Tech Sgt. Joseph LeFors, 28th Maintenance Squadron test cell section chief (left) and Staff Sgt. Joshua Dean, 28th MXS assistant test cell section chief, perform a B-1 bomber engine test run at the engine test cell at Ellsworth Air Force Base, S.D., Sept. 12, 2014. The six-step engine flow testing process includes an inspection to determine work scope, maintenance, and a performance run. (U.S. Air Force photo by Airman 1st Class Rebecca Imwalle/ Released)