Responding to reports that routine inspection conducted on a Lockheed Martin (NYSE:LMT) F-35 Lightning II discovered a crack in one of its engine blades, the Department of Defense ordered all F-35s grounded Friday. The Pentagon called the move a "cautionary suspension."

The plane initially discovered to contain the fault was an F-35A model of the plane flown by the Air Force. The F-35 engine at fault has been removed from the plane and will be shipped to Pratt & Whitney, a subsidiary of United Technologies (NYSE:UTX) and manufacturer of the engine, for examination.

In a statement, the Pentagon said: "The F-35 Joint Program Office is working closely with Pratt & Whitney and Lockheed Martin at all F-35 locations to ensure the integrity of the engine, and to return the fleet safely to flight as soon as possible."