The Lockheed Martin's F-35 multi-role fighter (also known as the Lightning II) was a contender for the Joint Strike Fighter (JSF) program, which was intended to replace existing aircraft types with a common fighter. The JSF concept was introduced by the US Air Force. Aim of this program was to combine conventional fighter aircraft for the Air Force, catapulted ship-borne aircraft for the US Navy and short take-off-and-vertical-landing fighter for the US Marine Corps.
The Lockheed Martin's proposed aircraft was previously known as the X-35 and it won competition against the Boeing X-32. From 1997 its development has been shared with Northrop Grumman and BAE Systems. The first X-35A prototype was rolled out in June 2000 and made its maiden the same year. Development of this aircraft was principally funded by the USA, with the UK and other partner governments providing additional funding. It is expected to enter service in 2011. US military plans to obtain over 2 440 of these aircraft of all types. These will replace the AV-8B, A-10, F-16 and F/A-18. However due to cost overruns it is likely that fewer new aircraft will be obtained.
The generic F-35 has a configuration similar to that of Lockheed Martin's own F-22 design, however it is slightly smaller and has one engine. Aircraft uses stealth technology, which makes it difficult to detect. It is one of the most advanced forth-generation fighter in the world.
Two different engines were developed for this multi-role fighter, the Pratt & Whitney F135 and secondary General Electric/Rolls-Royce F136 afterburning turbofans. The last mentioned is used on the STOVL aircraft. The Lightning II is capable of cruising at supersonic speeds.
The F-35 multi-role fighter can perform on air defense missions, close air support and tactical bombing. Aircraft is armed with internally mounted GAU-22/A four-barrel 25-mm cannon. It will also carry up to two air-to-air missiles or two air-to-ground weapons in internal weapon bay. These could be AIM-120 AMRAAM, AIM-132 ASRAAM, JDAM, JSOW, Brimstone, WCMD, MBDA Meteor. More missiles, bombs or fuel tanks can be attached to external hardpoint. Wing tip pylons can also carry AIM-9X Sidewinders. It is worth mentioning that external weapons are carried at the expense of being more detectable by radar.
Key systems include a multi-function active, electrically-scanned array that combines radar, electronic warfare and communications functions and a conformal array imaging IR sensor. Data from the various sensors is fused on the pilot's advanced helmet-mounted display system.
Aircraft is proposed in three main variants. These share about 80% of their parts to keep development and production costs low. It also requires less logistic support.
F-35A conventional take-off and landing aircraft. It is a land-based model for the USAF;
F-35B short take-off and vertical landing aircraft. This model is being developed for the USMC, RAF and RN. Connected to the engine via a drive shaft, a Rolls-Royce lift fan behind the cockpit provides around half the thrust required for hovering flight. The lift fan results in lower power settings, and cooler exhaust temperatures and velocities;
F-35C carrier-based aircraft. It is the US Navy's variant, which features a larger wing and control surfaces (fin & elevator) than the other variants. It will be fitted with ailerons, a strengthened landing gear, arrestor hook and a reinforced airframe to absorb catapult launches and arrested landings. Both Royal Navy and US Navy X-35B/Cs will have folding wings.