Pentagon orders all F-35 jets grounded

Lockheed Martin,which makes the plane,said 64 of the jets would be affected. The Pentagon estimates that it could spend as much as 396 billion to buy 2,456 of the jets by the late 2030s. But the programme,the most expensive in military history,has been plagued by cost overruns and delays.

The Marines also had to suspend operation of their version from January 18 through February 13 because of a problem with a crimped hose in the fuel system.

The Pentagon office that runs the programme said the crack in the turbine blade was discovered on Tuesday in a routine inspection. The crack occurred on a test plane at Edwards Air Force Base in California. The blade is being shipped to a plant in Connecticut,where the engine manufacturer,Pratt amp; Whitney,will inspect it and look for the problems cause.