 Hancock retired from the Air Force in May 1965 after completing his term as CAS , which the government had extended for twelve months beyond its original three years . Having followed two fellow Royal Military College graduates — McCauley and Scherger — in the role , he was succeeded by another former Duntroon cadet , Alister Murdoch . Hancock 's name was put forward as a successor to Scherger when the latter 's term as Chairman of the Chiefs of Staff Committee completed in May 1966 , but Prime Minister Sir Robert Menzies preferred General Sir John Wilton for the position . Later the same year , Hancock took over as Commissioner @-@ General for Australia at Expo 67 in Montreal , Canada , following the sudden death of the previous appointee , Vice Admiral Sir Hastings Harrington . In 1975 , prompted in part by the fall of Saigon in April that year , Hancock co @-@ founded the Australia Defence Association as an independent think tank for defence matters , and chaired its Western Australian chapter . He was also active in the Royal Commonwealth Society , and published an autobiography , Challenge , in 1990 . Hancock continued to fly in retirement , joining his cousin Lang , also a pilot , in promoting the Pilbara mining district . Val Hancock died in Perth on 29 September 1998 , and was survived by his wife and three children . He is commemorated by Sir Valston Hancock Drive at Evans Head . 
