F-35C flying briefly suspended over software problem


The carrier-based F-35C variant of Lockheed Martin’s Joint Strike fighter was suspended from flying between June 17 and 23 over a software problem that could have caused flight control surface malfunctions.

The US Navy’s F-35C variant was grounded on June 17 after engineers at Patuxent River Naval Air Station in Maryland discovered a “logic fault” with software, that could have affected the flight control surfaces.

According to Navy spokesperson said Lieutenant Courtney Hillson, the problem affected a “safety mechanism that ensures the wings are folded properly. It’s the mechanism that prevents the flaps from folding in flight.”

The safety monitoring function for the folding mechanism should be turned off during flight, Hillson said, but the software was not properly turning off the function. However, the Navy pointed out that no faults actually occurred.
“A software fix is in progress, and the team has structured temporary manoeuvring limitations to ensure it is not a safety hazard,” Naval Air Systems Command (NAVAIR) at Patuxent River said in a statement. Nevertheless, aircraft have resumed flying under certain restrictions.
“Finding issues such as this is the purpose of aircraft test and evaluation,” Hillson said. “By finding and correcting such issues, the test team is delivering a better product to the fleet.”

Three Navy F-35Cs have been undergoing flight testing at Patuxent River since November last year. Despite the software glitch, the Navy “is still on track to commence initial carrier suitability testing next week with jet blast deflector testing in Lakehurst, NJ,” NAVAIR said in a statement on Friday. In late July or early August the F-35C will undergo catapult launch and arrested recovery tests, Hillson said.

The F-35 is being developed in three variants for the US Marine Corps, US Air Force and US Navy, as well as eight allies. The programme, restructured twice in two years, has exceeded cost expectations and is currently expected to cost US$382 billion.

Problems with the programme, including delays, an alternative engine and technical issues, were meant to be assessed during a high-level Pentagon review this month. However, on June 15 the Defence Department announced that the review has been delayed until later in the year to allow time to gain more test and production data.

Pentagon spokeswoman Cheryl Irwin said the meeting of the Defence Acquisition Board, which includes senior defence officials including Defence Undersecretary Ashton Carter, had been deferred a few months to incorporate information from the fiscal year 2013 budget process and to include the latest updates to the program’s schedule.

The meeting of the panel would likely be rescheduled sometime in October, said a senior defence official who was not authorized to speak on the record.

At the meeting, the panel is due to establish a new procurement baseline for the F-35.

Two weeks ago Lockheed said the F-35 fighter had conducted 411 test flights this year. The defence contractor said the F-35 programme was running ahead of test-flight goals year-to-date, adding that through May 31, the program had made 378 flights versus 297 planned.