Returning to Australia , Headlam became Deputy Chief of the Air Staff ( DCAS ) on 26 January 1965 . He was appointed a Companion of the Order of the Bath ( CB ) " in recognition of distinguished service in the Borneo Territories " on 22 June . His tenure as DCAS coincided with the most significant rearmament program the Air Force had undertaken since World War II , and with manpower shortages stemming from this expansion and from Australia 's increasing involvement in the security of South East Asia . The first RAAF helicopters were committed to the Vietnam War towards the end of his term , and he travelled to Saigon with the Chief of the General Staff , Lieutenant General Sir John Wilton , in March 1966 to plan the deployment . The year before , Wilton had recommended to Air Marshal Murdoch , the Chief of the Air Staff , that two Iroquois be sent to Vietnam for familiarisation purposes ; Murdoch had rebuffed Wilton , and the RAAF helicopter squadron was considered underprepared for its army co @-@ operation role when it finally did deploy . Headlam succeeded Air Vice Marshal Douglas Candy as AOC Support Command , Melbourne , on 8 August 1966 . Support Command had been formed in 1959 , by merging the RAAF 's former Training and Maintenance Commands . On 1 January 1968 , Headlam was posted to London as Head of the Australian Joint Services Staff . He served as an Extra Gentleman Usher to the Queen from 17 November 1970 to 5 June 1971 .