Col. Peter Hofelich, 355th Maintenance Group commander, shakes the hand of Lt. Col. Christian Lawlor on Sept. 23, 2009, after he landed the last KC-135E Stratotanker at Davis-Monthan Air Force Base, Ariz., where the aircraft will retire after more than 50 years of active service. (U.S. Air Force Photo/Airman Jerilyn Quintanilla)