 In preparation for Operation Overlord, Nos 1 and 165 Squadrons formed a wing of Supermarine Spitfire IXs at Predannack to prevent Luftwaffe aircraft from attacking Allied shipping.As the invasion convoy around Falmouth assembled, the Spitfires gave constant fighter cover.179 Squadron equipped with Wellingtons and the Czechoslovak-crewed 311 Squadron equipped with Liberators undertook anti-submarine patrols over the Bay of Biscay and approaches to the English Channel.