Lieutenant Humphrey was the pilot of a F4U-5NL Corsair Night Fighter with Composite Squadron 3 aboard the carrier USS Princeton (CVA-37). On 13 June 1952, while on a night reconnaissance mission south of Hungnam, Korea, his aircraft received a direct hit by anti-aircraft fire. He bailed out. The helicopter crew of LST 799 observed the burning wreckage, a parachute and a body under the parachute.

Humphrey 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.