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Lockheed Martin F-35 Lightning II

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File:JSF thumb.jpg
The F-35 Joint Strike Fighter

The F-35 Joint Strike Fighter (JSF) is a fighter plane currently in early development by Lockheed Martin (with partners Northrop Grumman and BAE SYSTEMS.)

The primary customers are the United States armed forces and the United Kingdom (RN and RAF), but the Netherlands, Australia, Turkey, Denmark, Norway, Singapore, Canada, Italy and Israel are also participating in the program.

Design

Design characteristics for the JSF include:

  • Stealth
  • Sensor integration to support precision ammunition
  • Low cost to provide adequate force structure for the armed forces
  • Low maintenance cost once deployed

The JSF (F-35) design is based on the soviet Yakovlev-41 supersonic, VTOL naval fighter-bomber plane. The blueprints were sold by the cash-strapped Yakovlev bureau in the early 90's. The USA refined the plans previously made by Yakovlev for a land-based STOL variant dubbed Yak-141 into the F-35. The soviet's two small vertical lift jet engines were thrown out, while Rolls-Royce developed a new powerplant, based on the soviet swiveling-tailpipe design, which could also spin a large, horizontal central fan for cold lift thrust. Other than that, the Yak-141 shape changed relatively little, mostly to boost stealth capabilities and incorporate hidden weapons bays. Internally a lot has been changed, but structurally and with regards to electronics, the plane was essentially redesigned.

The JSF planes are being constructed in three different variants to suit the needs of various users — a conventional take-off and landing aircraft (CTOL) for the U.S. Air Force; a carrier based variant (CV) for the U.S. Navy; and a short take-off and vertical landing (STOVL) aircraft for the U.S. Marine Corps and the Royal Navy.

Manfacturing responsibilites

  • Lockheed Martin Aeronautics (Prime Contractor)
    • Final assembly
    • Overall system integration
    • Mission system
    • Forward fuselage
    • Wings
  • Northrop Grumman
    • 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)

Program History

The Joint Advanced Strike Technology (JAST) program was created in 1993 as a result of a 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 a common family of aircraft to replace several aging U.S. and UK aircraft of which the JSF is one such example.

The JSF is a multi-role attack and fighter aircraft designed to replace the aging F-16 Fighting Falcon, F/A-18 Hornet, A-10 Thunderbolt II, F-111 Raven, Sea Harrier, Harrier GR7/GR9 and AV-8B Harrier jets. It will complement the USAF's high-end F/A-22 Raptor air superiority fighter and the U.S. Navy's F/A-18E/F Super Hornet aswell as Europe's Eurofighter.

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. The construction contract 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, U.S. Department of Defense 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. While Boeing adopted the direct lift system, as in the Harrier, the X-35 generates vertical thrust through the use of the Rolls Royce LiftFan and a thrust-vectoring exhaust nozzle. The LiftFan alone generates 18,000 lbf of thrust, compared to the 21,500 lbf thrust of the Harrier's Pegasus engine. This method has the additional benefit of lowering environmental effects during (primarily) landing, where the thermal effects on for example a carrier deck are greatly reduced.

Analysis of JSF Program

Critics of the program maintain that the JSF suffers from ill-defined design goals; that it has insufficient internal fuel and weapon capacity to make a capable replacement for dedicated bombing aircraft; that its inability to supercruise limits it as an air defence platform, and that it is almost certain to suffer lengthy development delays and cost over-runs — 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. Several nations, however, 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 aircraft 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 aren't being allowed during the JSF development.

In 2004, it emerged that the JSF was indeed suffering development delays and cost blowouts, with the total projected cost of the program rising 23 percent to $244 billion. The major technical problem that was the STOVL F-35B variant's mass, which was reported to be 8 percent over the target level (over 2200 pounds), which meant that the plane was projected as not being able to meet performance requirements. The Air Force CTOL F-35C variant and the Navy carrier-based variant were both within weight limits, but the F-35B was to be requested by the U.S. Marine Corps and the Royal Navy.

