Fort Worth, Texas, is home to Lockheed Martin’s oldest and largest factory as also the place where one of the world’s most technologically advanced and expensive fighter aircraft development programme is evolving. Plagued by delays and cost overruns, the F-35 programme has come under greater focus after the US Government announced possible cuts in the defence budget. Whether or not the programme will recover from the nose-dive needs to be analysed.

The F-35 programme emerged from the US common affordable lightweight fighter project which initially was exclusively an American project initiated in 1993. Joined by UK and others in 1996, it was re-designated as the US joint strike fighter (JSF) programme. The US plan was to develop a single stealth fighter to replace a group of frontline aircraft such as the F-16 Fighting Falcon, the F/A-18 Hornet, A-10 Thunderbolt II and the AV-8B Harrier II. A common design with different variants was visualised to keep development, production and operating costs low. The F-35A was the conventional take-off and landing (CTOL) variant, F-35B the short take-off and vertical landing (STOVL) variant and F-35C carrier-based variant. The F-35A, the smallest and lightest version, was expected to match the F-16 in manoeuvrability but with better capability in respect of stealth, payload, and range on internal fuel, avionics, operational effectiveness, supportability and survivability. Eighty per cent commonality in components among the three variants was also envisaged.

The F-35B was to sacrifice a third of the internal fuel to accommodate the vertical flight system. The US Marine Corps (USMC) was to purchase 340 F-35Bs to replace the F/A-18 and AV-8B. The Royal Air Force (RAF) and the Royal Navy were to induct the F-35B to replace their Harrier GR9s. The UK would initially receive 48 F-35B and final numbers were to be decided later. The Italian Navy would buy 22 between 2014 and 2021. The carrier variant F-35C would feature larger wings for more lift and foldable wings for stowage on or below deck. It would have robust landing gear for arrested landings on carriers and a stronger tail hook for arrestor cable. The USMC was to receive 80 F-35C and the USN 480 F-35Cs. The F-35C was rolled out in July 2009 and is expected to be available in 2014.

Lockheed Martin had claimed that the F-35 would be far better than the existing fighters in air-to-air combat, air-toground engagement, reconnaissance and suppression of air defences and would have better logistics support. It would be the premier strike aircraft past 2040 and second to the F-22 Raptor in air superiority. The contract was awarded to Lockheed Martin in October 2001 after its X-35 beat, the Boeing X-32, primarily on better growth potential. In July 2006, the US Air Force (USAF) named the F-35 as ‘Lightning II’ in honour of Lockheed’s World War II-era twin-prop P-38 Lightning and the English Electric Lightning. Lightning II was also a name for its fighter that was later renamed F-22 Raptor. The US permitted Israel to integrate its own electronic warfare systems including the external jammer pod, its own air-to-air missiles and guided bombs in the internal weapon bays in their variant F-35I. Israeli pilots are scheduled to start training by end 2016. Israel feels that the current stealth features may become redundant in the next ten years and since the aircraft will operate for over 40 years, there is a need for an updated electronic warfare suite.

Features of the Aircraft

The F-35 is essentially a smaller, single-engine lighter version of the twin-engine F-22 Raptor and has inherited its technologies. The Mach 1.6 fighter has maximum take-off weight of 31,800 kg, which is significantly heavier than the fighters it will replace. The glass cockpit features 50 by 20 centimetres, full-panel-width “panoramic cockpit display”, a speech-recognition system and an advanced helmet-mounted display system (HMDS). For the first time, a frontline fighter has been designed without a headup display. The helmet gives an integrated fused “high off-bore sight” picture what some pilots call, ‘the God’s-eye view’. Fused information from on-/off-board avionics and sensors increases the pilot’s situational awareness, target identification and weapon delivery. Unlike in earlier aircraft, in the F-35, one does not need to physically point helmet or weapons towards the target. The highly advanced software makes it much easier to fly. A single press of the button could commence hands-off hover. Consultant to Lockheed Martin, Loren Thompson says that the “electronic edge F-35 enjoys over other tactical aircraft may prove to be more important in future missions than manoeuvrability”. The F-35 has an hands-on throttle and stick (HOTAS) concept with sidestick. The main sensor onboard is the Northrop Grumman APG-81, active electronically scanned array (AESA) radar augmented by the Lockheed Martin electro-optical targeting system. Six passive infrared sensors are distributed over the aircraft as part of Northrop Grumman’s AN/AAQ-37 aperture system which handles missile warning, detects and tracks threats approaching from any direction around the aircraft, and also replaces traditional night vision goggles. The AN/ASQ-239 is an improved version of the F-22 electronic warfare (EW) suite. It fuses radio frequency (RF) and infrared (IR) info for tracking, basic radar warning, electronic surveillance and multispectral countermeasures for self-defence against missiles. Communications, navigation and identification use the multifunction advanced data link, yet the non-stealthy Link 16 is retained to communicate with older systems.

