Aerospace propulsion technicians assigned to the 28th Aircraft Maintenance Squadron, prepare to inspect the propulsion system of a B-1 bomber parked on the flightline at Ellsworth Air Force Base, S.D., March 28, 2013. The B-1 bomber is equipped with four powerful turbofan engines that can produce more than 120,000 pounds of thrust. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)