Col. Sterling Tree, 339th Flight Test Squadron commander, greets friends and family after his final flight in an F-15 Sep. 20, 2018, at Robins Air Force Base, Ga. Tree is scheduled to relinquish command of the 339th FLTS to Lt. Col. John Lesho during a change of command ceremony. (U.S. Air Force photo by Jamal D. Sutter)