Propulsion Shop
Staff Sgt. Luke Keigley, 28th Maintenance Squadron aerospace propulsion journeyman, secures and tightens an anti-ice valve on a B-1B engine at Ellsworth Air Force Base, S.D., Jan. 18, 2012. This protects the engine from damage by flowing bleed air to the inlet guide veins which melts potential ice build up, preventing damage to the fan blades. (U.S. Air Force photo by Airman Alystria Maurer/Released)