F-35 Lightning II

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F-35 Lightning II

The first of 15 pre-production F-35s

Type Multirole fighter

Manufacturer Lockheed Martin AeronauticsNorthrop GrummanBAE Systems

Maiden flight Late 2006 (scheduled)

Introduced 2011 (scheduled)

Status Under development/pre-production

Primary usersUnited States Air Force

United States Navy

United States Marine CorpsRoyal Navy

Produced 2003-date

The F-35 Lightning II — descended from the X-35 of the Joint Strike Fighter (JSF) program — is asingle-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 UnitedKingdom, and other partner governments. It is being designed and built by an aerospace industry teamled by Lockheed Martin and major partners BAE Systems and Northrop Grumman. Demonstratoraircraft flew in 2000;[1] first flight of production models is expected in late 2006.[2]

Requirement

Original F-35 Joint Strike Fighter Logo

F-35 Lightning II/JSF Logo

The JSF program was created to replace various aircraft while keeping development, production, andoperating costs down. This was pursued by building three variants of one aircraft, sharing 80% of theirparts:

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 theU.S. Marine Corps (USMC) AV-8 Harrier IIs and F/A-18 Hornets, and Royal AirForce (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 othernations 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 thebulk has been underwritten by the United States.[3]

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[3]. Level 2 partners areItaly, 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; andDenmark, US$110 million. The levels generally reflect the financial stake in the program, the amount oftechnology transfer and subcontracts open for bid by national companies, and the priority order in whichcountries can obtain production aircraft. Israel and Singapore have also joined as Security CooperativeParticipants.[4]

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

United Kingdom participation

Main article: Joint Combat Aircraft

The British government signed on early to the JSF effort, but its officials became increasingly frustratedby U.S. refusal to hand over sensitive technologies that would allow the UK to maintain and upgrade itsfighters without U.S. involvement. For five years, British officials sought an ITAR waiver to securegreater technology transfer. This request, which has the blessing of the Bush administration, has beenrepeatedly blocked by U.S. Representative Henry Hyde, who says that the UK needs to tighten its lawsprotecting against the unauthorized transfer of the most advanced U.S. technology to third parties.[5]

Matters came to a head when BAE Systems CEO Mike Turner complained that the U.S. had denied hiscompany access to the aircraft's source code. On 21 December 2005, an article in the Glasgow Heraldquoted the chairman of the House of Commons Defence Select Committee as saying "the UK mighthave to consider whether to continue in the program" if no access were granted.[6] Lord Drayson,Minister for Defence Procurement, took a firmer stance during a March 2006 visit to Washington: "Wedo expect the software technology transfer to take place. But if it does not take place we will not be ableto purchase these aircraft," and he said there was a 'Plan B' if the deal fell through.[7] This may have beenthe development of a navalized Typhoon.[8]

On May 27, 2006, President George W. Bush and Prime Minister Tony Blair announced that "Bothgovernments agree that the UK will have the ability to successfully operate, upgrade, employ, andmaintain the Joint Strike Fighter such that the UK retains operational sovereignty over the aircraft."[9]

Australian participation

In May 2005, the Australian government announced that it would delay its planned 2006 decision onbuying the JSF to 2008, and thus past the term of the present government. Australia, like the UK, hasinsisted it must have access to all software needed to modify and repair aircraft.

Royal Australian Air Force opinion remains strongly in favour of the JSF. However, some mediareports, lobby groups and politicians have raised doubts that the aircraft will be ready in time to replacethe 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 betterrange, dogfighting capability, and supercruise at a cost that may not be much more than the F-35[10] —claims that as of July 2006 are being examined in a parliamentary inquiry.[11] In a statement released inearly August 2006, Australian Defence Minister Dr. Brendan Nelson revealed that whilst the F-35 stillhad governmental support, Australia is starting to investigate other possible aircraft should the F-35prove to be unfeasible. Whilst not revealing which aircraft the Australian government is considering, hedid rule out the F-22 from Australian considerations.[12] In October 2006 the deputy chief of the AirForce, Air Vice Marshal John Blackburn, publicly stated that the RAAF had ruled out the purchase ofinterim strike aircraft to cover any delays to the F-35 program and believed that the F-35 was suitable.[13]

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 waschosen. DoD photo

The Joint Strike Fighter evolved out of several requirements for a common fighter to replace existingtypes. 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 toLockheed Martin, whose X-35 beat the Boeing X-32. DoD officials and the UK Minister of DefenceProcurement said the X-35 consistently outperformed the X-32, although both met or exceededrequirements.

