Airman 1st Class Nathan Austin, 28th Operations Support Squadron aircrew flight equipment technician, removes an o-ring seal from a CRU-60/P hose from a pilot’s helmet on Ellsworth Air Force Base, S.D., Nov. 16, 2011. The o-ring seals must be cleaned often to ensure that dirt and bacteria are removed so pilots have clean and serviceable equipment. (U.S. Air Force photo by Airman Alystria Maurer/Released)