The Pentagon does not have a timeline for when the F-35 will fly again after military leaders grounded the fleet on Feb. 22, said George Little, the head Pentagon spokesman.
He explained that engineers and investigators continue to inspect the F-35's engine after a defect was found in one of the engine blades.
"What we're doing right now is the prudent and logical thing, and that is to see if this is a limited defect in one plane on one engine or if this is a design error or flaw that may affect other aircraft in the fleet," Little said. "That's what we're examining right now, and we remain fully committed to fixing this problem and to the F-35 program."
The Pentagon grounded all three versions of the plane as the program continues to work to continue to make up for lost time. The grounding is sure to set the program back in its testing regimen.
The defect was crack found in a turbine blade of one of the aircraft. The grounding will leave 64 aircraft that could be flown for test flights on the ground.
Pratt & Whitney builds the engines for the aircraft. Lockheed Martin is primary company on the military's most expensive program in military history.
The plane with the cracked turbine blade was shipped to Connecticut where Pratt & Whitney engineers with inspect it. The aircraft had been stationed at Edwards Air Force Base, Calif.
"We're committed to addressing this problem as quickly as possible, and once we have something to report, I will," Little said.