Engineers have discovered the flaw that has grounded the Marine Corps' version of the F-35 since Jan. 18, Pentagon and industry officials have said.
Pentagon officials said the problem is with an "improperly crimped" fluid line, according to a Bloomberg report. Marine leaders said the problem is not caused by any "further design or maintenance issues,' the report said.
Marine officials grounded their F-35 B fleet after a pilot aborted a takeoff at Eglin Air Force Base, Fla., because of problems with the propulsion system. Pratt & Whitney build the propulsion system under the aircraft program that is overseen by Lockheed Martin.
The fluid line is found in the plane's fueldraulic system where the aircraft uses jet fuel rather than hydraulic fluid to lubricate mechanical parts, Bloomberg's report said.
The F-35 program remains tenuous as test flights continue. Lockheed Martin and the Defense Department officials have recently reported progress toward making up for delays and spiraling budgets seen over the past decade for the U.S. military's most expensive weapons program.
Pratt & Whitney engineers have begun removing the "suspect" parts and continue to X-ray the aircraft for other problems with the propulsion system, said a Pratt & Whitney spokesman in a statement.
“The team continues to work diligently toward completing the investigation and implementing corrective actions with the supplier,” Bates said in a statement. “We anticipate a return to flight” soon.