It's three-quarters of a century since 617 Squadron flew off to break open major German dams in a mission to hit Nazi Germany's war production.
The raid in May 1943 called for pinpoint accuracy in dropping bouncing bombs from the speeding Lancaster bombers, so the devices could skip over the dams' defences in the water and strike the dam walls.
Wing Commander Guy Gibson, who led the squadron, was killed on another mission later in the war, in September 1944. He was just 26.
A total of 133 aircrew set out on the raid in 19 Lancaster bombers from RAF Scampton, led by Wing Commander Gibson, but 53 men were killed on the mission and three were captured.
The four-engine propeller Lancaster, which carried Barnes Wallis's revolutionary bouncing bombs, was advanced for its time.
Barnes Wallis was the inventor of the bouncing bombs which breached the Mohne and Eder dams in Hitler's Germany.
The name given to the Dambusters mission, in which today's sole survivor Johnny Johnson was a bomb aimer, was Operation Chastise.
The Lancaster bomber has often been seen flying in formation with two other RAF Second World War aircraft - the Hurricane and Spitfire fighter planes.
The anniversary is a time for remembering those who made the ultimate sacrifice in the Second World War.