The President of the United States of America, authorized by Act of Congress, July 2, 1926, takes pleasure in presenting the Distinguished Flying Cross to Technical Sergeant Donald C. Lyles, United States Air Force, for extraordinary achievement while participating in aerial flight as an AC-119K Flight Engineer near Dak Seang, Republic of Vietnam on 6 April 1970. On that date, Sergeant Lyles and his crew supported the beleaguered outpost of Dak Seang on a daylight mission, flying cover for fighter-bomber strikes. Sergeant Lyles’ expert monitoring of aircraft systems allowed the gunship to bring the hostile positions under accurate fire resulting in the breaking up of two troops in contact situations and the silencing of a mortar position. The professional competence, aerial skill, and devotion to duty displayed by Sergeant Lyles reflect great credit upon himself and the United States Air Force.