The aircraft introduces lowmaintenance low-observable stealth technology through origami form, special coatings, hidden engine and low heat emission. Landing gear door has a stealthy saw-tooth design. The F-35 is not only radar stealthy, but also has infrared and visual signature reduction. The noise levels of the F-35 are known to be comparable to the F-22 and F-18 aircraft.

Structural composites constitute 35 per cent of the airframe, up from 25 per cent in the F-22. It will also be the first massproduced aircraft using nano composite materials. Its Pratt & Whitney F135 engine has demonstrated thrust of over 50,000 lbf during testing and is reportedly the most powerful engine ever installed on a single engine fighter aircraft. The logistics information and supply chain, as also computerised maintenance management, are meant to reduce downtime and man-hours.

Each variant has its own weapon mix. The F-35A includes a four-barrel 25mm internally mounted cannon. The F-35B & C have the same in external pod. There are two internal weapons bays, four external hard points under wing and two near wing tips. Multiple combinations of weapons can be carried. Typically in air-to-air role, eight AIM-120s and two AIM-9s and in airto- surface role, six 2,000 lb bombs with two AIM-120s and two AIM-9s can be carried. Solid-state lasers were being developed as optional weapons. The B-61 nuclear bomb is scheduled to be deployed by early 2020s. Max weapon payload is 8,100 kg.

The F-35A at 9g is the only variant on par with F-16 for manoeuverability. The carrier variant will be restricted to 7.5g which though comparable with the F-18, is lower than 9g for Dassault’s carrier based Rafale-M. Canard/thrust-vectored aircraft like the Eurofighter, Rafale F-22A, MiG-35 and the SU-35 will continue to enjoy some advantages which the F-35 hopes to neutralise using improved stealth, no drag from internally carried weapons and superior electronics.

The Block-3 F-35s were planned to have 8.6 million lines of software code. Yet there is need for additional software. Former US Air Chief General Norton Schwartz said that software is the biggest factor that might delay the initial operational clearance (IOC) which is rescheduled for April 2016. A maintenance man’s dream, the aircraft has 95 per cent of field-replaceable parts. The ejection seat can be replaced without removing the canopy. The stealth coatings are much easier to work with than those on the Raptor.

Important Milestones

The first F-35A flew on December 15, 2006. Pentagon thought advanced computer modelling and simulation would leave only minor problems to be discovered in flight testing. It was thus a conscious decision to run production concurrently with design and development. Important milestones included aerial refuelling in March 2008, supersonic flight on November 13, 2008, first flight of the F-35B on June 11, 2008, short take-off vertical landing (STOVL) propulsion system testing in flight in January 2010, the first hover on March 17, 2010, and the first vertical landing on March 18, 2010. On June 10, 2010, the F-35B became the second only to its ancestor X-35B STOVL aircraft to go supersonic. The Navy’s F-35C took to the air in June 2010. In October 2012, the first aerial weapon, an AIM-120 AMRAAM, was released. In September 2012, the USAF concurrently began operational utility evaluation (OUE) of the F-35A which included aircraft systems, logistical support and maintenance. It also paved the way for pilot training in January 2013. Test points achieved in 2012 exceeded the planned schedule and included deliveries of first two F-35s to the UK. In November 2012, the F-35 Lightning II programme crossed 5,000 flight hours.

Assembly and Work Share

Lockheed Martin provides the forward fuselage, wings, flight control system and the mission system. It carries out final assembly and overall system integration. Northrop Grumman provides the AESA radar, electro-optical distributed aperture system, communications navigation identification systems, centre fuselage, weapons bay and arrestor gear. BAE Systems provides aft fuselage and empennage, horizontal and vertical tails, lifesupport and escape systems, electronic warfare systems, fuel system and flight control software. Alenia will perform final assembly for Italy and for European customers with the exception of Turkey and the UK. Jon Schreiber, head of F-35 International Affairs Programme at the Pentagon, has said that the US would not share with allies the software code for the F-35.

The US plans to buy 2,443 F-35s. The remaining 600 are for the partners. Total development cost is estimated at over $40 billion ( Rs. 2,20,000 crore) and is largely underwritten by the US. The level of participation of other nations is linked to the funds contributed, quantum of technology transfer and the order in which countries have sought production aircraft. Level one partner, UK, invested $2.5 billion ( Rs. 13,750 crore); level two partners Italy invested $1 billion ( Rs. 5,500 crore) and Netherlands ($800 million or Rs. 4,400 crore); level three partners: Australia invested $144 million ( Rs. 792 crore), Canada ($160 million or Rs. 880 crore), Denmark ($110 million or Rs. 605 million), Norway ($122 million or Rs. 671 crore) and Turkey invested $195 million ( Rs. 1,072 crore). Security cooperation participants are Israel and Singapore. Japan intends to purchase 42 F-35s with deliveries beginning in 2016. Of these, at least 38 aircraft would be assembled in Japan. Fifteen per cent of each F-35 entering service over the next 25 years will be made in Britain by Rolls-Royce, BAE Systems, Martin-Baker and other smaller companies.

(To be continued)