U.S. Air Force Senior Airman Chelsea Mays, 926th Aircraft Maintenance Squadron crew chief, applies lubrication to an F-15 Eagle during the Mission Employment Phase exercise, Dec. 7, 2012, at Nellis Air Force Base, Nev. The ME Phase is the capstone, graduation exercise conducted by the U.S. Air Force Weapons School. (U.S. Air Force photo/Senior Airman Brett Clashman)