weapons delivery capability were done during the "winner take all" fly off prior to contract award.

USAF STOVL purchase

The JSF program is not immune from interservice politics. A recurring theme has been the potential for a USAF requirement for the F-35B. The STOVL variant had been viewed as the most likely victim of cost-cutting measures; however, a USAF "commitment" seems to guarantee the aircraft that the USMC, RN, and RAF need. It is understood that the U.S. military's experience in Afghanistan has highlighted the importance of more flexible assets in the close air support role.

The USAF has investigated buying up to three wings (representing 216 examples) of the F-35B. For a time it appeared that the hypothetical USAF variant of the F-35B would contain enough changes to constitute a new variant (an F-35D). Changes were to include differences in the 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), or changes to the in-flight refueling system. However, due to opposition from people involved with the program, and the associated cost of developing a fourth variant, the USAF version would likely be identical to the USMC/RN F-35B specification.

Australian Participation

In May 2005 the Australian government announced that it was delaying a final decision on the JSF from the initial 2006 decision date to 2008 (and thus past the term of the present government). There are some concerns amongst Australian media, lobby groups and politicians, who have raised doubts that the aircraft will be ready in time to replace the aging Australian air force fleet of F-111 ground attack planes and F/A-18 fighters.

Concerns have been raised over cost efficiency, dog fighting capability, short range and lack of supercruise. The government also claims that the cost of purchasing mature F-22s may not be that much greater than the JSF.

It should be noted on this claim that Jane’s Defence weekly recently (in 2005) put the value of an F-22 at $151 million dollars U.S., rising to $200 million if upgrades to approach the F-35's air to ground targeting performance were included. At a projected price of $45 million U.S. (2003 dollars), the F-35 is three to four times cheaper than the F-22. Therefore, there would have to be a very significant cost blowout in the F-35 program for the F-22 to become better value for money.

Specifications (F-35 Joint Strike Fighter)

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 (12,000 kg)
• Loaded weight: 42,000 lb (19,000 kg)
• Maximum gross takeoff weight: 50,000 lb (23,000 kg)
• Powerplant: 1× Pratt & Whitney F135 afterburning turbofan, 37,100 lbf (165 kN)
  • Secondary (High Performance), discontinued in current budget proposal: 1x General Electric/Rolls-Royce F136 afterburning turbofan 178 kN thrust
  • Lift fan (STOVL): 1x Rolls-Royce Lift System in conjunction with either F135 or F136 power plant 18,000 lbf (80 kN) thrust) each

Performance

• Maximum speed: Mach 1.8 (1,200 mph, 2,000 km/h)
• Cruise speed: Mach (mph, km/h)
• Range: 620 miles (1,000 km)
• Service ceiling: 48,000 ft (15,000 m)
• Climb rate: 40,000 ft/min (200 m/s)
• Wing loading: 91.4 lb/ft² (446 kg/m²)
• Thrust/weight: 0.63:1

Armament

• 1x GAU-12/U 25 mm cannon. Mounted internally with 180 rounds in the F-35A, fitted as an external pod with 220 rounds in the F-35B/C
• In two bomb bays (current planned weapons for integration) - One AIM-120 AMRAAM, AIM-9X Sidewinder or AIM-132 ASRAAM internally on the inside of the bomb bay door and one air-to-air or air-to-ground weapon in each bomb bay. These could be AMRAAM, the Joint Direct Attack Munitions (JDAM) - up to 2,000 lb (910 kg), the Joint Stand off 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, more missiles, bombs and fuel tanks can be attached on four wing pylons and two wingtip positions. The latter can only take short-range air-to-air missiles, 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.

Other

• Cost: (in millions US$):
  • F-35A: 45
  • F-35B: 60
  • Costing as per Asia Pacific Defence Reporter, September 2005.
  • F-35C: 55
• First flight - X-35 demonstrator: 2000
• Expected first flight F-35A - September 2006
• In-service date: expected to be 2009 through 2012. The reason for this is that the A will be brought into service first followed by the B. The C will be in service in 2012.

Manufacturing responsibilities

• Lockheed Martin Aeronautics (prime contractor)
  • Final assembly
  • Overall system integration
  • Mission system
  • Forward fuselage
  • Wings

• Northrop Grumman
  • Active Electronically Scanned Array (AESA) radar
  • Center 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)