Airman 1st Class Kelby Baldwin, 28th Aircraft Maintenance Squadron crew chief, plugs a power cord into a B-1 bomber during a Phase II operational readiness exercise on the flightline at Ellsworth Air Force Base, S.D., July 10, 2013. Baldwin and other crew chiefs used an electrical generator to feed power into the aircraft's electrical systems while readying the aircraft for training during the exercise. (U.S. Air Force photo by Airman 1st Class Ashley J. Thum/Released)