At the start of WWII, No. 220 Squadron operated patrols from Thornaby, switching from Ansons to Hudsons by late 1939. From May 1940, it flew anti-shipping missions off Norway and the Dutch coast, later relocating to Scotland in 1941 to target coastal shipping.
A detachment operated Fortresses in the Middle East briefly, while the main squadron converted to B-17 Fortresses in early 1942. Fortress FL459, code 'J', was delivered to Ballykelly on 20 August 1942 and went on to sink four U-boats during the war. In March 1945, it was reassigned to meteorological duties.
