Lockheed Martin JSF X-35 News

Lockheed Martin X-35C breaks sound barrier

2 February 2001
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The Joint Strike Fighter (JSF) X-35C carrier variant (CV) began a series of supersonic envelope-expansion flights on 31 January, becoming the second Lockheed Martin JSF demonstrator to exceed the speed of sound.

In two separate flights, test pilot Joe Sweeney climbed to 25,000 feet and accelerated to Mach 1.05, then to Mach 1.10, testing the Navy JSF's supersonic performance. The flights are the first in a series designed to test the X-35C at increasingly higher supersonic speeds, and they are among the last before the plane's scheduled transcontinental flight to the US Navy flight-test centre at Patuxent River, Md.

"Pushing the envelope past Mach 1 in an aircraft that is essentially identical to our proposed production JSF enables us to know today how that production plane of the future will handle at supersonic speeds,'' said Tom Burbage, executive vice president and general manager of the Lockheed Martin JSF program. "It's a very important exercise in risk reduction, and reducing technical risk is the cornerstone of our flight-test program.''

The X-35A broke the sound barrier on Nov. 21, 2000, opening up the JSF supersonic envelope for the US Air Force and US Marine Corps. Each aircraft is powered by a single Pratt & Whitney JSF119-611 engine, developing about 40,000 pounds of thrust.

On 25 January, the X-35C completed tanker qualification trials with a series of air-to-air refuellings behind a US Air Force KC-10. Naval probe-and-drogue refuelling demonstrations are scheduled during the aircraft's testing period at Patuxent River.

The X-35C, designed to satisfy US Navy requirements, features a larger wing and control surfaces than the other JSF variants, and has an increased- capacity structure for absorbing catapult launches and arrested landings.

The X-35A conventional-takeoff-and-landing (CTOL) variant, built to US Air Force specifications, completed its flight-test programme in November last year.

The X-35B short-takeoff-vertical-landing (STOVL) demonstrator is expected to begin hover-pit testing this month. Designed to meet US Marine Corps and British Royal Air Force/Royal Navy requirements, the X-35B features a shaft-driven lift fan that amplifies engine thrust and reduces exhaust temperature and velocity during STOVL operations.

The single-seat, single-engine JSF will be a stealthy and highly sophisticated replacement for an ageing fleet of US and British warplanes, including the A-10, F-16, F/A-18 and Harrier.

Lockheed Martin, in partnership with Northrop Grumman and BAE SYSTEMS, is competing with Boeing for the JSF contract for the United States and United Kingdom. Government selection of a single contractor for the Engineering and Manufacturing Development phase is set for fall 2001.


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JSF X-35B begins final phase of flight test

6 June 2001

The short-takeoff/vertical landing (STOVL) version of the Lockheed Martin Joint Strike Fighter, the X-35B, has begun ground runs as the countdown begins to the aircraft's final phase of STOVL flight.

The plane completed its conventional and STOVL wing-borne flight requirements last autumn and will begin STOVL takeoff and landing operations, beginning with vertical takeoffs, in late June or early July.




The Lockheed Martin JSF team completed installation of the JSF X-35B's flight-ready propulsion system, including the shaft-driven lift fan and engine, on 12 May. Pilot Simon Hargreaves began operating the flight-ready system in the aircraft on 24 May.
Additionally, the government JSF Programme Office completed a first-flight readiness review of the X-35B on 22-23 May in preparation for the beginning of STOVL flight testing. Engineering groups from the JSF Programme Office, an independent review team and a Joint United States Air Force/US Navy/US Marine Corps Safety Review Board met with the Lockheed Martin-led X-35 team to review engineering and test results of all X-35B STOVL development work, as well as plans for the STOVL flight-test programme.

Flight test will begin with a series of vertical takeoffs at the Lockheed Martin plant in Palmdale, Calif. Follow-on flights will include transitions to and from conventional and STOVL modes. Hargreaves, a veteran Harrier pilot from BAE SYSTEMS, will be the X-35B's principal contractor test pilot.

