A U.S. Air Force crew chief assigned to the 58th Aircraft Maintenance Squadron, Eglin Air Force Base, Fla., salutes the F-35 Lightning II pilot as he prepares for takeoff at Joint Base Langley-Eustis, Va., April 20, 2017. With its aerodynamic performance and advanced integrated avionics, the F-35 Lightning II provides next-generation stealth, enhanced situational awareness and reduced vulnerability for the United States and allied nations. (U.S. Air Force Photo/Airman 1st Class Tristan Biese)