U.S. Air Force Capt. Brad Matherne conducts preflight checks inside an F-35A Lightning II at Nellis Air Force Base, Nev., before a training mission on April 4, 2013. The F-35A will be integrated into advanced training programs such as the U.S. Air Force Weapons School, Red and Green Flag exercises. Matherne is a pilot assigned to the 422nd Test and Evaluation Squadron.