[1] It was tasked with training aircrew for Avro Anson, a British twin-engine, multi-role aircraft, and Bristol Beaufort, a British twin-engined torpedo bomber aircraft, from No.

3 (C) OTU was initially designated for training aircrew for Vickers Wellington, a British twin-engined, long-range medium bomber, and Armstrong Whitworth Whitley, a British medium bomber aircraft, however, slow progress with the construction of new airfields meant the Vickers Wellington and Armstrong Whitworth Whitley aircrew training went to RAF Kinloss, and later RAF Silloth, with the Bristol Beaufort aircrew training remaining at RAF Chivenor.

Initially, on the 30 November 1942, four of its Armstrong Whitworth Whitley aircraft, along with ground crew, moved in from RAF Cranwell.

Its role was to provide aircrew with reconnaissance training and by June 1943 its full complement of aircraft had arrived.

[4] 'O' Flight of was equipped with fourteen Avro Anson I aircraft,[5] and was tasked with the training of aircrew for general reconnaissance and particularly the use of Leigh Lights.

3 (Coastal) Operational Training Unit was equipped with numerous types and variants of aircraft:[8] The main airfield for the unit was RAF Chivenor however a number of different airfields were also used.