U.S. Army Warrant Officer Travis Wilson, 5th Battalion, 159th Aviation Regiment, conducts shut down procedures aboard a CH-47 Chinook after an aerial reconnaissance mission during Exercise Vibrant Response at Camp Atterbury, Ind., Aug. 19, 2011. Vibrant Response is the largest chemical, biological, radiological and nuclear (CBRN) response exercise designed to prepare expeditionary units focused on responding to domestic CBRN incidents.