A U.S. Air Force pilot waits in the cockpit of an F-35 Lightning II during a hot refuel on Eglin Air Force Base, Fla., Dec. 12, 2013. The F-35 Lightning II program is the Department of Defense's focal point for defining affordable next generation strike aircraft weapon systems for the Navy, Air Force, Marines and allies. (U.S. Air Force photo/Senior Airman Christopher Callaway)