I have friends who live on the Isle of Mull (Scottish Hebrides) and I’ve spent a number of glorious holidays there visiting them. As a result, I was immediately intrigued when I discovered that there was a forty-year-old unsolved aviation mystery at Glenforsa Airfield (which I’ve previously written about here).

The facts of the case, such as they are known, are as follows:

G-AVTN was a Cessna F150H, a high-wing single engine aircraft which was kept at Oban on the mainland. The aircraft was on loan to the pilot, who was a 55-year-old London businessman. He flew to Glenforsa on Mull with his girlfriend and used the island as a base for exploring the other islands, apparently looking for opportunities for investment.

On the 24th of December 1975, the couple flew from Mull to the Isle of Sky and spent the day there, returning to the Glenforsa Hotel just in time for dinner.

Apparently after the meal, the pilot made the comment that he thought it would be possible to make night landings at Glenforsa. This isn’t quite as random as it sounds; if the airfield could take night flights that could increase the opportunities for travel, which would be beneficial for the hotel and other investments in the area.

But as I said, I know the island fairly well and although it has a perfectly pleasant airfield, the idea of a night landing there is, well, hard to fathom. Glenforsa is a quiet little grass strip, 780 metres (2,500 feet). We had to ring in advance to make sure the sheep were out of the way.

So on Christmas Even in 1975, the pilot announced that he was going to prove that he could do a night circuit and land it in the dark. It was a moonless night. The owner of the hotel said later that he tried to stop him. The pilot’s response, he said, was terse. “I am not asking permission, I just thought it was courtesy to let you know.”

The pilot and his companion took two torches (flashlights) to use as make-shift landing lights; she agreed to stay on the ground and use them to guide him in. Other guests at the hotel stepped out to watch and some claimed to see two sets of lights moving independently, suggesting there was someone else out there. However, the pilot’s companion was clear: she was the only one on the runway and there were no other lights other than the Cessna. The pilot taxied to the far end of the runway, stopped for a few minutes with the engine running, and then took off into the darkness. The guests watched the aircraft turn out over the Sound of Mull and then disappear from view. A pilot watching from the hotel said it was a perfect take-off. They retreated back to the warmth of the hotel.

A half an hour later, his companion returned, alone. She had not seen or heard any sign of the aircraft. The weather had turned bad: rain and sleet battered the runway. When there was still no sign of the pilot and his aircraft, they contacted the police. Volunteers and the police searched the expected flight path as far as they could that night but found no wreckage. They searched again at daybreak, hoping to find some sign of the pilot or the aircraft. Hundreds of volunteers combed the countryside and fishermen with boats searched the water for debris. The RAF and the Naval Air Service joined the search using helicopters and sonar equipment, however no trace of the wreckage was found. The pilot and the Cessna 150 had disappeared without a trace.

It was four months later when the pilot’s body was discovered, lying on a hill near the hotel and the airfield.

The discovery brought up more questions than it answered. The body was in plain sight, so it made no sense that it hadn’t been discovered as a part of the massive search effort, in which hundreds of volunteers searched the small island. Also, forensic testing showed that he had no injuries at all other than a scraped leg: the cause of death was exposure. They also found no sign of drugs or alcohol, although witnesses said they saw him drinking at the hotel. And then there was the bigger question: where was the plane?

Another decade passed before anyone reported any trace of the Cessna 150. A pair of clam divers discovered the wreckage of a red-and-white aircraft in 100 feet of water, about a mile to east of the direct approach to the runway. They took photographs which showed the aircraft in pieces: the engine was lying some distance away, one of the wheels was torn off , the front perspex windscreen was shattered and they said that both wings were missing. The clam divers said that the aircraft’s registration was G-AVTN. A local report from the time said that the doors were locked. Inside the cockpit, they said, was only a large lobster.

Now, it wouldn’t be surprising if the pilot lost sight of the airfield and flew into the sea. Taking off in the dark on a whim, after a pleasant evening in the Hotel Glensforsa, it would have been more surprising if he hadn’t crashed. But none of this explains how the pilot and his aircraft became separated.

Locals wondered if he managed to escape the aircraft before it crashed into the sea. I think this is highly unlikely. That would be pretty difficult to do in a Cessna at the best of times, let alone while the aircraft is crashing. If he could get the Cessna stable enough that he could climb out of it, he would have no need to jump. I can’t think of a way to accidentally fall out of a moving 150 unless one were wing-walking, perhaps. But even if you doubt me, there’s the fact that he had no injuries consistent with falling a few hundred feet and smacking into a hill.

He could have crawled out of the wreckage after the crash. The red-and-white aircraft was found close enough to the coast that he could have swum to shore. From there, he needed to clamber up a steep cliff wall, cross a road and then hike up the hill. The lack of injuries seems suspicious after such a violent impact, but not completely impossible. The windscreen was reported as shattered, which could have given him an escape route. The forensic tests didn’t show any sign of salt water or marine life on the corpse, but they admitted that after four months of being exposed to the weather on the hill, the evidence could have been washed away.

The odd thing here though, is that to get to the hill where his body was found, he needed to cross the road which led to the Glenforsa Hotel. Even if he wasn’t sure where the road went, surely it would make more sense to follow it than to climb up the hill?

In 2004, three Royal Navy minesweepers discovered an aircraft in the same underwater area. They thought it might be G-AVTN and tried to get underwater video of the wreckage. The visibility was too poor and they failed; however, the divers reported that they could clearly see that one of the wings was still attached. The weather held them back from further exploration but it brings up another possibility: the aircraft that the clam divers saw in the water was not the Cessna 150 at all. There is at least one other red-and-white aircraft known to have crashed into the sea in that area, so although the divers said they checked the registration, they may have simply been overcome with the excitement of their apparent find.

The weather stopped the Royal Navy from further exploration and so now we just don’t know: is G-AVTN submerged in the waters there or not?

If we consider that G-AVTN has not been found, then there’s another possibility. The pilot was never involved with a plane crash but instead his body was was dumped on the hillside by an unknown third-party. This could explain why the pilot was insistent on going out in the dark (to meet someone?) and why some of the guests at the hotel believed they saw more lights. It would certainly explain how the body was missed in the initial search. In this scenario, it could be that he never left Glenforsa but was overwhelmed still on the ground, or that he landed at another airfield: this would be no odder than his apparent sudden decision to go night flying just to prove that it could be done. In either instance, whoever overwhelmed the pilot could have flown the aircraft away, to be abandoned elsewhere.

None of these theories is particularly satisfying but they are likely to be all we will get unless someone decides to fund the recovery of the aircraft wreckage. At least it makes for a fascinating conversation when warm and dry in a cozy island pub.