F-35 Grounded

The U.S. Navy has grounded the Marine Corps' F-35B variant on Friday after an exhaust system failure.  A and C-model variants were said not to be affected.


The incident came just days after the Pentagon's director of testing and evaluation released an 18-page report detailing an array of problems which he said underscored the "lack of maturity" of the $396 billion fighter program.

The report and Friday's grounding of the B-model highlighted the continued growing pains of the ambitious Lockheed fighter program, which began in 2001 and has been restructured three times in recent years.