Staff Sgt. William Haller, 28th Operations Support Squadron aircrew flight equipment technician, straps on headgear for Capt. Christopher Ross, 34th Bomb Squadron B-1 pilot, during aircrew chemical defense ensemble training at Ellsworth Air Force Base, S.D., May 29, 2014. The headgear is designed to filter contaminated air, allowing wearers to continue their tasks. (U.S. Air Force photo by Senior Airman Anania Tekurio/Released)