Royal Air Force Operational Training Units (OTU) were training units that prepared aircrew for operations on a particular type or types of aircraft or roles. No. 1 (Coastal) Operational Training Unit RAF (1 OTU) 1 OTU was formed in 1940 as part of Coastal Command at RAF Silloth for training aircrew on coastal command patrol aircraft types until it was disbanded on 19 October 1943.No. 2 (Coastal) Operational Training Unit RAF (2 OTU) 2 OTU was formed in 1940 as part of Coastal Command at RAF Catfoss for training aircrew on coastal command twin-engined fighter and strike aircraft types until it was disbanded 15 February 1944.No. 3 (Coastal) Operational Training Unit RAF (3 OTU) 3 OTU was formed in 1940 as part of Coastal Command at RAF Catfoss for training aircrew on coastal command aircraft