An U.S. Air Force independent duty medical technician, left, with the 563rd Operations Support Squadron applies putty to simulate a wound on University of Arizona Air Force ROTC cadet Matthew Helm, who volunteered to play the role of a crash victim during an exercise for Angel Thunder 2013 at Davis-Monthan Air Force Base, Ariz., April 13, 2013. Angel Thunder is a joint service, interagency and multinational combat search and rescue exercise designed to provide training for personnel recovery assets in a variety of scenarios to simulate deployment conditions and contingencies.