The Lockheed Martin F-35B short take-off and vertical landing (STOVL) variant of the Joint Strike Fighter has returned to flight after a 25-day grounding.
"F-35B flight clearance was restored February 12, rescinding a cautionary suspension issued January 18 after a fueldraulic hose failure," the F-35 Joint Program Office (JPO) says. "Government and industry engineering teams conducted a root cause investigation and determined the hose was improperly crimped."
The fueldraulic hose powers the actuator movement for the F-35B's STOVL thrust vectoring exhaust system.
Hoses on all 25 F-35B aircraft currently in the US Marine Corps and UK inventory have been inspected. Those aircraft found to have defective parts will have improperly crimped hoses replaced, the JPO says. It had said earlier that the investigating team found a total of seven aircraft had the manufacturing defect.
The F-35B fleet, which is located at NAS Patuxent River, Maryland, Eglin AFB, Florida, and MCAS Yuma, Arizona, has been cleared to fly once the re-installation of "compliant" hoses is complete, the JPO says.
Flight operations for the conventional take-off and landing F-35A and F-35C carrier variant aircraft were unaffected by the grounding.