49 Years After D.B. Cooper Vanished Into Thin Air, A Scientist Uncovered A Compelling New Clue

This latest discovery comes from citizen sleuth Tom Kaye. The scientist is one of only a handful of regular people who’ve been permitted to see the case documents by the FBI. It’s just as well Kaye was granted access to the files, too: his work has unearthed a crucial new clue in what was presumed to be an unsolvable cold case. And with it, we’re now a whole lot closer to catching the crafty crook.

“Dan Cooper” – christened “D.B.” in the press – has been at large since November 24, 1971. At the time, there was nothing about the guy that singled him out as special or noteworthy. He simply walked up to the desk of Northwest Orient Airlines and purchased a ticket to Seattle, Washington. It’s a pretty low-excitement start to the country’s most daring heist.

The descriptions of D.B. Cooper weren’t very exciting, either. According to the FBI investigation, he was simply a middle-aged guy who was “nondescript” and “quiet.” Cooper was also dressed in a suit, white shirt and tie. So basically, he could’ve been just about any adult male boarding a flight in 1971… until he spoke to Flo Schaffner.

It happened a little after 3:00 p.m. Cooper had already enjoyed a smoke and a stiff drink – perhaps to calm any pre-hijack nerves. And when he slipped Schaffner the message, the flight attendant initially ignored it. She figured it was simply one more dude making a pass at her. Cooper demanded she look at it, though, and that’s when things took a turn for the worse.

Cooper told Schaffner to sit next to him and then issued his demands. He wanted $200,000 in cash plus four parachutes. He also asked for the plane to be refueled after they’d landed in Seattle. And if the hijacker didn’t get what he asked for? Well, then he’d blow up the craft. Faced with that terrifying threat, Schaffner had no choice but to be his messenger.

Flight 305 landed in Seattle a couple of hours after its scheduled arrival time. The FBI had Cooper’s money – and some snipers – ready and waiting. Cooper then traded the plane’s 36 passengers for his dough. But he didn’t wait around for the craft to finish refueling. Instead, he ordered the pilot to take off for Mexico City. Yet the daring hijacker never crossed the border.

In a staggering twist, Cooper leaped from the aircraft – according to the FBI – “somewhere between Seattle and Reno [in Nevada].” He was wearing a parachute and carrying the $200,000… and that was the last anybody ever saw him. Not for lack of trying, mind you. People have tried really hard to track down the mysterious hijacker – but they’ve been thwarted at every turn.

The day after the crime took place, the FBI poured into the area’s woods to look for any clue as to where Cooper could have gone. They found nothing. But the agents did put together a profile. They figured Cooper knew about aircraft and had knowledge of the region. The investigators also had a good idea of his character and appearance.

But it wasn’t enough. After five years of searching, the FBI had looked at and dismissed around 800 possible culprits. Only a handful were viable suspects, though, and no arrests were made. Yet there was one guy who continued to be singled out by those working on the case. This man’s name was Richard McCoy.

McCoy entered the picture several months on from the Cooper skyjacking. The reason? He had pulled off a heist in a very similar fashion to Cooper. Yep, parachutes, ransom money and all. This time, though, McCoy was captured shortly after his mid-air escape. Yet even though McCoy was convicted for his crime, the FBI eventually declared that he wasn’t the elusive D.B. Cooper.

Of course, the agents had to consider the possibility that Cooper had died during his escape attempt. This really was an incredibly risky skydive, after all. It was dark, Cooper’s parachute lacked any controls, and he was diving into territory filled with trees. All of this would have challenged a professional skydiver – and investigators didn’t think Cooper was one. But then came a breakthrough.

A boy named Brian Ingram was out with his parents in Vancouver, Washington, one day in 1980. He made a space for a fire close to the Columbia River – at Tena Bar – and came across a weird bump in the ground. “I wasn’t excited at all at first,” Ingram later told People magazine. “Then I brushed the sand off, and it was money!”

You guessed it: the stash was part of Cooper’s ransom money. The bills were damp and disintegrating – but their serial numbers proved they’d been among Cooper’s cash. This was a big deal, of course, and the FBI arrived soon after to hunt for further clues.

