Lockheed Martin has redesigned the bulkhead on the F-35B Joint Strike Fighter where the main landing gear meet the airframe to prevent the type of cracking that was found during ground stress tests on the jet, according to Lockheed and Marine Corps Commandant Gen. James Amos.
Amos revealed that the bulkhead has been "re-engineered" during a speech today at a Surface Navy Association conference in Arlington, Va. The four-star was discussing the future of the short take-off and vertical landing version of the JSF and the testing challenges it's been experiencing, saying that he believes Lockheed and the Pentagon can solve the jet's engineering difficulties in the next two years.
Lockheed officials confirmed the reworked bulkhead design, saying the flaw was only found on one plane used for ground tests and that the cracks, revealed last November, didn't contribute to the delays in the B's test schedule.
"After a thorough root-cause analysis, the F-35 program team has determined that the F-35B (BH-1 durability article) bulkhead cracks where the main landing gear attach to the airframe resulted from a large stress concentration," said company spokesman John Kent in an e-mail. "A redesign of the bulkhead is completed and an implementation plan has been developed. No cracking was found in any of the flight test aircraft, and flight testing has not been affected. Other locations of similar design are also being assessed."
Amos said the redesigned bulkhead was made of aluminum, not titanium. Some people had apparently worried that a titanium bulkhead would increase the plane's weight too much, according to the general.
Just last week Defense Secretary Robert Gates announced that he was putting the B-model on a two year probation, during which it will have to solve its development issues or be cut entirely from the JSF program.
When announcing the probation, Gates said the B-model "is experiencing significant testing problems. These issues may lead to a redesign of the aircraft's structure and propulsion, changes that could add yet more weight and more cost to an aircraft that has little capacity to absorb more of either."
Amos didn't say if the bulkhead was the structural redesign that Gates referred to last week.
Amos, the first fighter pilot to serve as commandant, added that he'll be closely watching and even micro-managing the B-program, albeit "in a legal way," over the next two years to make sure the jet isn't axed. He didn't elaborate on what he meant by, "a legal way."