The X-35B, designed to meet US Marine Corps and Royal Navy/Royal Air Force requirements, features a unique propulsion system in which a drive shaft from the engine turns a counterrotating lift fan that produces tremendous cool-air lifting force during STOVL operations. The front-mounted fan works in concert with a thrust-vectoring rear engine nozzle and under-wing lateral-control nozzles to produce nearly 40,000 pounds of lifting power. Rolls-Royce produces the fan and nozzles. The Pratt & Whitney engine is based on the F-22 power plant.


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First US Marine Corps pilot flies JSF X-35B

2 July 2001

The US Marine Corps has had its first pilot evaluation of the Lockheed Martin Joint Strike Fighter's vertical takeoff, hover and vertical landing performance. Major Art ''Turbo'' Tomassetti became the first Marine and only the second pilot to fly the short-takeoff/vertical landing (STOVL) X-35B, which is demonstrating JSF requirements for the Marines and the United Kingdom Royal Air Force/Royal Navy. With this flight, Tomassetti also becomes the first pilot to have flown all three X-35 variants: the X-35A, X-35B and X-35C.

''On a hot day in the high desert, the X-35B demonstrated the kind of vertical performance that Harrier pilots dream about,'' said Tomassetti, a Harrier pilot who also serves as X-35 test pilot for the Marine Corps. ''With my three press-ups today I am convinced that we are on the right track. ''

''As we saw today, the X-35B continues to demonstrate phenomenal lifting power in unfavourable conditions: 2,500-foot high-desert elevation with temperatures above 80 degrees Fahrenheit. And the airplane is incredibly stable,'' said Tom Burbage, executive vice president and general manager of the Lockheed Martin JSF programme.

The X-35B made its first vertical takeoff and vertical landing on 23 June and since then has hovered numerous times at up to50 feet above the ground. A Royal Air Force pilot is scheduled to fly the aircraft over the weekend. Upcoming milestones include a flight to Edwards Air Force Base, California, where the plane will transition from conventional flight to hover, and will execute short takeoffs and vertical landings. As configured, the aircraft is ready for supersonic flight.


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Royal Air Force pilot goes vertical

3 July 2001

Squadron Leader Justin Paines has become the first Royal Air Force pilot to evaluate the vertical takeoff, hover and vertical landing performance of the supersonic Lockheed Martin Joint Strike Fighter X-35B.

Paines, a Harrier pilot who was selected to test the X-35 demonstrator aircraft for the United Kingdom, roared into the air with a series of three hovers for a total of eight and a half minutes at the Lockheed Martin plant in Palmdale, Calif., on June 30.

"It was awesome. The aircraft performed flawlessly,'' Paines said. "The system produces an incredible amount of thrust, 15 or 20 tons of thrust, even here in the high desert in summer, and yet we can control that thrust with the precision required to manoeuvre the aircraft in the hover.

"Apart from having to adhere to the upcoming flight-test phase, there was nothing that would have stopped me accelerating away to supersonic speed with the same aircraft.''

BAE SYSTEMS, along with US defense contractor Northrop Grumman, is a major partner on the Lockheed Martin JSF program.

The X-35B is designed to fulfil performance requirements for the Royal Air Force, Royal Navy and US Marines. It made its first vertical takeoff and vertical landing on 23 June. Since then it has hovered numerous times at up to 50 feet above the ground, and will begin transitions from conventional flight to hover in the coming weeks.

The X-35B features a unique propulsion system in which a drive shaft from the Pratt & Whitney JSF119-611 engine turns a counter-rotating lift fan that produces cool-air lifting force during STOVL operations. The Rolls-Royce fan, actuated by a clutch that can be engaged at any power setting, works in concert with an articulating rear duct and under-wing lateral-control nozzles to lift the aircraft with nearly 40,000 pounds of vertical force. Because the fan amplifies the engine's power, the engine is able to run cooler and with less strain, increasing reliability and extending service life. The lift fan provides the propulsion system with about 10,000 pounds more thrust than the engine alone could generate.

The Lockheed Martin team approach to the STOVL flight-test programme is based on fielding and flying a demonstrator that solves the marginal thrust levels associated with direct-lift STOVL aircraft, so that both technical risk and cost are reduced before the JSF's production phase.

Lockheed Martin is in competition with Boeing to build the JSF for the United States and United Kingdom. Government selection of a single contractor for the Engineering and Manufacturing Development phase is set for fall 2001.


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