Unfortunately for the agents, though, they came up empty-handed. Yet the evidence still raised interesting questions. How did the $5,800 end up in this exact spot? And what did it mean for the hijacking case? Well, nobody ever offered any completely satisfying answers. But the money did provide investigators with three tantalizing theories.

The problem with the money was that it was found about 20 miles from where the FBI reckoned Cooper had landed. So if the investigators had their facts straight, how had the money traveled such a long way? One explanation was that the FBI was simply wrong about the landing site and the hijacker had in fact dropped down near the river. But not everyone was convinced.

Another theory suggested that the skyjacker – or perhaps some kind of accomplice – purposefully hid the cash there as a distraction. If that were the case, it certainly worked! Yet the most prominent explanation for the money ending up where it did came from Leonard Palmer, a Portland State University geologist. It’s called the “Washougal Washdown Theory.”

It’s got a catchy name, so you know it’s going to be good, right? Palmer’s suggestion is that Cooper did drop out of the plane around Ariel – as the FBI figured. But during the descent, Palmer said, some of his cash landed in a nearby stream. This money then followed the current and gradually made its way along the Columbia River to Tena Bar.

That’s all well and good… But it doesn’t tell us who D.B. Cooper was, does it? While the FBI continued to investigate the case, the experts never settled on a suspect – and the years continued to pass. The case grew cold. Then, in 2007, scientist Tom Kaye and his team got involved.

It was at this time that the FBI “reignited the case” of D.B. Cooper by asking the public for help. Kaye and his “Cooper Research Team” were then granted access to the case files and conducted several years of research. As we know, the work continues to this day – with Kaye’s latest discovery providing the most compelling clue yet.

The idea was to apply modern research techniques to a decades-old case. Kaye could take advantage of technology that didn’t even exist in 1971 to try to catch the criminal. And we should note that this most recent discovery is far from the first conclusion that the team has drawn.

You see, the team’s initial investigation focused on Cooper’s tie. The skyjacker had left it behind when he’d leaped from the plane. And one fact that Kaye uncovered, which he and his team published on CitizenSleuths.com, took “the number of potential suspects from millions down to hundreds.” What had he found? That Cooper had “worked at or had access to a plant that used titanium.”

Yet while this was clearly an exciting discovery, it didn’t result in the investigators finally getting their man. In 2016, in fact, the FBI officially closed the case, citing the need “to focus on other investigative priorities.” The door was still left open so that any new leads connected to the cash would be looked into, though. And Kaye’s recent discovery certainly is a striking piece of new evidence.

The discovery first came to the public’s attention in August 2020. Speaking to King 5, Kaye revealed that he’d taken a much closer look at the D.B. Cooper ransom money found in 1980. And using his trusty electron microscope, the scientist has seemingly made a big breakthrough in the case. So what’s the deal?

As we’ve already heard, the money has been the cause of much debate. Kaye’s team had even previously noted that the cash “continues to resist all natural explanations for how it arrived on Tena Bar.” But it seems that all the research so far had failed to consider the diatoms. And if you’re now wondering what we’re talking about, don’t worry: we’re going to explain.

Diatoms, it turns out, are algae. They’re pretty common, too. According to diatoms.org, these single-celled microalgae are actually responsible for about half of the oxygen we inhale. So perhaps that’s why Kaye and his team hadn’t paid much attention initially to the diatoms they’d found on the Cooper money more than a decade earlier. But then Kaye had an idea.

Kaye’s big moment came when he realized that the algae could reveal brand-new information. “We wondered if we could use these different species of diatoms that we found on the Cooper bills a long time ago to determine when the money got wet and when the money landed on [Tena Bar],” the scientist explained to King 5.

And that’s basically what Kaye did. He put the diatoms under the microscope and discovered that these little fellas only come out at a certain time of year. “[The diatoms] bloom in the spring. They do not bloom in November when Cooper jumped,” Kaye explained. This is an important find for several reasons.

For one thing, it throws a wrench into Palmer’s theory that the money floated into the Columbia River as Cooper parachuted toward the ground. Why? “The money was not floating in the water for a year, otherwise we would have seen diatoms from the full range of the year,” Kaye told King 5.

“We only saw [the diatoms] from the spring… the springtime bloom,” the scientist continued. “So this puts a very narrow range on when the money got wet and was subsequently buried on Tena Bar.” Okay, well, that puts an end to a 40-year-old theory. But what did happen?

