On the night of May 16, 1943, 617 Squadron flew Lancasters at 60 feet over Germany to deliver Barnes Wallis's bouncing bomb and breach the dams of the Ruhr Valley.
On the night of May 16–17, 1943, 19 Lancaster bombers and 133 airmen executed Operation Chastise, breaching Nazi Germany's Ruhr valley dams with Barnes Wallis's revolutionary bouncing bomb.