U.S. Air Force Staff Sgt. Curtis Downer, 447th Expeditionary Aircraft Maintenance Squadron munitions systems specialist, cleans thread wells on a GBU-12 Paveway II laser-guided bomb Aug. 8, 2016, at Incirlik Air Base, Turkey. Thread wells are cleaned prior to installing the fin to ensure a safe and secure attachment. (U.S. Air Force photo by Senior Airman John Nieves Camacho)