He transferred to the Air Section of the Southern Rhodesia Defence Force in July 1936 and this became the Southern Rhodesian Air Unit on 1 April 1938. Holderness was awarded his wings on 13 May 1938.
He travelled to England with a draft of Southern Rhodesians in July 1940, landing in Liverpool on 13 August. He was commissioned in the RAFVR and he arrived at 5 OTU, Aston Down on 20 August.
After converting to Hurricanes, Holderness joined No 1 Squadron at Northolt on 4 September. He destroyed a Do 17 three days later. He moved to No 229 Squadron at Northolt on 17 October.
After rejoining the Southern Rhodesian Forces in August 1945, Holderness returned to Rhodesia and farmed there until 1971. He sold his farm and worked in the family law business. He was killed in a road traffic accident near his home in South Africa on 15 April 2008, aged 96.
Holderness had two younger brothers who were wartime RAF aircrew. Both survived the war.
