Exercise Northern Lightning
Lt. Col. Todd Sheridan, 175th Fighter Squadron pilot, performs a walk around inspection during Exercise Northern Lightning at Volk Field Combat Readiness Training Center, Camp Douglas, Wisconsin, May 1-12, 2017. Northern Lightning is an exercise involving around 1,500 service members from the Air Force, Navy, Marines and National Guard across the country. (U.S. Air National Guard photo by Staff Sgt. Andrea F. Rhode/Released)