U.S. Air Force Staff Sgt. Melissa Butterfield, a loadmaster with the 817th Expeditionary Airlift Squadron, inspects an oxygen mask aboard a C-17 Globemaster III aircraft Aug. 18, 2011, at Incirlik Air Base in Turkey during a mission transporting equipment and supplies to Kandahar Airfield in Afghanistan. Loadmasters ensure cargo is secured and monitor emergency equipment.