WASHINGTON, June 26 (Reuters) - The U.S. Air Force widened a ban on flights of Lockheed Martin Corp's F-35 A-model fighter jets on Thursday as authorities continue to investigate a fire on one of the jets this week, but the Navy and Marine Corps stopped short of a similar blanket move ahead of the plane's international debut next month.
"As a precautionary measure, the Air Force has decided to temporarily suspend all F-35A operations until it is determined that flights can resume safely," Air Force spokeswoman Major Natasha Waggoner said in a statement.
She said the Air Force decision would ensure the safety of its crews and aircraft while authorities determine if there was a fleet-wide issue that needs to be addressed.
Monday's fire was initially described as a "one-off" incident, but concerns have grown given the dearth of information from an Air Force-led probe into the "significant fire" that broke out in the rear of an F-35A jet and forced its pilot to abort a takeoff on Monday morning.
The incident came days before Marine Corps B-model jets were due to fly to Britain for the jet's closely watched international premiere, and as Canada neared a decision on how to replace its aging fleet of Boeing Co F/A-18 fighter planes.
It followed mandatory inspections of all 97 F-35 jets ordered earlier this month after an F-35B suffered an oil leak in flight. All but three jets resumed flights within days of that incident.
Defense officials said some details from an initial assessment of the fire could emerge later on Thursday.
Analyst Richard Aboulafia with the Teal Group said the incident would have little impact if it was resolved quickly. "But if it persists, and if some kind of system redesign work is needed, that could impact budget and program plans," he said.
U.S. Navy spokeswoman Lieutenant Jackie Pau said local commanders had suspended flights of some B- and C-model F-35 jets, but officials were waiting for initial assessments from investigators before deciding whether to halt all flights.
The Marine Corps had planned to ferry B-model jets to an air base in southern Maryland this week to prepare for their flights to Britain, which is one of the key partners that helped fund development of the new multinational warplane.
The F-35 is due to appear at two air shows in Britain next month and make a brief appearance at the naming ceremony for Britain's new aircraft carrier on July 4, weather permitting.
Marine Corps spokesman Captain Richard Ulsh said F-35B flights would resume once more data was available about the cause of the fire. He said there were no changes at the moment to the Marine Corps' plans to send planes to Britain.
F-35 program spokeswoman Kyra Hawn said the flight suspensions fell short of a formal grounding order. "As more information becomes available, airworthiness authorities at the services will determine what steps to take." (Editing by Matthew Lewis)