USMA Class of 1950, First Lieutenant Dennis was the pilot of a F-84E Thunderjet fighter with the 428th Fighter Bomber Squadron, 474th Fighter Bomber Group. On September 28, 1952, while on a combat mission, his aircraft was shot down by a MiG-15. He was listed as Missing in Action and was presumed dead on December 31, 1953. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.