Nearly a century ago, they took to the skies over the Western Front in their flying machines. None of them returned alive.

Now a new memorial is being unveiled on Friday to the brave men who learned to fly over the fields of West Norfolk.

The unveiling is being performed by Sir Michael James Beetham, a decorated second world war bomber pilot who went on to become marshall of the RAF.

'It's a memorial to the men and women who served at Narborough Aerodrome during the first world war,' said David Burchell, chairman of Narborough Parish Council, which has organised the memorial.

'The Royal Naval Air Service, RFC, RAF and American aero squadrons as they trained at Narborough.'

After completing their training, pilots were sent to the Western Front, where they flew reconnaissance flights above the German lines.

Casualties were high in the flimsy biplanes – whose pilots did not wear parachutes to escape from their stricken craft.

Mr Burchell said research by local historians had not uncovered a single airman from Narborough-based 59 squadron who had returned alive.

As well as those lost to rifle fire and enemy aircraft, a further 41 died in crashes in the Norfolk countryside. Engine failure was most commonly to blame for crashes.

A guard of honour from nearby RAF Marham will be attending the unveiling ceremony, organised by the parish council, on Friday afternoon.

After the dedication, there will be a fly-past by one of the base's Tornado jets.

The memorial is being sited near to the entrance of the former base in Chalk Lane, south of the village, opposite the Marham turning.

Once covering almost 1,000 acres, with 30 acres of buildings, Narborough was the biggest first world war aerodrome in the country.

It was abandoned and its runways ploughed over for good in 1919, the year after the Armistice, when its last squadron left for RAF Bircham Newton, near Fakenham.

German prisoners of war, accommodated on the base while they were sent to work in the fields, were also repatriated.

Nothing now remains of the former base, which has reverted to farmland. The last of its seven large aircraft hangars was demolished in the 1970s.