Ensign Loomer was the pilot of a F4U-4 Corsair fighter with Fighter Squadron 24 aboard carrier USS Valley Forge (CV-45). On 19 March 1951, while on a combat mission of strafing enemy positions near Kojo, North Korea, his aircraft was struck by anti-aircraft fire and crashed. He was listed as Missing in Action and was presumed dead on 21 April 1954. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Loomer was awarded the Air Medal, the Purple Heart, the Combat Action Ribbon, 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.