Guardian of Freedom
Staff Sgt. Derek, aerospace propulsion craftsman, verifies the fuel flow from an E-3 Sentry airborne warning and control system aircraft’s auxiliary power unit at an undisclosed location in Southwest Asia Feb. 24, 2015. The Sentry Aircraft Maintenance Unit is a group of guardians who blend several special powers, ranging from radar to hydraulics, and band together to ensure the E-3 Sentry AWACS maintains its operational capability. Derek is currently deployed from Tinker Air Force Base, Okla., and is a native of Waterboro, Maine. (U.S. Air Force photo/Tech. Sgt. Marie Brown)