On 25 December 1966, while operating as part of the
Far East Strategic Reserve,
Stuart was the first ship to fly the
Australian White Ensign. The Australian White Ensign did not officially replace the British
White Ensign as the
ensign flown by RAN ships until 1 March 1967. From late 1968 until 1969,
Stuart was designated Flagship of the RAN, while the aircraft carrier underwent a major refit. During April and May 1970, she carried out escort duties for the
Royal Yacht Britannia during the visit to Australia by
Queen Elizabeth II and the
Duke of Edinburgh. Following the destruction of
Darwin by
Cyclone Tracy in December 1974,
Stuart was one of thirteen RAN ships deployed as part of the humanitarian aid mission
Operation Navy Help Darwin.
Stuart sailed from Sydney on 26 December.
Stuart, along with HMA Ships , , and , visited the United States in 1976 for the
nation's bicentennial celebrations. In 1979,
Stuart entered dock to undergo a half-life modernisation refit valued at A$50 million. This included upgrades to weapons and systems, reinforcement of the hull, and improvements to seakeeping and habitability. The main improvement was the installation of the Australian-developed
Mulloka sonar system. Delays and cost increases meant that
Stuart did not re-enter service until 1983. In January 1984,
Stuart became the first major RAN warship to be homeported at
Fleet Base West in Western Australia. Between May 1984 and September 1986, the ship was deployed to South East Asia three times. A six-month refit began in February 1987, followed by a six-month assignment to the training squadron with and .
Stuart returned to Western Australia in November 1988.
Stuart was originally intended to leave service in early 1991,but the
Iraqi invasion of Kuwait saw
Australia commit several s to the United States-led Coalition.
Stuart was kept in service and deployed to South-East Asia from February to May 1991 in lieu of the deployed frigates. ==Decommissioning and fate==