While the F-35 Lightning II joint strike fighter has returned to limited flying, it will not be appearing at the Farnborough International Airshow in the United Kingdom, Pentagon Press Secretary Navy Rear Adm. John Kirby said during a Pentagon news conference today.
The F-35 fleet was grounded July 3 in the wake of a June 23 engine fire on the runway at Eglin Air Force Base, Florida. Navy and Air Force airworthiness authorities approved the F-35's return to flight yesterday.
The return has a limited flight clearance that includes an engine inspection regimen and restricted flight rules, Kirby said, adding that the limits will remain in place until the root cause of the engine fire is identified and corrected.
While the investigation is not yet complete, "we haven't seen anything that points to a systemic issue across the fleet with respect to the engine," the admiral said.
Even with the return to flight, U.S. and British officials decided not to send Marine Corps and Royal Air Force F-35B aircraft across the Atlantic to participate in the Farnborough airshow. "This decision was reached after a consultation with senior leaders and airworthiness authorities, despite the decision by airworthiness authorities to clear the aircraft to return to limited flight," Kirby said.
"While we're disappointed that we're not going to be able to participate in the airshow," he added, "we remain fully committed to the program itself and look forward to future opportunities to showcase its capabilities to allies and to partners."
Under the rules of the flight resumption, the F-35s are limited to a maximum speed of Mach 0.9 and 18 degrees of angle of attack. They can go from minus 1 G to a 3 G's, the admiral said. After three hours of flight time, each front fan section of each engine has to be inspected with a borescope. "That was a pretty significant limitation in terms of being able to fly them across the Atlantic," he added.
This is not the first aircraft to have problems like this, Kirby noted, and it won't be the last. "New programs often go through these kinds of challenges," he said. "We're confident that we're going to get through this."