Boom! Army Staff Sgt. David Riley, foreground, covers his ears while observing M136E1 AT4-CS light anti-armor rocket launcher live-fire training at Joint Base Elmendorf-Richardson, Alaska, Oct. 12, 2017. Riley is assigned to the 109th Transportation Company, 17th Combat Sustainment Support Battalion. Air Force photo by Alejandro Pena SHARE: Download: Full Size (2.31 MB) Tags: Northcom, Northern Command, Soldiers, Army, training Credit: Alejandro Pena VIRIN: 171012-F-YH552-0034A.JPG Photo Gallery