The F-35 Lightning II Joint Strike Fighter (JSF) programme office has resolved the aircraft’s wing structure problem.

During US Department of Defense (DoD) testing, the root rib developed cracks after just 2,800 hours, compared with a required life of 8,000 flight hours.

JSF programme spokesman Joe Dellavedova said the crack was consistent with analytical predictions, both in terms of location and life.

“Resolving durability test article findings is a well-understood process. Durability testing is conducted early in the development of any new aircraft to avoid costly sustainment issues later in the life of the aircraft.

“Problems are found and corrected in development rather than fleet service,” Dellavedova added.

The JSF programme will incorporate new modified forward root rib design in to 30 conventional take-off and landing (CTOL) and 34 short take-off and vertical landing (STOVL) aircraft.

The forward root rib modification is expected to take about 45 days to complete, according to DefenseNews.