Defense Media Network

F-35B Lightning IIs Miss Farnborough Airshow, Remain Within Restricted Flight Envelope

Rear Adm. John Kirby confirmed in a Department of Defense briefing that the four F-35B Lightning IIs scheduled to fly to England to attend the Farnborough International Airshow will remain on the ground.

“I can confirm that the Department of Defense in concert with our partners in the U.K. has decided not to send Marine Corps and U.K. F-35B aircraft across the Atlantic to participate in the Farnborough air show,” Kirby said in a statement to reporters. “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 flight – to limited flight.

Kirby did detail the flight envelope restrictions, and said that “…right now, the aircraft are limited to a max speed of 0.9 Mach, 18 degrees of angle of attack. They can go from -1 to +3Gs and a half a stick deflection for rolls.”

“When we operate aircraft, we look at many factors, to include operational risks, the weather, ground time, maintenance issues. All of these factors were weighed appropriately in making this difficult decision. And while we’re disappointed that we’re not going to be able to participate in the air show, we remain fully committed to the program itself and look forward to future opportunities to showcase its capabilities to allies and to partners.

“As Secretary Hagel has made clear, safety as always remains our top priority. And we’ll continue to provide you up-to-date information as we can and as it becomes available.”

No mention was made during the briefing of test pilot Alan Norman’s comment that the fire may have been caused by third stage blades rubbing against a stationary part of the engine.

100th F-35

The 100th F-35 Lightning II produced in Fort Worth, Texas, an F-35A, takes off for the first time on Dec. 15, 2013. An F-35A variant experienced the runway engine fire in June that grounded the fleet, now returning to restricted flight. Lockheed Martin photo

Kirby did detail the flight envelope restrictions, and said that “…right now, the aircraft are limited to a max speed of 0.9 Mach, 18 degrees of angle of attack. They can go from -1 to +3Gs and a half a stick deflection for rolls.

“More critically, after three hours of flight time, each front fan section of the – of each engine has to be inspected with a borescope. So after every three hours of flight time, you’ve got to do a borescope inspection of the front fan section of the engine. That was a pretty significant limitation in terms of being able to fly them across the Atlantic.

“Not the first aircraft to have problems like this. It’s not going to be the last. New programs often go through these kinds of challenges. We’re confident that we’re going to get through this.”

Kirby emphasized the Pentagon’s continued commitment to the program, and his belief that based on available evidence, the fire was not an indication of a systemic problem across the fleet.

“We’re actually glad for the news today to be able to get the aircraft back in the air, even if it is limited,” he said. “We fully expect to work our way through this problem and restore the full operational capability in the near future.

“This by no means should signal any lack of commitment to the F-35 or to its future in the U.S. military or in those militaries of partner nations that want to purchase it. It’s the next-generation fighter aircraft, and we remain committed to that.

“Not the first aircraft to have problems like this. It’s not going to be the last. New programs often go through these kinds of challenges. We’re confident that we’re going to get through this,” Kirby said.

“And I would also add that, you know, after all the inspections and the work – now, I want to caveat this, because the investigation is not complete yet – …we haven’t seen anything that points to a systemic issue across the fleet with respect to the engine. Again, that can change. I want to caveat that right off the bat, but the point is that leadership feels increasingly comfortable and confident in working the aircraft back to flight.”