DAEGU AIR BASE, Republic of Korea -- Senior Airman Kevin Doan, a security forces member from the 353rd Operations Support Squadron, checks the seal on his gas mask during a simulated gas attack here March 22. More than 350 members and several aircraft assigned to the 353rd Special Operations Group spent nearly a month at Daegu Air Base, Republic of Korea, testing and assessing their wartime skills necessary to survive and operate in any environment. (U.S. Air Force photo by Tech. Sgt. Aaron Cram)