Tech Sgt. Louis Matos, 380th Expeditionary Aircraft Maintenance Squadron hydraulic systems specialist, troubleshoots a KC-10 Extender at Al Dhafra Air Base, United Arab Emirates, Mar. 5, 2019. Hydraulic systems specialists are responsible for maintaining fluid-, air- or gas-pressured devices on aircraft. (U.S. Air Force photo by Senior Airman Mya M. Crosby)