Senior Airman Kymric Walker, 28th Maintenance Squadron aerospace propulsion technician, inspects the fan blades of a B-1 engine during a preposition spare engine inspection in the propulsion back shop at Ellsworth Air Force Base, S.D., Oct. 17, 2013. The Airmen of the propulsion back shop inspect more than 10 B-1 engines per month, ensuring they are mission ready and available when needed. (U.S. Air Force photo by Airman 1st Class Rebecca Imwalle/ Released)