Tech. Sgt. Shawn Summers, a 315th Maintenance Group member and C-17 Globemaster III crew chief here at Joint Base Charleston, S.C., screws in a cover plate on the body of a C-17 yesterday on the aircraft ramp here at Joint Base Charleston, S.C. The 315th MXG provided operational flight line coverage yesterday while the 437th Maintenance Group took part in the active duty’s wingman day activities.