By April 1944, No. 463 Squadron had begun to concentrate on targets in France and Belgium as the Allied air campaign shifted focus from strategic bombing to destroying airfields and disrupting lines of communication prior to the invasion of the continent. On 8 May, Brill was the bombing controller for a raid on an airfield near Brest. The controller was required to arrive ahead of the main Allied force, check that flares marking the target were in place, and warn his fellows if they were bombing inaccurately. By the time Brill had completed this task and gone in himself to attack, the ground defences were fully alert and peppered his Lancaster with 140 bullet holes, but he refused to take evasive action until he had delivered his bombload. Promoted to acting wing commander, Brill assumed control of No. 467 Squadron on 12 May, following the death in combat of its previous commanding officer, Group Captain John Balmer. According to the official history of the RAAF in World War II, Brill "proved a very worthy successor to Balmer both in administration and in the dashing type of leadership which had brought the Waddington squadrons to the fore in No. 5 Group". He was awarded the Distinguished Service Order on 19 May for "leadership, skill and gallantry of the highest order" and "his determination to make every sortie a success" in spite of frequent damage to his aircraft. Early the next month he led No. 467 Squadron in raids on Axis radar stations in northern France. The unit was in action on D-Day over Pointe du Hoc and, later, clearing a corridor for Allied troops advancing up the Cherbourg peninsula.