The son of an airman shot down during the Second World War is trying to trace the family of a Bierley man who was killed in action with his father.

Ken Cothliff will pay tribute to his father William "Scotty" Gracie at this year's Yorkshire Air Show and hopes the relatives of Mr Gracie's two British air crew can join him.

Mr Gracie, who was a Canadian, was flight engineer on a Halifax bomber of the 425 Alowette squadron of the Royal Canadian Airforce that took off from Tholthorpe in North Yorkshire after the D-Day invasion to destroy caves where the Germans had stored V1 flying bombs.

The aircraft was shot down at St Leu D'esserent on August 5 1944. Mr Gracie and five other air crew including warrant officer Brian Clark from Bierley and pilot officer Graham Beresford, who was married and lived in Harrogate, were killed.

Mr Cothliff, 60, who lives in Yeadon, said: "I never actually met my father, as I was born a few days after he was killed. The pilot, Gerald Philbin, and an air gunner survived. Mr Philbin wrote me a letter and gave me all the information he could.

"He said the two Englishmen were replacements for two Canadians who were killed but we know very little about Brian Clark. There was an address but it is very hard to read.

"My dad was 23 and him and my mum were engaged. I was born about a week after my dad was killed and was adopted from Stawberry Fields in Liverpool."

The men's bodies were found 10 days after their deaths by the Resistance in St Maximin, France, where they were buried and later they were reinterred in an American cemetery in France.

In 1947 their remains were moved again to a Canadian cemetery in Dieppe and looked after by the War Graves Commission.

"I am desperate to find the relatives of the British men," said Mr Cothliff, who is director of the Yorkshire Air Show and runs Air Supply Aviation Store in Yeadon.

"As time goes on I do not think it will be much longer before people don't remember these things. I am at the stage where this is my last opportunity to find the families and bring them to the air show as our guests.

"Hopefully their families will still be living in Yorkshire so it would be fabulous if we could meet up and remember the three of them on the 60th anniversary of that tragic mission."

This year's Yorkshire Air Show on August 21 and 22 at Elvington Air Field has been named "The Classic Bomber Meet" as a tribute to the men of Bomber Command who lost their lives on the ill-fated mission and will be one of the biggest gatherings of bomber aircraft in the UK show season.

Three of the greatest bombers of World War Two, the Lancaster, Flying Fortress and the Halifax, will be at the airfield for only the second time in 60 years.

Warrant officer (air gunner) Brian Clark, who was a member of the Royal Air Force Volunteer Reserve, was 23 years old when he was killed and was the son of Fred and Margaret Clark, who lived in Bierley.

The surviving pilot of the doomed plane wrote an address for Mr Clark in his letter but Mr Cothliff said the handwriting was difficult to read. "It looked like 'Roondock Avenue," he said.

Anyone who can help Mr Cothliff trace the families of his father's colleagues can call him on (0113) 250 9581.

Tickets for the Yorkshire Air Show are available at reduced rates in advance by calling the show's hotline on (01759) 305851.