On 19 February 2006, the first F-35 (USAF version) was rolled out in Fort Worth, Texas. The aircraftwill 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 testscompleted on 18 September after a static run with full afterburner. The engine runs were the first timethat the F-35 was completely functional on its own power systems. [14]

Naming

On 7 July 2006, the U.S. Air Force officially announced the name of the F-35: Lightning II,[15] in honorof Lockheed's World War II-era twin-prop P-38 Lightning and the Cold War-era jet English ElectricLightning. English Electric's aircraft division was incorporated into BAC, a predecessor of F-35 partnerBAE 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-22Raptor.

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 andsleeker one-engine sibling of the two-engine F-22. The exhaust duct design was inspired by the GeneralDynamics Model 200, a 1972 VTOL aircraft designed for the Sea Control Ship.[16] Lockheed had ateaming relationship with the Yakovlev Design Bureau on their bid for the Joint Advanced StrikeTechnology competition.[17] This has fueled speculation that the overall design of the F-35 was heavilyinfluenced by the Yakovlev Yak-141 'Freestyle', however, the two aircraft are very different.

Stealth technology makes the aircraft hard to detect as it approaches short-range tracking, although itsrear is much more easily spotted.[citation needed]

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 improveidentification and weapon delivery, and to relay information quickly to othercommand and control (C2) nodes;

Low life-cycle costs.

Although helmet-mounted display systems have already been integrated into some fourth-generationfighters like the Swedish-manufactured JAS 39 Gripen, the F-35 will be the first modern combat aircraftin which helmet-mounted displays will replace a heads-up display altogether.[18]

F-35A

The F-35A is the smallest, lightest version, and is intended primarily to replace the U.S. Air Force'saging F-16 Fighting Falcons and A-10 Thunderbolt IIs. This is the only version with an internal gun, theGAU-12/U. This 25 mm cannon is an upgrade from the 20 mm M61 Vulcan carried by USAF fighterssince 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 firstoperational short-takeoff / vertical-landing fighter. The Royal Navy will use this to replace its SeaHarrier FA2s and the RAF's GR9s. The U.S. Marine Corps will use the F-35B to replace both its AV-8BHarriers and F/A-18 Hornet fighters with a design similar in size to the Air Force F-35A, trading fuelvolume for vertical flight systems. Like the Harrier, guns will be carried in a pod. Vertical flight is by farthe 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 aninnovative shaft-driven Lift Fan, patented by Lockheed Martin and developed by Rolls-Royce.[19]

Somewhat like a turboprop embedded into the fuselage, engine shaft power is diverted forward via aclutch-and-bevel gearbox to a vertically mounted, contra-rotating lift fan located forward of the mainengine in the center of the aircraft. Bypass air from the cruise engine turbofan exhausts through a pair ofroll-post nozzles in the wings on either side of the fuselage, while the lift fan balances the vectoringcruise nozzle at the tail.

In effect, the F-35B power plant acts as a flow multiplier, much as a turbofan achieves efficiencies bymoving unburned air at a lower velocity, and getting the same effect as the Harrier's huge, butsupersonically 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 theharmful 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. UnlikeBoeing'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 waslater converted into the X-35B), and the larger-winged X-35C.[20] Both the Boeing X-32 and X-35power plants were derived from Pratt & Whitney's F119, with the STOVL variant of the latterincorporating a Rolls-Royce Lift Fan module.

Arguably the most persuasive demonstration of the X-35's capability was the final qualifying JointStrike Fighter flight trials, in which the X-35B STOVL aircraft took off in less than 500 feet, wentsupersonic, and landed vertically.[21]

F-35C

The Naval F-35C variant will replace the F/A-18A, -B, -C, and -D Hornets, which replaced subsonic butlong-ranged attack types such as the A-7 Corsair and A-6 Intruder. It will also serve as a stealthycomplement to the F/A-18E/F Super Hornet. It will have a larger, folding wing and larger controlsurfaces 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 fuelcompared 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.[22]

Directed-energy weapons

Directed-energy weapons may be installed in conventional takeoff F-35 Lightning IIs, whose lack of adirect 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.[23] Some concepts, including solid state lasers and high-power microwavebeams, may be nearing operational status.[24]

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 fighteraircraft in U.S. military service. Joint Strike Fighter critics[Please name specific person or group ] say that like theaircraft it is replacing, it has insufficient range to replace dedicated bombers; and as primarily a strikeplatform, its inability to supercruise limits it as an air defense platform, and as a new aircraft, that it isalmost certain to suffer cost overruns and lengthy development delays.[citation needed] Indeed, through 2004,the JSF's total projected cost had risen 23% to US$244 billion, and as of April 2006 the Pentagon isprojecting the budget to rise to US$276.4 billion.[citation needed]

