He succeeded Leonard Cheshire as commander of No. 617 Squadron RAF in July 1944. 617 Squadron, the famous "Dambusters" squadron, specialised in low-level target marking and precision attacks. Under his command, the squadron bombed a series of V-1 storage sites and V-2 launching sites using Barnes Wallis's "Tallboy" 12,000 lb earthquake bomb. Tait was awarded a bar to his DFC for pressing home a low-level attack in a daylight raid on the Kembs Dam in southern Germany against fierce defensive fire despite having a damaged aircraft.