Captain Oyler was a crew member of a B-29A Superfortress Bomber with the 325th Bomber Squadron, 92nd Bomber Group. On 9 September 1950, while on a bombing mission, his aircraft was hit by anti-aircraft fire and exploded mid-air near Wolbong-ni. Five parachutes were seen. He was listed as Missing in Action and was presumed dead on 31 March 1954. 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 Oyler was awarded the Distinguished Flying Cross, the Air Medal with 5 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.