It's been nearly 50 years since an American fighter jet went down off Britain's coast, spawning a conspiracy theory that persists until this day.
However reports of bizarre sightings in the sky fuelled intrigue and mystery - and speculation that fighter jet XS894 was downed by UFOs.
There were claims of flying transparent spheres and unusual blips on the radar, the Grimsby Telegraph reports.
And the pilot's body was missing when the aircraft was discovered on the seabed weeks later with its canopy closed, only adding to the mystery.
A Grimsby Evening Telegraph report on the plane crash
Captain Schaffner's has never been found, but he was declared dead.
Based at RAF Binbrook, Lincolnshire, during the Cold War, the 28-year-old pilot took off into the skies over Grimsby on the night of September 8, 1970, and headed out over the North Sea en route to Flamborough.
But the plane ditched into the sea five miles south of Flamborough Head shortly after 10.30pm, sparking an air and sea search and rescue operation that was covered by local newspapers.
On October 7, 1970, it was revealed that the plane had been found when Royal Navy divers sailed to Flamborough onboard the HMS Kedleston, but their search still did not provide answers and they returned empty handed.
The pilot's body was still missing and the plane remained on the sea bed.
It would take until December that year for the submerged plane to be brought to the surface, but to everyone's surprise the canopy over the cockpit was closed and the cockpit was empty.
The crash has sparked conspiracy theories over the years
The American pilot was still missing and immediately rumours began to circulate.
In October 1992, the story resurfaced and the Grimsby Telegraph began publishing a series of articles written by Pat Otter, with the incident being described as The Riddle of Foxtrot 94.
Mr Otter claimed that new evidence had surfaced and the real reason behind the downing and disappearance of the pilot had a cause which was out of this world.
Mr Otter claimed the new evidence pointed to the involvement of UFOs over the region.
He cited unnamed military sources, claiming they had seen unidentified objects across Grimsby, Cleethorpes, Scunthorpe, Hull, the Humber, all the way up the coast to Flamborough and beyond.
Captain Schaffner during this period was on Quick Reaction Alert duty and was dispatched to investigate the blips on radar.
One newspaper report stated the pilot had reported seeing a flying cone and a transparent sphere that flew around his Lightning aircraft, causing his equipment to malfunction.
There were claims UFOs had surrounded a fleet of Phantom jets
It went on to claim the UFO flew much faster and out manoeuvred his plane.
The American Air Force, stationed in Britain at the height of the Cold War, ordered their nuclear planes to take off and join the search.
Further newspaper reports stated that all investigations had reached a brick wall. It alleged the real reason behind the crash was being covered up in a whitewash.
The story dropped off the radar, albeit for a few reports made by UFO investigators, such as Tony Dodd, who wrote about the incident in one of his books, and Bruce Barrymore Halpenny, who reported the incident in one of his Ghost Stations books.
Then in July 1994, the Grimsby Telegraph featured an article about the mass of alleged UFO sightings which had taken place over the region in 1970.
It claimed that UFOs had been sighted over Grimsby, especially over the docks, up the Humber, over Scunthorpe, Lincolnshire, across at Hull, and up the coast.
One of the sightings took place over Cleethorpes Pier, and it is claimed that a top secret Anglo-American operation - Operation Aeneid - was launched in an attempt to track, photograph, and ascertain what had happened.
Newspaper reports about the incident in 1970
Throughout August 1994, numerous articles appeared in the Grimsby Telegraph about these sightings, with headlines claiming radar operators had been called in to view the craft.
There were reports the unidentified craft had surrounded a fleet of Phantom jets and that a cat and mouse chase resulted in the death of Captain Schaffner.
It became a big story and was covered in a series of double page spreads in the Hull Daily Mail.
A transcript was published to reveal what was said between the control rooms and the Lightning aircraft piloted by Schaffner.
Nick Pope, former Ministry of Defence employee on Sec(As)2A desk, which dealt with UFO sightings, wrote about it in one of his books.
Other eyewitnesses told their stories, including a team at RAF Binbrook who said it was their job to investigate the crash but claimed they were stalled and that various instruments had vanished.
One of two audio transcriptions taken from that night revealed the pilot had described these strange craft.
It seemed like the case would remain a mystery but several things happened that would change the course of the story.
In 2002, Captain William Schaffner's sons, Mike and Glenn, launched an attempt to see the official files.
Eventually the files were declassified and they showed that the incident was an unfortunate accident with a plausible explanation, even going so far as to suggest that the cockpit canopy was closed because the hydraulic fluid compresses when it gets cold, as it would on the floor of the North Sea.
Another breakthrough in the case followed in recent years when the National Archives declassified hundreds of files containing thousands of pages.
Across these are a number of interesting files, including Defe-24-2039-1-1 and Defe-24-2027-1-1, both of which contain numerous pages on the incident.
These files, whilst held in the National Archives' UFO files, appear to show that the incident was a tragic accident which claimed the life of Captain Schaffner.
Still, the mystery continues to attract attention, theories, and counter theories.