Excessive' rubbing of engine blades caused F-35 failure

The engine failure that has grounded the entire fleet of F-35 fighter jets was caused by "excessive" rubbing of fan blades in the plane's Pratt & Whitney engine, but does not appear to be a fundamental design flaw, the Pentagon's chief weapons buyer said on Sunday.
Kendall said the grounding had halted testing but he did not view the incident as a "fundamental setback" for the program, which still has about 40 percent of developmental testing to complete.
The engine had suffered two issues involving fan blades in the past few years, but they appeared unrelated and not systemic to the airplane.
Detailed inspections of engines on the fleet of 97 F-35s already built had not shown signs of the kind of excessive rubbing founded on the engine that broke apart, although there were signs of milder rubbing in several other engines.
Kendall said the evidence being compiled did not point to a systemic issue, but the analysis was still going on. In this case, engineers found evidence of significant rubbing by the fan blades against a cowl.
reuters