MOTORING up the steep, narrow hill that leads to Lieutenant-Commander John Moffat's Perthshire home, we are confronted by a four-wheel drive. "He can reverse his dratted Chelsea tractor, because I'm sure as hell not going to move my car," says the former navy pilot, jaw jutting determinedly as he faces down the other driver.
Sure enough, the vehicle is put into reverse and we drive on, with Moffat chuckling merrily behind the wheel like a mischievous schoolboy as we pull into the drive of his Dunkeld bungalow.
Clearly, he has lost none of the bulldog spirit that saw him survive the Second World War when, as a heroic young sub-lieutentant in the Fleet Air Arm, he courageously fought in one of the most decisive naval battles of that bitter conflict.
Indeed, admits Moffat, who will be 90 on 22 June – an event due to be celebrated with a knees-up – he's famously thrawn.
When he tells of the part he played in sinking the Bismarck, the German warship that went down 68 years ago this week, he admits that he doesn't know how he managed to keep flying against the hammer blows of the north Atlantic winds as he battled his plane through an atrocious gale, convinced that every gun on the most powerful battleship in the world was aimed directly at him and his crew.
Rapid gunfire was coming towards Moffat's Swordfish – the now legendary British torpedo bomber – like hail. The biplane had an open cockpit, leaving crews unbelievably vulnerable. Almost 70 years on, Moffat can still feel the whip of the wind on his face, smell the cordite that filled his nostrils and hear the crack of exploding shells.
"I do not know how I managed to keep flying: every instinct was screaming at me to duck, turn away – an impulse that was hard to fight off. But I held on," recalls Moffat, a proud Borderer who grew up in Kelso, enlisting in the Fleet Air Arm in 1938 after clerking, in misery, for a local bus company.
He certainly did hold on: it's since emerged that the records suggest Moffat dropped the torpedo that hit the powerful battleship's stern, jamming her rudder and preventing her from outrunning her Royal Navy pursuers, a thrilling story he tells in his newly-published memoirs, I Sank the Bismarck.
"There's rarely been a day when I have not remembered what it was like to fly towards that great monster of a ship, or what I saw the next morning when she toppled over into the sea," he says quietly, adding that the image of those poor German sailors struggling in the freezing, oily water enters his mind daily. "And I do not expect to see a day when it does not."
A lifetime has elapsed since those dark days. He has known great happiness in his family life since he went on to marry Marjorie, from Shilford, with whom he'd fallen in love the moment he saw her.
They had two daughters, Pat, 61, and Jan, 57, and a fleet of grandchildren and great-grandchildren. Sadly, Marjorie died in 2001 after 58 "blissfully happy" years of marriage.
After the war, Moffat had a successful career in hotel management, before opening an antiques shop in Aberfeldy on his retiral. He has a fund of stories in his memory banks. During the Battle of Britain he was in 758 squadron, aka "the broken-down actor and windy jockey squadron", he chortles. "We had Ralph Richardson and Laurence Olivier as members. If it hadn't been for the constant air raids it would have been great fun.
"We didn't see much of Olivier: Vivien Leigh was on the scene! Ralph Richardson, though, was an instructor. He told me, 'If you see an airplane flying over the airfield like this,' and he mimicked a plane rising and falling with his hands, 'then it's me. I suffer from kangaroo petrol'. What a character!"
But he has never forgotten the sinking of the Bismarck and the waste of so many young lives. When a young American researcher, Mark Horan, using action reports written at the time, concluded that out of the two pilots who could possibly claim to have dropped the torpedo that hit Bismarck's stern, Moffat was the most probable candidate, it gave him no personal pleasure.
"Whether or not it was my torpedo that hit the warship and made her uncontrollable does not really matter to me. What matters is that I along with the rest of my colleagues did it."
Remember, he urges, he saw the terrible results. No matter how pleased he was to remove a threat to Britain and its convoys, he cannot take any satisfaction from the deaths of nearly 2,000 men. "We were at war, we did our job, but I never claimed any result from my attack.
What he can say is that the 43 crew members of the 15 Swordfish that attacked the Bismarck did what was demanded of them.
Today, Moffat is the only survivor of that brave band of men who sank the Bismarck. His face fills with sadness when he recites their names. "Anyone who saw us afterwards would know what that effort cost us. If we hadn't decided that we could fly in such appalling conditions, if we hadn't pressed on against the gunfire, if we had failed, then the Bismarck would have escaped to safety," he insists.
After the war there was a famous feature film, Sink the Bismarck!, starring Kenneth More – of which Moffat does not think much – as well as several books and numerous articles. However, he believes that many of them seemed to downplay the importance of the Fleet Air Arm and their 15 Swordfish.
In 1989, the man who found the wreck of the Titanic, Bob Ballard, discovered the wreck of the Bismarck, starting a fresh wave of interest. A number of TV documentaries have been made since, some arguing that the Bismarck was not sunk but scuttled by her own crew. Such claims, Moffat says angrily, write the whole of the Royal Navy out of the picture.
Then, in 2004, the wreck of the Ark Royal, on which Moffat was based, was discovered. For the documentary film-maker Mike Rossiter, with whom he's collaborated on his memoirs, Moffat manoeuvred a remote underwater camera from a large yacht as though he were landing on the deck of the carrier, now lying 3,000 feet below the surface of the Mediterranean.
From the same yacht he saw the wreckage of one of his beloved Swordfish that he thinks fell from the Ark Royal, when it was torpedoed six months after attacking Bismarck.
Yes, it all happened a long time ago, sighs Moffat, but he believes that knowledge of the events should be kept alive – "if only to prevent anything like that happening again".
He has never lost his love of flying and sold his share in a Piper aircraft only nine months ago. "I'm still very fit," he says, adding that he swims twice a week and was still hunting until a few years ago. His horse, he laughs, was called Galloping Grandad.
On 8 May Moffat was a guest of honour at St Paul's Cathedral in London, at a service to celebrate the centenary of naval aviation.
"As Prince Charles arrived with Camilla, he winked at me," Moffat confides. "The young Royal Marine who was my 'minder' for the day couldn't believe his eyes. The Prince, who I've met several times, said, 'John, what did you think of the service?' I told him. 'Not much, sir, especially the choir. But then I'm an Episcopalian'. Prince Charles had a good laugh, because he has a great sense of humour."
Before I leave, Moffat shows me treasured photographs of his family and his late wife. "She was the most important influence on my life – and I've had a great life. Marrying her was the best day's work I ever did," he says, adding that Marjorie always hated flying.
He produces a picture of them both in a light aircraft at Oban. "That's the only time she ever let me fly her anywhere. Afterwards, I asked her if she'd enjoyed it. She said, 'I'll tell you one thing, you fly a plane a bloody sight better than you drive a car'."
Giggling at the memory, he drives me back to Dunkeld station. He looks up at the sunny blue sky and declares the weather is set fair for his next adventure. He's flying tonight, piloting a friend's Cessna plane over Perthshire, still reaching for the sky.
• I Sank the Bismarck, by John Moffat (Bantam Press, 16.99).