CF-01 and CF-02 in flight.

U.S. Navy test pilot Lt. Cmdr. Michael Burks, top, and Peter Kosogorin, a BAE Systems employee, bottom, fly F-35C Lightning II aircraft during a formation flying qualities test in the Atlantic Test Ranges over the Atlantic Ocean Sept. 5, 2012. The F-35C carrier variant of the Lightning II is distinct from the F-35A and F-35B variants with its larger wing surfaces and reinforced landing gear to withstand catapult launches and deck landing impacts associated with the aircraft carrier environment. The F-35C was undergoing test and evaluations prior to delivery to the fleet. (DoD photo by Layne Laughter, courtesy of Lockheed Martin/Released)