Graduate, U.S. Naval Academy, Class of 1947.

Lieutenant Junior Grade McCoskrie was the pilot of a F4U-5N Corsair night fighter with Composite Squadron 3, aboard the carrier USS Valley Forge (CV-45). On 13 February 1951, while on a night combat heckler mission near Yontae-ri, Korea, contact was lost and he was listed as Missing in Action. He was presumed dead on 16 April 1954. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

McCoskrie was awarded 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.