War hero George “Johnny” Johnson relived his days as a member of the legendary Dambusters squadron at a Second World War charity evening on Friday.

Nearly 60 people gathered in the White Horse pub in Compton Bassett to hear Sqn Ldr Johnson, 86, talk about the RAF mission to bomb Germany’s hydro-electric dams in 1943 using the revolutionary bouncing bomb specifically designed for the task by pioneering scientist Barnes Wallis.

The evening, which included the auction of two prints of the Lancaster aircraft that flew in the raid and a book about the mission, each signed by Mr Johnson, raised £1,000 for the 617 Squadron Aircrew Association, the squadron formed to breach the dams.

Guests included a Second World War rear gunner from Lancasters, ex-members of 617 Squadron and serving and ex-servicemen, including those from RAF Lyneham.

Mr Johnson, a retired teacher, said: “I do not volunteer to come and talk to people, but if people ask me to then I know they are interested and I accept.

“It is a good old nostalgia trip for me and I enjoy it. People come up with interesting questions.”

A highly secret task, Operation Chastise set out to destroy three dams in the Ruhr Valley – the Mohne, the Eder and the Sorpe – and so damage a vital source of power to Germany’s industrial heartland.

Mr Johnson was a 21-year-old bomb aimer when he took part in the raid.

He said: “We did not know until right before what we had been training for. The general feeling was that we would be attacking German ships.

“I flew with the American pilot Joe McCarthy who was big in size, big in personality and big in piloting, which was a good thing.”

Overall the mission was hailed a success after the Mohne and Eder dams were destroyed. But it was at the cost of eight aircraft and 53 crew members.

“Barnes Wallis actually cried in the briefing after the operation and said he had led the others to their death,” said Mr Johnson.

“But those people set off knowing it could be a consequence of the war and to some degree that consoled him.

“I had absolute confidence in Joe and I never thought I was not coming back.”

The squadron was immortalised by the 1954 film Dam Busters, based on a book by Paul Brickhill.

The Lord of the Rings director Peter Jackson is to remake the film using details of the mission that were still classified when the original film, starring Richard Todd, was made.