Wing Commander John Bell, a bomb aimer, described a sky filled with bursting shells and said: “It really only needed a tiny piece of a shell fragment to hit the engine to catch on fire – and that would be it.”

He also spoke of feeling that no one cared later on, explaining: “After the war we just got used to not thinking about it, and never even talked about it. Nobody asked us, and so it went on.”

Another veteran, Flight Sergeant Jack Watson, said he had been married for 35 years before his wife discovered that he had served in Bomber Command.

“It was only at our first reunion when we got together and my wife said to me: ‘You never told me any of this, I didn’t know this’… If you mentioned you were in Bomber Command, you were looked at as though you were a murderer,” he said.

Some said they were dismayed by the verdicts of some historians. Squadron Leader George “Johnny” Johnson, a bomb aimer, said: “Even now, if I met one I’d ask them ‘were you there, were you personally aware of the circumstances and conditions of that time?’ The answer to both those questions is no – so keep your bloody mouth shut.”