After retiring from military life in March 1957, he chaired community and welfare organisations, serving as Federal President of the Air Force Association for ten years.

[1][2] In January 1924, he transferred to the Royal Australian Air Force as a flying officer, undertaking the pilots' course at RAAF Point Cook, Victoria.

[1][2] Promoted to squadron leader, McCauley was posted a third time to Britain in 1933, graduating from RAF Staff College, Andover, and qualifying as a flight instructor at Central Flying School, Wittering.

[15][16] Deployed to forward bases on the Malay Peninsula, McCauley's Hudsons were the first Allied aircraft to spot Japanese troop transports converging off Indochina on 6 December, and they attacked the fleet in the face of heavy defensive fire.

[1][15] By Christmas, as the Allies retreated from Malaya, Sembawang was "the busiest airfield on Singapore island", with two Dutch Glenn Martin bomber squadrons as well as the remnants of the Hudson units, along with Nos.

[8][18] With his available aircraft augmented by Hawker Hurricanes and Bristol Blenheims, he conducted attacks on enemy convoys before evacuating the area on 15 February 1942, the day that Singapore surrendered.

After communications between himself and local RAF group headquarters were cut, McCauley was left to his own devices to make final arrangements for the demolition of equipment and departure of staff.

[20] McCauley led the last party to depart Palembang, and was praised for organising the safe passage back to Australia of many Commonwealth air force personnel.

[8][19] After his return to Australia late in February 1942, McCauley briefly served as Senior Air Staff Officer at North-Western Area Headquarters in Darwin, Northern Territory.

He took up the position of Deputy Chief of the Air Staff (DCAS) in May, and was appointed a Commander of the Order of the British Empire (CBE) in the 1943 King's Birthday Honours, promulgated on 2 June.

10 Group at Nadzab in March 1944, McCauley learned that unless the Australian formation was able to increase its operational rate of effort, its units would be withdrawn from their forward airfields.

As a result, RAAF Headquarters increased the supply of pilots and equipment to the group, which was then able to meet, and later exceed, the rate of effort achieved by comparable US Fifth Air Force units.

[27] Among a small coterie of wartime RAAF commanders earmarked for further senior roles, McCauley retained his rank of air commodore following the cessation of hostilities.

According to official RAAF historian Alan Stephens, McCauley was "just as ready to become CAS in 1952 as he was in 1954", and a contemporary observer declared that "seldom has a better-equipped officer led a branch of the Australian services".

McCauley identified Malaya and Indochina, particularly Vietnam, as likely areas for future RAAF deployments, advocating a continued presence in Singapore in view of its strategic importance to the defence of Australia, as he had witnessed first-hand during World War II.

[39] Some of his senior commanders had urged replacing the Canberra with Avro Vulcan heavy bombers, but McCauley did not pursue this option, preferring to concentrate in the short term on new fighter technology.

He aimed to make Darwin the "main Australian base for war" and a launching point for deployments to Southeast Asia, rather than simply a transit station.

[43] After his retirement from the RAAF on 18 March 1957,[44] McCauley became active in community welfare organisations, chairing campaigns for the National Heart Foundation, Freedom From Hunger, the Royal Humane Society, and the Cancer Council in the late 1950s and early 1960s.

[1][8] In this role he endorsed the initial proposal, featuring monumental statues of airmen and ground crew, for the Royal Australian Air Force Memorial to be located on Anzac Parade, Canberra.

The design ultimately approved by the final selection panel was an abstract sculpture that was subsequently described as reflecting a "comprehensive failure to understand the nature of air force service".