By Andrea Shalal
WASHINGTON, July 7 (Reuters) - Most of the 97 Lockheed Martin Corp F-35 fighter jets grounded last week have been inspected, and officials hope to wrap up the remaining inspections on Monday, which could pave the way for the resumption of flights of the Pentagon's newest warplane, U.S. military officials said.
Senior officials with the U.S. Navy, Air Force and F-35 program office, as well as from Britain and the Netherlands, will review the results of inspections of the jets' Pratt & Whitney engines to determine whether and under what circumstances to resume flights.
The U.S. military last week ordered a fleetwide grounding of the F-35 Joint Strike Fighter after the engine on an Air Force F-35 A-model jet broke apart and caught fire as a pilot was preparing to take off from Eglin Air Force Base in Florida.
The incident threatens what was to be the F-35's international debut at two air shows in Britain that kick off on Friday and next week. No decision has yet been made on whether to allow F-35 jets to fly to Britain, an official with the Pentagon's F-35 program office said.
Officials investigating the fire have determined what happened to the F135 engine built by Pratt, a unit of United Technologies Corp, but are still trying to understand why it happened, said one source familiar with the program.
Four Marine Corps F-35B jets are parked at an air base in southern Maryland, ready to travel to Britain. A fifth jet, a British F-35B, remains at Eglin.
If officials allow flights to resume, the British jet could fly to Maryland on Tuesday, and the group of F-35Bs could depart for England on Wednesday, according to two sources.
The aircraft must leave by Wednesday to be ready for flights at the Royal International Air Tattoo on Friday. But the jets could still make it to Britain for the big Farnborough show next week, officials said.
The incident has put on hold U.S. contract negotiations for the next batches of fighter jets and engines, which officials had hoped to conclude before the air shows, according to the Pentagon's F-35 program office and industry officials.
"There is some hesitation to conclude the contract negotiations until the scope of the issue is fully understood," said an official with the program office.
Lockheed's previous contracts with the Pentagon call for a 50-50 split of costs with the government, but the government is still trying to hammer out a similar arrangement with Pratt.
(Reporting by Andrea Shalal; Editing by Ros Krasny and Mohammad Zargham)