All versions — a total of 51 planes — were grounded Friday pending a more in-depth evaluation of the problem discovered at Edwards. None of the planes have been fielded for combat operations; all are undergoing testing.
In a brief written statement, the Pentagon said it is too early to know the full impact of the newly discovered problem.
A watchdog group, the Project on Government Oversight, said the grounding is not likely to mean a significant delay in the effort to field the stealthy aircraft.
"The F-35 is a huge problem because of its growing, already unaffordable, cost and its gigantically disappointing performance," the group's Winslow Wheeler said. "That performance would be unacceptable even if the aircraft met its far-too-modest requirements, but it is not."
Built by Lockheed Martin in Fort Worth, Texas, the F-35 is the Pentagon's most expensive weapons program at a total estimated cost of nearly $400 billion. The Pentagon envisions buying more than 2,400 F-35s, but some members of Congress are balking at the price tag.
Friday's suspension of flight operations will remain in effect until an investigation of the problem's root cause is determined.
The Pentagon said the engine in which the problem was discovered is being shipped to a Pratt & Whitney facility in Connecticut for more thorough evaluation.
More Nation & World Headlines
Four Confederate flags left at MLK center, church in Atlanta 7:48 a.m. Cincy police officer pleads not guilty in fatal shooting 7:47 a.m. Cop indicted for murder in traffic-stop shooting Will ‘Happy Birthday’ song be free to use soon? Debris linked to missing Malaysian 777 Export-Import Bank excluded from highway bill 777 departs Aleutians after emergency landing House approves highway funding bill
Our new comment system is not supported in IE 7. Please upgrade your browser here.