Paul Dean, left, and James Dean PA Images

Cover Image: Paul Dean, left, and James Dean, will retrace the 250km that Second Lieutenant Jock Tullis took after he escaped. (Pictures: PA Images)

A father and son will be running the route their prisoner of war ancestor took as he escaped from a German camp a century ago - to raise funds for the Royal Air Force Benevolent Fund.

James Dean and his father Paul, 53, from Devon, will retrace the 250km that Second Lieutenant Jock Tullis took after he escaped from the prison in Holzminden on July 23, 1918.

James says the aim is to replicate the path his great-grandfather took 100 years ago as closely as possible as they head from the German town to Losser, on the Dutch border.

He said: "When we found his memoirs, although it doesn't give the exact route, it gives us a rough route and I think that is what really sprung the idea in dad's head.

His great-grandfather, who was in the Royal Flying Corps, spent two years as a prisoner of war after he had to land his two-seater Sopwith behind enemy lines.

Second Lt Tullis had been on a reconnaissance mission around 80 miles from the border when disaster struck and his plane was shot at.

"While he was flying, his observer was shot in the jaw, and his own gun jammed and they started making their way back and then the engine failed," James said.

"He had no option but to land, but it was seen by hordes of Germans, and he had absolutely no chance."

Eventually ending up at the camp in Holzminden, imprisoned along with more than 550 other officers, the inmates spent nine months constructing a tunnel to escape.

James explained that there were 86 on the list to break out during the first attempt - but the 30th man got stuck, bringing the escape to an end.

His great-grandfather made it out, as one of the lucky 29, and spent two months with two other individuals trying to make it to safety without getting caught.

"He was out there quite a while - 250km for us just running it straight - we can do it in a week.

"But when you know you have got to keep moving because you have got the guards from the camp behind you and avoid every other German out there ... it must have been a really, really scary time."

He said his great-grandfather arrived back in the UK and received a signed letter from King George V which thanked him for his service and welcomed him home.

Second Lt Tullis also returned to discover he was now an officer in the newly formed Royal Air Force - with his commission note stating this happened on April 1 1918, the day the world's first independent air force was created.

Father and son's journey will start on Monday with a short 6km run, just after midnight - the time his great-grandfather escaped.