Six veterans who famously broke free from a POW camp in World War II are meeting at the Imperial War Museum Duxford, Cambridgeshire, on Saturday.
The two veterans with mock-ups of some escape equipment
Their daring was immortalised in the classic 1963 film The Great Escape, starring Steve McQueen.
The escape took place in March 1944 when 76 Allied prisoners of war escaped from the Stalag Luft 3 camp.
Only three managed to reach safety and of the remaining 73 who were recaptured, 50 were shot.
The survivors are gathering at Duxford to reminisce and to launch a new book titled Lie in the Dark and Listen, which was written by Flight Lieutenant Ken Rees - who was part of the inspiration for McQueen's character Hilts "The Cooler King" in the film.
Sq Ldr Bertram James had been based at RAF Honington
Flt Lt Rees himself was caught in the tunnel.
Also at the public book-signing event will be Squadron Leader Bertram James, who had been based at RAF Honington in Suffolk.
He managed to escape, but was later recaptured.
An escape committee was formed at the camp in spring 1943 and the escape plan hatched under the leadership of Squadron Leader Roger Bushell.
Tom, Dick and Harry
Three tunnels, codenamed Tom, Dick and Harry, were started in April that year.
The tunnels were dug to a depth of 30ft and shored up with wooden boards from the prisoners' beds.
The Great Escape was recently made into a computer game
Some guards co-operated in supplying railway timetables, maps, and official papers needed by the escapees.
One of the tunnels, Tom, was only 10ft from completion when it was discovered.
The prisoners then focused their efforts on Harry, depositing the sand in the partially excavated tunnel named Dick.
Measuring over 300ft long, Harry was finally completed in March 1944.