U.S. Air Force Tech. Sgt. Richard Hennes, a 148th Fighter Wing aircrew flight equipment craftsman from Duluth, Minn., performs a pre-flight inspection on a pilot's helmet, Aug. 10, 2015, while participating in RED FLAG-Alaska 15-3 at Eielson Air Force Base, Alaska. RF-A is a Pacific Air Forces commander-directed field training exercise for U.S. and partner nation forces, providing combined offensive counter-air, interdiction, close air support and large force employment training in a simulated combat environment. (U.S. Air Force photo by Master Sgt. Ralph Kapustka/Released)