HILL AIR FORCE BASE — F-35s were grounded for the second time in their three-year history at Hill Air Force Base last week, but officials say the action was purely cautionary and all jets have already returned to the skies.
In an email, 388th Fighter Wing spokesman Micah Garbarino said the Air Force ordered a “temporary pause in flight operations” for all F-35A Lightning II aircraft on Oct. 11. Garbarino said the halt in flight activity was done as a precaution and to allow all aircraft to go through a mandatory inspection that was requested by the F-35s Joint Program Office at the Pentagon.
According to a statement from the JPO, all U.S. Services and international partners temporarily suspended F-35 flights while the enterprise conducted a fleet-wide inspection of fuel tubes inside the engines of all active aircraft.
The JPO statement said the inspections were driven by initial data from the ongoing investigation of the F-35B that crashed in South Carolina on Sept. 28. A Department of Defense aircraft mishap board is still working on the investigation and the U.S. Marine Corps will provide more information when it becomes available.
“The primary goal following any mishap is the prevention of future incidents,” the JPO statement says. “We will take every measure to ensure safe operations.”
As part of the inspection process, F-35s maintenance crews removed and replaced faulty fuel tubes. Garbarino said maintainers at the 388th FW completed their inspections the same day flights were suspended and resumed flying operations later that afternoon.
Last week’s grounding was the second time Hill F-35 flights have been suspended as a result of a fuel related problem.
In late 2016, the Air Force grounded 13 operational F-35As (including 10 jets at Hill) after crews on base discovered peeling and crumbling of the avionic cooling line insulation inside one of the F-35’s fuel tanks. A total of 57 F-35s were impacted by the 2016 problem. Hill’s jets went back into the air a little more than a month after the issue was first detected.
Hill’s Ogden Air Logistics Complex performs maintenance on all Air Force F-35s. The base’s two fighter wings fly the agency’s first operational fleet of the fighter jets. The first two arrived in late 2015 and Hill will continue to receive regular shipments of the jet until 2019, when 78 planes will fill three operational fighter squadrons.