Group Captain Jack Darby Espie was born on 1 May 1924 in Caulfield, Victoria. Espie enlisted in the Royal Australian Air Force in 1942, graduating as a pilot in June 1943. During the Second World War, he flew 34 operations with 76 Squadron Royal Air Force, receiving the Belgian Croix de Guerre with Palme d'Or. He also flew with 187 Squadron RAF, 246 Squadron RAF, and 466 Squadron RAF. In 1955 he was awarded the Queen's Commendation for Valuable Service in the Air (QCBA) and in 1969 he received a Distinguished Flying Cross (DFC).

Espie served in Vietnam during the Vietnam War, he was CO of 35 Squadron in Vung Tau from February to December 1968, during which time he flew 1363 transport sorties totalling 835 hours flying time. He retired from the Air Force in July 1974, after 32 years' service.