Spc. Matthew Hammond, an aviation mechanic in the California Army National Guard’s Detachment 1, Company F, 2nd Battalion, 135th General Support Aviation Battalion, performs flight-line maintenance on an UH-60 Black Hawk helicopter at Mather Air Field, Calif., Sept. 6. This UH-60 Black Hawk is one of two rotating weekly on stand-by for any medical evacuations from the Rim Fire. (U.S. Army National Guard photo/Spc. Nadine White/Released)