Successful high-speed testing of a Vision Systems International helmet-mounted display (HMD) has kept Lockheed Martin’s F-35 Joint Strike Fighter on track for a first flight in August 2006. Structural integrity problems with the optics had threatened to delay availability of the integrated HMD, which is required for flight because the JSF lacks a head-up display.

“There have been developmental challenges with the HMD, which is a very complex system that is essential for flight,” says Tom Burbage, Lockheed executive vice-president and general manager F-35 JSF programme integration. “It is just past the 600kt [1,110km/h] windblast test and is tracking the schedule, with some risk to first flight.”

Despite the test success, the HMD remains on a critical path to first flight. One option, says Burbage, is to begin flight testing without the full functionality of the helmet. Another is to use an HMD developed by BAE Systems for the Eurofighter Typhoon as a back-up, although he says this does not meet JSF requirements.

Lockheed, meanwhile, has mated the wing and fuselage sections of the first JSF, a conventional take-off and landing F-35A. The empennage is due to arrive from BAE during July, and power-on tests are planned for August 2005. The first aircraft, A-1, is the only one of the 15 flight-test aircraft not representative of the “weight-optimised” production JSF, but “will allow us to do system check-out and flying qualities,” testing, Burbage says.

A critical design review for the US Air Force F-35A and US Marine Corps short take-off and vertical landing (STOVL) F-35B is set for early next year, clearing the JSF for production beginning in 2007. The first F-35B will fly in 2007, with the first US Navy carrier variant (CV) F-35C to follow in 2009. This could be followed by the design of an adapted STOVL version for the USAF.

“We have told Air Combat Command that the soonest we can begin designing a USAF STOVL aircraft is after we have designed the CV, in 2009, for delivery in 2014-15,” says Burbage.


Source: Flight International