In 1945, British prisoners held in the German castle had the ingenious idea of using bed slats, floorboards and sleeping bags to build a cock glider to fly them out.

They designed the plane in secret, making the tools they needed out of bed board handles, and making blades from gramophone springs, away from the eyes of German guards.

A concrete-filled bathtub, to be dropped five storeys before crashing into the floor was to have provided a catapult for the launch.

But the glider never actually took to the skies as its flight was postponed by British escape officers who feared the SS would order a massacre of any escapees who were caught.

Fifty-five years on, the POWs' plane was recreated by a team of television documentary makers from the Channel 4 series "Escape from Colditz".

And the original designers watched as the modern version prepared to take off from RAF Odiham in Hampshire.

Weather blow

But in the event, the plan was foiled by high winds, which forced organisers to postpone the flight.

Instead, the veterans had to be content to inspect the wooden glider on the ground.

Bill Goldfinch, the prisoner who had the original idea, said: "It is a huge disappointment not to see the plane airborne after all these years, but we have been promised we will get another chance."

Mr Goldfinch, who now lives in Salisbury, Wilts, was imprisoned for two and a half years in the supposedly inescapable castle.

"Although it is a magnificent effort by those who built this plane, what cannot be recreated are the conditions in which we built the original and the need we had to finish it," he said.

"My one regret is that the original never flew. If we had been in Colditz a bit longer then maybe she would've got up."

'Meticulous job'

The POWs used every scrap of wood they could find in the prison and used cotton prison sleeping bags for the skin of the glider.

Flt Lt Best, 87, another veteran who helped build the original, said: "I was perfectly certain that it would fly, and the meticulous job they have done in reconstructing it from the original plans is very impressive.

"Obviously they had tools that we could only dream about at the time, and the standard of materials are far higher because we had to use what was available."

Neil Fripp, of Southdown Aero Services, who helped build the new plane said: "It is very frustrating but the high wind will just not let us do it. It could flip over on take-off and we do not want to take the risk."

Colditz castle in Saxony became famous by Major Pat Reid's book The Colditz Story and a subsequent film starring Sir John Mills made in 1954.

Between 1941 and 1945, 1,500 Allied prisoners were held in 700 rooms at Colditz.