U.S. Navy maintains grounding order for F-35 fighter jets
(Reuters) - The U.S. Navy maintained a grounding order for F-35 B-model and C-model fighter jets built by Lockheed Martin Corp (LMT.N), saying it was still not clear what caused a massive engine failure on an Air Force F-35 jet last month. The fleetwide grounding order kept three Marine Corps F-35 B-model jets and one British F-35B from traveling to Britain for widely publicized appearances at two air shows.
"At this time, I do not have sufficient information to return the F-35B and F-35C fleet to flight," Vice Admiral David Dunaway, who heads the Navy's Air Systems Command, said in an update to a grounding order issued by U.S. officials on July 3. A copy of the document was obtained by Reuters. In the document, Dunaway said he was committed to returning the F-35 fleet to flight as soon as possible, but there was still "no discernible event that represents a root cause."
The memo emerged after a lengthy meeting on Friday of the officials responsible for determining the "airworthiness" of the F-35, according to sources familiar with the matter........
Marine Lieutenant General Jon Davis, deputy commandant for aviation, told Reuters late on Friday that the jets might not appear at the Farnborough air show, which begins next week......."Until the grounding is lifted, the U.S. Marine Corps and Britain will not be able to ferry the F-35B aircraft to Britain for the jet's planned international debut at two air shows there this month - the Royal International Air Tattoo, the world's largest military air show that began on Friday, and the Farnborough air show, which starts on Monday and runs until July 20".....
Dunaway said the Navy and other services are continuing to investigate the incident, and planned to update the flight directive no later than July 16 - two days after the start of the Farnborough air show outside London.......
Dunaway's memorandum did not rule out the possibility that the most advanced U.S. fighter jet could still appear toward the end of the Farnborough air show, but the prospects of that occurring appeared to be dimming fast. "There are specific additional evaluation conditions required to support the Farnborough air show in the UK, including the ferry flight across the Atlantic and performance in the air show itself. Additional work is required in order to understand and mitigate air show unique risks," it said......
Dunaway said the current analysis would have to be refocused to allow the F-35's participation in the Farnborough air show. The jets need a full day in Britain to allow for any maintenance or repairs before they participate in flying demonstrations. Dunaway said officials were looking at possible operational restrictions for the jets while the issue was being investigated, and would also likely implement repeated engine inspections to monitor for any indication of a future problem. But those measures would take several more days to complete.
It remains unclear what caused the third stage of the Pratt engine to break apart. The incident severed a fuel line, which then caused a fire.
Frank Kendall, the Pentagon's chief weapons buyer, told U.S. lawmakers on Thursday there was "growing evidence" that the incident was an individual event and had not been caused by a systemic issue. He said all existing engines had been inspected and that no similar issues had been found, but he said safety was the Defense Department's top priority.