A U.S. Air Force C-17 Globemaster III clears the drop zone after air dropping a 20-ton U.S. Army M-551A1 Sheridan tank during an air-drop exercise at the Sicily drop Zone. Fifty-five tons of heavy cargo and 204 paratroopers were successfully air-dropped from six C-17's to demonstrate the utility of the U.S. Air Force's newest airlifter to meet the Army's brigade air-drop requirement