Major Gilardi was the pilot of a F4U-4B Corsair fighter with the Marine Fighter Squadron 312, Marine Air Group 12, 1st Marine Air Wing. On 1 January 1952, while on a combat mission near Chorwon, Korea, his aircraft received a direct hit by anti-aircraft fire and caught fire. He bailed out and was taken Prisoner of War. He died while a prisoner on 6 January 1952. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Major Gilardi was awarded the Distinguished Flying Cross, the Air Medal with Gold Star, the Purple Heart, the Combat Action Ribbon, the Prisoner of War Medal, 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.