Staff Sgt Stewart Guethlein briefs passengers on how to properly don an oxygen mask May 15 during a semi-annual noncombatant evacuation operations exercise, Courageous Channel, at Yokota Air Base, Japan. Sergeant Guethlein is a loadmaster with the 36th Wing. Yokota's C-130 aircrew flew to Osan Air Base, Republic of Korea, picked up 50 noncombatants and returned. (U.S. Air Force photo/Airman Sean Martin)