PETERSON AIR FORCE BASE, Colo. – Donald Mitchell, a fuels distribution system operator with Defense Logistics Agency, refills a fuel truck at Peterson Air Force Base, Colo., Sept. 19, 2016. The dual-safety features include an automatic shut-off when the fuel reaches the top of the tank, and also a kill-switch that shuts off the pump if anything were to happen to the operator and they release their grip on the switch. (U.S. Air Force photo by Philip Carter)