U.S. Air Force C-17 Globemaster III aircraft participate in a large formation exercise over the coast of Charleston, S.C., Dec. 21, 2006. Twenty C-17s, assigned to the 437th and 315th Airlift Wings, Charleston Air Force Base, S.C., took part in the largest formation in history from a single base while demonstrating strategic airdrop capabilities of the U.S. Air Force.