An aircraft engineer who restores historic Spitfire fighter planes that “all have a story to tell” has said they must be kept flying for future generations ahead of the 80th anniversary of D-Day.

Spitfires are famed for their role in the Second World War, from taking to the skies in the Battle of Britain to providing air support for the Allied troops in the Normandy landings 80 years ago.

More than 20,000 of the world renowned fighters were built around the war period, but it is estimated just 60 airworthy veterans remain.

Biggin Hill Heritage Hangar, nestled outside of London, is believed to be the world’s largest Spitfire restoration and passenger flight hangar, and the team are currently working to revive their 17th Spitfire to an airworthy condition since opening in 2011.

Alex Monk, 25, who works at the family business, said: “We’re at the point now of everything transferring out of living memory.

“The only link that future generations will get to this other than grainy pictures in textbooks will be seeing these machines.

“It’s actually this wonderful object that makes a lot of noise and does something and stands for an awful lot.”

At the hangar which lies on what used to be RAF Biggin Hill, the famous fighter station during the Second World War, several Spitfires are up for repair in the workshop.

“They all have a story to tell and it humanises it all,” Mr Monk said.

The Spitfire MK1a P9372 flew in the Battle of Britain and was shot down near Biggin Hill.

Its pilot William Watling survived suffering serious burns to his face and hands. The plane was shot more than 100 times and was excavated from Romney Marsh, in Kent, in the 1970s.

An engineer works on the restoration of a Spitfire inside the Heritage Hangar at Biggin Hill Airport in Kent (Gareth Fuller/PA Wire)

Bullet holes have been patched up with the plane’s debris they had hanging up in the next door workshop to “show a little bit of vintage,” engineer Gary Woodhouse said.

But he added owner Peter Monk – Alex’s father – spends his time “scouring the globe” for parts to restore the machines. “The more people want to spend and they want to buy – without these parts you couldn’t do it,” he explained.

“Things are always out there … you’ll find with the older generation, which we’re now losing, keep these sorts of things in their shed or on their mantelpiece. To them, it’s prosperity (sic), but now they’re the bits we need.”

The 56-year-old from Swanley began working at the hangar six years ago and admits “it’s not your everyday job”.

Mr Woodhouse added: “At first you enjoy the novelty factor, it’s great, it’s huge. The interest has always been there with war birds, with this type of aircraft, and especially the history and the older generation which we’re losing.

“You are humble, it is iconic to work around them, it is not your everyday job. You’ve got to be proud, you are keeping history alive.”

Also onsite is a D-Day veteran Spitfire being restored after it had a wing taken off in a crash landing into an oak tree at Biggin Hill about 12 years ago. The Spitfire MK912 was originally flown by Czech pilot and squadron leader Tony Liskutin on June 6, 7 and 8 1944 over the British sector providing ground support.

Alex Monk recalled the day Mr Liskutin was reunited with his aeroplane again on a visit to the hangar on March 25 2013.

“He sees his machine come up alongside and you see the tears and the joy on his face from that, because he wasn’t expecting it. That was really great to see,” the Maidstone resident said.

He added: “But there aren’t that many D-Day veteran Spitfires left out there. There’s probably less than 10 that I know of that have got genuine D-Day history.”

Chief engineer Franco Tambascia is also working on the D-day Spitfire as the latest in his 33-year-career of working with old warplanes.

“We’re hoping to run the engine in six weeks even though there’s a lot missing,” he said.

Biggin Hill Heritage Hangar
An engineer works to prepare invasion stripes on a Spitfire outside the Heritage Hangar at Biggin Hill Airport in Kent, ahead of the 80th anniversary of D-Day in June (Gareth Fuller/PA Wire)

The 49-year-old said “it’s a real privilege” to work on the historic planes.

He added: “If it wasn’t for these aircraft and every aircraft like this we wouldn’t have won the war.

“So we’ve got to keep the heritage going to make sure that (in) the future, everybody, the younger generation would understand what happened and what the pilots went through.”

The Biggin Hill team are preparing to mark the D-Day anniversary by flying their Spitfire fleet with freshly painted invasion stripes on their wings, in a nod to the efforts in the lead up to the offensive.

On painting the stripes, Mr Monk said: “We’re quite authentic in the way that we do it. If you see any wartime pictures they weren’t out there with masking tape and spray guns. It was brooms, paint brushes, paint was put on aeroplanes with whatever you could find.

“We’re paying true homage to how it would have been done in period, down to painting them outside.”

Mr Monk also plans to take the D-Day Spitfire in the workshop over to Normandy for the D-Day anniversary. He goes to France every year for the commemoration, where his great, great uncle came ashore and was killed taking the Hillman bunker complex on June 6 1944.

Of the 80th anniversary this year, he said: “For me, every year is as important. I think this one being the 80th is a big thing, but I think it’ll probably be the last time that you’ll have many veterans there in physical form.

“So to get out there and try and meet some that I haven’t met before and gather the last stories up before they all go out of living memory. This will be a bit of a bittersweet year, I think.”