U.S. Air Force Staff Sgt. Rushad Stroman uses hand gestures to communicate with another Airman to find out if sufficient amounts of liquid oxygen have been loaded onto a C-17 at Charleston Air Force Base, S.C., Dec. 14, 2009. The 437th Aircraft Maintenance Squadron at Charleston AFB primarily performs flightline tasks to include daily mission launch and recovery, pre- and post-flight inspections, maintenance troubleshooting, aircraft systems repair and modifications. Sergeant Stroman is an aircraft electrical environmental technician with the 437 AMXS. (U.S. Air Force photo by James M. Bowman)(RELEASED)

U.S. Air Force Staff Sgt. Rushad Stroman adjusts a liquid oxygen value while servicing a C-17 at Charleston Air Force Base, S.C., Dec. 14, 2009. The 437th Aircraft Maintenance Squadron at Charleston AFB primarily performs flightline tasks to include daily mission launch and recovery, pre- and post-flight inspections, maintenance troubleshooting, aircraft systems repair and modifications. Sergeant Stroman is an aircraft electrical environmental technician with the 437 AMXS. (U.S. Air Force photo by James M. Bowman)(RELEASED)