A Reuters report in 2005 said that the Pentagon was seeking to cancel the Air Force version. This wouldsee the Air Force adopt the larger Navy version.[25] 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, arevocally skeptical about the F-35's capacity to carry out that role. They point to the claim duringprocurement of the F-16 that it would replace the A-10, which it did not, and to the F-35's similarshortcomings for the close air support mission, specifically its small gun and ammunition capacity, andthe tight constraints on the number and variety of bombs and missiles it can carry in its stealthconfiguration -- not an issue when carrying external stores in a non-stealthy A-10-like configuration.[26]

Its defenders say the JSF was never intended to replace bombers or be an air defense platform, and theysay a thorough requirements definition process with years of analysis and international participation hasmitigated cost and schedule concerns. The potential solid state laser is also offered as an advantage forthe close air support role, since aerial refueling would essentially also rearm the laser, which could beused even with enemy ground forces located too close to friendly ground forces for employment ofexplosive armaments.

Proponents say the multi-role design philosophy has been proven in combat by the F-16 Fighting Falconand the F/A-18 Hornet, and point to several nations, mainly F-16 and F/A-18 users, that have committedsubstantial sums to become minority partners in the JSF manufacturing team. They say that even withoutsubstantial performance advances over existing aircraft, the F-35's stealthiness and information warfaretechnology make it an enticing product.

The program's advocates see the JSF's joint-development concept as an opportunity to break out of thedecades-old pattern of U.S. military aircraft procurement, allowing commonality and savingdevelopment and operating costs. This follows the philosophy behind the SEPECAT Jaguar and PanaviaTornado international development programs. Accordingly, JSF is the first U.S. aircraft program toconsider cost as an independent variable. Unlike earlier programs in which extra features alwaysboosted 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 tooperate 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 thrustand 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.[27]

The smaller weapons bay will return the F-35B to its original 2 × 1000 lb (450 kg) internal-weaponscarriage. This is not expected to hinder close air support missions, which are likely to take place afterenemy air defenses are down, but may make the "B" variant different from the other two, boostingcosts.[citation needed]

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

Speculated USAF STOVL Purchase

As costs grow, there have been rumors about canceling the F-35B variant. However, U.S. operations inAfghanistan 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 bythe USMC, RN, and RAF.[citation needed]

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 propulsionsystem 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

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 factsheets.

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 F135or 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[28] (? m/s) Wing loading: 91.4 lb/ft² (446 kg/m²) Thrust/weight: 0.968 with full fuel, 1.22 with 50% fuel

F-35A and F-35C Armament

Armament

1 × GAU-12/U 25 mm cannon — slated to be mounted internally with 180 roundsin 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-120AMRAAM, 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 Cmodels; two 1000 lb weapons in the B model) in the bomb bays. These could beAMRAAM, the Joint Direct Attack Munition (JDAM) — up to 2,000 lb (910 kg),the Joint Standoff Weapon (JSOW), Small Diameter Bombs (SDB) — amaximum of 4 in each bay, the Brimstone anti-armor missiles, Cluster Munitions(WCMD) and High Speed Anti-Radiation Missiles (HARM). The MBDA Meteorair-to-air missile is currently being adapted to fit internally in the missile spotsand may be integrated into the F-35.

At the expense of being more detectable by radar, many more missiles, bombsand fuel tanks can be attached on four wing pylons and two wingtippositions[citation needed]. The two wingtip pylons can only carry short-range air-to-airmissiles (AIM-9's), while the Storm Shadow and Joint Air to Surface Stand-offMissile (JASSM) cruise missiles can be carried in addition to the stores alreadyintegrated. An air-to-air load of 12 AIM-120s and 2 AIM-9s is conceivable usinginternal and external weapons stations (as well as a configuration of six twothousand pound bombs, 2 AIM-120s, and 2 AIMs), but highly unlikely in anyoperational scenario.

Manufacturing responsibilities

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

Lockheed Martin Aeronautics (prime contractor)o Final assemblyo Overall system integrationo Mission systemo Forward fuselageo Wingso Flight controls system

Northrop Grummano Active Electronically Scanned Array (AESA) radaro Center fuselageo Weapons bayo Arrestor gear

BAE Systemso Aft fuselage and empennageso Horizontal and vertical tailso Crew life support and escapeo Electronic warfare systemso Fuel systemo Flight Control Software (FCS1)