The U.S. military has announced it is grounding its fleet of F-35 warplanes after a crack was found in the engine of one of the planes at a military base in California.
The Defense Department said it was working with the manufacturer of the engine -- Pratt and Whitney -- and the aircraft, Lockheed Martin, to clear up the problem.
It is the second time in the last two months that the military has grounded the fleet.
The fighter jet has been plagued by cost overruns and other problems.
The military has 51 F-35s, which are used by the Navy, Air Force, and the Marines.
Based on reporting by dpa and AP