In September of 1943 the Australians para-dropped two detachments of field artillery in support of the USA 503rd Parachute Regiment in New Guinea.  The Autralians did not partake in another parashute operation until December 1969 when the 3rd S.A.S. Squadron conducted an operational parachute descent to the east of Phuoc Tuy Province during the Vietnam War.  However, there is no doubt that if they were required to do so, the Australians would have conducted any para operations asked of them.  Therefore the US transport planes are made available to them for use in hypothetical scenarios.