There will be a flypast by a Spitfire and a Mustang tomorrow (Saturday, September 19) before the unveiling of a memorial to the British and American World War II air crews who flew from RAF Debden. The planes are due between 1pm and 1.30pm.

William Clark, the Second World War pilot who will unveil the monument, will also arrive in a wartime Harvard aircraft used in the training of Hurricane and Spitfire pilots, at approximately 1.45pm.

The event is open to the public and there will be free parking at Carver Barracks from 1pm. The unveiling ceremony is due to start around 2.30pm.

Mr Clark will be wearing medals presented to him on Tuesday (September 15) by the Chief of the Air Staff at the Battle of Britain service at St Paul’s Cathedral. Though he earned them during the war, he only applied for them in order to wear them at the RAF Debden event. Officers representing the Royal Air Force and the United States Air Force and civic heads will attend along with service personnel and civilians who served at the former airbase.

Just after his 21st birthday, Mr Clark’s aircraft was shot down over the African desert and he was taken prisoner by the Germans.

He saw “little balls of fire” approaching him, fired by the anti-aircraft guns on the ground, and can distinctly remember the shock of the crash-landing after his plane was hit. Surviving the crash he then trudged in the desert’s midday sun wearing fur-lined flying boots, in heavy desert battle dress as he tried to evade the enemy.

Mr Clark said: “It wasn’t a very pleasant experience and of course there was the shock. I was only just 21 and suddenly I was not in my normal environment – in the sky, in an aircraft.

“Here I was wandering about all on my own in a vast expanse of rock and sand. It was very, very lonely. I’ve never been so lonely in my life.”

The memorial ground, prepared by Royal Engineers, fronts the original north-south runway. The memorial also contains the names of RAF Technical Training Command (1946-1960) and the RAF Police Depot (1960-1975).

There will also be a commemorate stone to the United States 4th Fighter Group which operated from the base between 1942 and 1945. And on view will be the recently discovered Pickett-Hamilton Fort, a concrete pillbox that can be raised mechanically, one of four designed to defend the runways.

The event coincides with national commemorations to mark the 75th anniversary of the Battle of Britain in which RAF Debden played a key role as part of 11 Fighter Group.

A new memorial ground has been created on the perimeter of the former airfield, now part of Carver Barracks, Wimbish, home of 33 and 101 Engineer Regiments EOD (Explosive Ordinance Disposal).

The memorial is the result of a campaign by Keith Braybrooke, the author of the book Wingspan which told the history of the base.

Mr Braybrooke campaigned for a monument to mark the presence of RAF Fighter Command.

After persuading Uttlesford District Council to fund the memorial, he died last year but he knew that the memorial would be built.

RAF Debden played a crucial role defending South East England and London during WW2, especially during the Battle of Britain. Among fighter aces who served at RAF Debden was Squadron Leader Peter Townsend, who commanded 85 Squadron.

The memorial has been designed and constructed by memorial masons Whitehead and Day.