Gen. Arnold W. Bunch, Jr., commander of Air Force Materiel Command, left, holds the Air Force Sustainment Center provisional flag with Lt. Gen. Gene E. Kirkland, right, during a change of command ceremony at Tinker Air Force Base, Oklahoma, Aug. 17, 2021. Kirkland is retiring after more than 33 years of active service. (U.S. Air Force photo by Paul Shirk)