U.S. Air Force Airman 1st Class Michael Abreu powers on a generator to test an air conditioning unit on a C-130 Hercules aircraft on Bagram Airfield, Afghanistan, Nov. 11, 2015. Abreu is an electrical and environmental systems technician assigned to the 455th Expeditionary Aircraft Maintenance Squadron. U.S. Air Force photo by Tech. Sgt. Robert Cloys