Col. Sterling Tree, 339th Flight Test Squadron commander, parks an F-15 after completing his final flight as the unit's commander 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)