Aircraftsman Aaron Kouyoumtzoglou, Royal Australian Air Force 36th Squadron aircraft technician, reconnects an auxiliary power unit to a C-17 Globemaster III aircraft trainer April 19, 2016, at Joint Base Lewis-McChord, Wash. The auxiliary power units is used to start a C-17’s four jet engines and provide power to the plane during flight. (U.S. Air Force photo/Senior Airman Jacob Jimenez)