Lockheed Martin eventually solved the weight issues, shedding over a ton, and adding thrust. Several steps were taken to achieve this weight reduction, including reducing the thickness of the aircraft's skin, reducing the size of the weapons bay and vertical tails, redesigning the wing-mate joint, portions of the electrial system, and the portion of the aircraft immediately behind the cockpit, and lastly, rerouting some thrust from the roll-post outlets to the main nozzle. The smaller weapons bay will mean that the F-35B cannot carry Mark 84 2,000lb bombs, but this is typically not necessary in the envisioned close air support role.

USAF has elected to buy several wings (representing "hundreds") of the F-35B, as a result. This would seem to guarantee availability of the F-35B for the Marine Corps and the Royal Air Force. The USAF variant of the F-35B may contain enough changes to constitute a new variant. Changes may 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 refuelling system.

Some of the international partners in the project have also become somewhat skittish, with Norway reportedly considering switching their purchase to the Eurofighter Typhoon or Saab Gripen because Norwegian industry had not been offered substantial enough involvement.

The Australian government and defence establishment has remained solidly behind the project. However, a number of concerns about the state of the project have been raised in various media outlets. Firstly, the delays in the schedule 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-18 fighters. The cost blowouts have also raised worries about the fleet's affordability. There has been considerable annoyance about the fact that the Australian planes will be less stealthy than the American versions, which, combined with concerns about the plane's short range, lack of supercruise and unproven dogfighting capabilities, have led to worries about its suitability to replace both the F-18 and F-111.

One important development has been the emergence of a USAF requirement for the STOVL variant, the F-35B. The STOVL variant had been viewed as the most likely victim of cost-cutting measures, however the USAF commitment seems to guarantee the aircraft that the USMC, Royal Navy, 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.

Variants

  • F-35A: conventional land-based version for USAF (potentially RAF)
  • F-35B: STOVL for USMC, RAF and RN (potentially USAF)
  • F-35C: carrier-based version for USN (potentially RN)

While all three versions had an initial slate of intended users, the situation is now somewhat fluid. With real-world performance of the Harrier being seen as positive, USAF is considering the F-35B. The Royal Navy is considering ordering the F-35C variant for its large CVF carriers.

  • Reportedly, versions for some countries other than the U.S. and U.K. may be subject to some export restrictions and be equipped with different mission systems. What equipment would be changed, and the difference in capabilities is not known.

Characteristics

  • Powerplant:
  • Size:
    • Length: 15.47 m
    • Height: 5.28 m
    • Wingspan: 10.05 m
    • Wing area: F-35A and F-35B: 42.7 m²; F-35C: 57.6 m²
  • Weight:
    • Empty: 12,010 kg
    • Normal Takeoff: 19,000 kg (?)
    • Maximum: 22,680 kg
  • Speed:
    • Maximum: Mach 1.7 at altitude,
  • Ceiling: about 15 km.
  • Range:
    • Operational radius: 1000 km (I assume this is without drop tanks, as including them would make it less stealthy)
    • Ferry: ? km
  • Wing Loading: F-35A: 446 kg/m² at 19,000 kg
  • Thrust/weight ratio: F-35A: 6.2 N/kg at 19,000 kg
  • Armament:
  • Cost: planned costs, in millions of 1994USD: F-35A: 28, F-35B: 35, F-35C: 38
  • First flight: 2000
  • In service date: expected to be 2008–2010
  • Users: USA (USAF, USN, USMC); UK (RAF, RN); others

See also

Further reading

  • Spick, Mike (2002), The Illustrated Directory of Fighters. Salamander ISBN 1-84065-384-1
Related content
Related Development
Similar Aircraft
Designation Series

F-21 - F-22 - YF-23 - F-35
X-32 - X-33 - X-34 - X-35 - X-36 - X-37 - X-38

Related Lists List of military aircraft of the United States -

List of fighter aircraft - List of experimental aircraft

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