Senior Airman Andrew Knill, 28th Maintenance Squadron hydraulics specialist, safety-wires a bolt on a B-1B integrated servo actuator during a maintenance inspection at Ellsworth Air Force Base, S.D., Feb. 2, 2012. The servo actuator controls the horizontal stabilizers that allow the B-1B to perform tactical maneuvers. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)