The hills, moors and glens around Muirshiel Country Park above Lochwinnoch, serene and majestic. spirit of solitude transcends the ages. In summer, colourful blossoms like purple heather, golden bog asphodel and blue butterwort mantle mosses and morasses like magic carpets. Wistfulof curlews, golden plover and skylarks transform the rugged domain into an earthly paradise.

But the remote realm has a more sinister side, especially in winter. It's known as Renfrewshire's Bermuda Triangle because so many horrific aircraft crashes occurred there.

Sadly, the young lives of many brave aircrew ended in that lonely landscape. Wreckage from aerial tragedies is still visible on windswept hills. Debris lies like moorland memorials to heroes.

During my time as a countryside ranger at Muirshiel Country Park, I researched the history of these plane crashes. One of my main sources was the late Quintin McKellar who farmed at Heathfield and East Tandlemuir (later Conveth) for many years. He knew the hills around Muirshiel better than anyone else and was the person to go to for advice.

One misty morning April 1988, senior ranger Eric Harley, ranger Iain Brotherton and I discovered grey, metal fragments of a crashed aircraft among heather near the site of the drained Calder Dam just off the barytes mines track. We knew it was from a Swordfish plane.

Mr McKellar told us what happened. It was a pitch-black January night in 1942 at the height of the Second World War. Mr McKellar's father, Archibald, who farmed the land around Heathfield before him, was out on the hills rescuing sheep trapped in deep snowdrifts. Suddenly, he heard the terrifying drone of an aircraft coming towards him. Archibald was close to the summit of Windy Hill, more than 1000 feet above sea level. So he threw himself on the ground as the plane roared overhead. He was unaware that the aircraft – a Swordfish – had crashed less than a mile away near the Calder Dam.

Because of news blackouts during the war, no announcements of military manoeuvres were broadcast so he had no reason to believe anything sinister had happened. Archibald just put it down to a nasty experience with a low-flying aircraft.

It was three weeks before the awful truth became known. Bob Fleming, the McKellar family's shepherd, was out in the snowy landscape searching for sheep when he came across a horrific spectacle.

The aircraft lay mangled and mutilated on the moor. Inside were the frozen-stiff bodies of two dead crew members. Even more macabre was the gruesome spectacle of a third man hanging from the cockpit, trapped and dangling by his feet.

The McKellar family volunteered to help teams from the Royal Air Force and local police to remove the bodies. Their unique knowledge of the hills and moors made them the right people for the grim task.

Although still a teenager at the time, Quintin bravely made his way across the snowbound moor with a pony and sledge to retrieve the corpses and take them back to a makeshift mortuary in an out-building at Heathfield Farm. It was something he remembered for the rest of his life.

It later transpired that the Swordfish was one of four which crashed that night on a flight from Fraserburgh in the north of Scotland to Macrihanish on the Mull of Kintyre. The other three impacted a few miles farther north at Alexandria, near Loch Lomond. The official explanation was they all ran out of fuel in bad weather.

The Swordfish which landed on the moors around Muirshiel with such disastrous consequences was quickly removed from the crash scene. Only one wing fragment remained – and that was the piece which Eric, Iain and I discovered 46 years later.

There were many more aircraft crashes in the neighbourhood – inspiring the legend that the Muirshiel neighbourhood was Renfrewshire's Bermuda Triangle. The belief was instigated by similar inexplicable tragedies off the coast of Bermuda island in the Atlantic Ocean.

One explanation for the carnage at Muirshiel is that vast amounts of minerals in the ground interfered adversely with navigational equipment. Another is that hastily-mobilised aircrews were insufficiently trained to handle such powerful planes.

On a more sinister level, it was rumoured that dark cosmic forces were at work which affected the judgement of doomed pilots, navigators and crews.

It's speculated that these cosmic forces included air ions, electro-magnetic waves, atmospheric electrical fields, thermal radiation and sudden weather changes causing physical and psychological malfunctioning of the crew's human neuro-muscular and cardio-vascular systems.

Whatever the explanation, there is one thing I shall always remember from my time as a ranger at Muirshiel Country Park.

And that was cycling home from work past the ruins of Heathfield Farm on dark winter nights when there wasn't a moon or star in the blackened skies – then looking at the forbidding building which was the moorland mortuary for the tragic team on the Swordfish aircraft.

Derek Parker worked as a countryside ranger at Clyde Muirshiel Regional Park from 1985 to 1999.