Captain Casteel was the pilot of a F-84E Thunderjet fighter with the 182nd Fighter-Bomber Squadron, 136th Fighter Bomber Wing. On 21 January 1952, while on a combat mission, his aircraft received a direct hit by anti-aircraft fire. He was unable to bailout successfully. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Captain Casteel was awarded the Distinguished Flying Cross, the Air Medal with 4 Oak Leaf Clusters, the Purple Heart, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.