T.4 of 231 OCU at its
RAF Cottesmore base in 1970 231 OCU first formed in the aftermath of the
Second World War on 15 March 1947 at
RAF Coningsby. Initially the OCU was formed from a nucleus provided by No. 16 OTU and was tasked with training crews of the "wooden wonder", the
de Havilland Mosquito, in the light bomber and photo reconnaissance roles. Initial operational equipment was provided by Mosquito III and Mosquito B.XVI aircraft. In this role the unit lasted nearly three years before disbanding on 4 December 1949. In keeping with its previous role when the OCU reformed on 1 December 1951 it was to train
light bomber aircrews by redesignating
237 OCU. The aircraft used during the rest of the unit's operational service was the
English Electric Canberra, a British first-generation, jet-powered
medium bomber and most operational versions of that versatile aircraft were flown by the unit. It was reformed at
RAF Bassingbourn in
Cambridgeshire and it moved around various stations, including RAF Bassingbourn,
RAF Cottesmore Rutland and
RAF Marham in
Norfolk, during its operational existence. It was redesignated the
Canberra Standardisation Training Flight on 15 December 1990, but reverted to 231 OCU on 13 May 1991. 'D' Squadron was previously
No. 204 Advanced Flying School at Bassingbourn which was disbanded on 13 February 1952. 204 AFS was previously
No. 204 Crew Training Unit which was formed on 28 February 1947 at Cottesmore by redesignating an element of No. 16 OTU. 204 CTU was disbanded on 15 March 1947 at Cottesmore. ==Disbandment==