A Dedicated Crew Chief from the 311th Aircraft Maintenance Unit refuels a 311th Fighter Squadron F-16 Viper, April 30, 2019, on Hill Air Force Base, Utah. Between April 22 and May 3, the 311th FS conducted 174 sorties in support of student pilot training and dissimilar air combat training with the F-35 Lightning II. (U.S. Air Force photo by Staff Sgt. BreeAnn Sachs)