In May 1943 the battalion transferred from the 1st Airborne Division to 6th Airlanding Brigade, of the newly formed 6th Airborne Division. He was a platoon commander in Major John Howard's 'D' Company "coup de main" that captured the Caen canal and Orne river bridges during Normandy landings on 6 June 1944. The task was to seize Bénouville bridge, now known as Pegasus Bridge, over the Caen canal and Ranville bridge, now known as Horsa Bridge, over the River Orne. Sweeney and his No. 23 platoon's objective was, with two other platoons, to capture the Ranville bridge.