According to Kaye’s research, Cooper’s cash could only have found its way into the water in either May or June. So this means that for at least five or six months after the dramatic hijack, the money was on dry land. But Kaye also reckons that it doesn’t indicate that the other popular theory is correct.

Remember when we mentioned earlier about Cooper or an accomplice burying the dough to throw off the investigators? At first glance, the new evidence could suggest that this is a workable theory. It’s certainly possible to say that the ransom money was buried for those elusive five or six months. Right?

Well, no. Kaye said that’s not the case. Presumably, this is because the scientist would’ve found evidence of a burial while investigating the diatoms. So that’s two workable theories thrown to the wind. All of which makes us return to the question of what actually happened on that day in 1971.

And even though Kaye’s discovery is significant, it probably doesn’t bring us much closer to solving the mystery. It just means that we now know how the money didn’t find its way to Tena Bar. But given that Kaye has been working on the case for so long, it’s probably okay to assume he has some sort of theory.

But you’d be wrong. Upon being pressed on the unresolved issues of the case, Kaye declared to King 5, “Cooper is still messing with us.” It’s probably not the answer that most people wanted, but it’s hard to argue with the man. Mind you, the case continues to generate interest – and another development cropped up in 2021.

This time it involves flight attendant Tina Mucklow. She was onboard Flight 305 and was an integral part of Cooper’s negotiations. Yet for all the years afterward, the flight attendant has refused to talk publicly about her experiences. And for some reporters and amateur detectives, this has made her the crucial link to solving the D.B. Cooper mystery.

So these folks must’ve been beside themselves with joy when, in January 2021, Rolling Stone released an interview with Mucklow. This is a woman who was up close and personal with D.B. Cooper, after all. Surely now they’d get the answers that they so desperately longed for?

Alas, while Mucklow no doubt had plenty of interesting things to say about the hijacking, none of them pointed the finger at a particular suspect. But perhaps the interview will help to get people off her back. “There have been many times when I’ve felt that people didn’t respect ‘no’ or ‘not interested,’” she explained.

And despite being accused by one Cooper obsessive of being a “wounded woman” who’s “traumatized” by the skyjacking, Mucklow has said that this simply isn’t true. “I went on with my life, pursued what I needed to do, had my own personal interests, likes and wants,” she told Rolling Stone. “I wasn’t defined by that hijacking.”

The FBI couldn’t find an answer to the D.B. Cooper mystery, then. And Tom Kaye couldn’t solve all of the case’s conundrums. Even flight attendant Tina Mucklow didn’t provide the insight so many people have been waiting for. So, will we ever find out who D.B. Cooper really is? We’ll just have to watch this space.

Thankfully, there are plenty of other juicy aviation mysteries to sink our teeth into while we wait. Take the disappearance of British South American Airways Flight CS59 in 1947, for example. The passenger plane was flying over the Andes towards its destination of Santiago, Chile, when its crew sent a baffling radio message. And those were the last words ever heard from Flight CS59.

Flight CS59’s international journey had actually started on July 29, 1947, when it had taken off from London, U.K. Yet it was a different plane that had made the transatlantic journey to the first stopping off point: Buenos Aires. An Avro York airliner with the name Star Mist had made that flight, you see. This was also a British South American Airways (BSAA) aircraft.

Once in Buenos Aires, though, the Avro Lancastrian called Star Dust took on the role of completing Flight CS59’s itinerary. The final leg involved crossing South America from Buenos Aires in the east to Santiago in the west. It also meant flying across the formidable Andes mountain range – the rocky spine that runs down the continent.

The flight plan for the journey in fact involved a route that flew over the Argentinean city of Mendoza in the eastern foothills of the Andes. The total flight time should have been three hours and 12 minutes. And the Avro Lancastrian should have flown the first 605-mile part of the journey at an altitude of 18,000 feet until it was over Mendoza.

After then passing over Mendoza, the pilot planned to take the airliner to a height of 26,000 feet to cross the high peaks of the Andes for the final 122 miles of the flight on to Santiago. So the Lancastrian duly took off from Buenos Aires at 1:46 p.m. And for most of the flight, everything seemed to be entirely routine.

But during the journey, as the plane passed over Mendoza, bad weather had closed in. And with it came high winds with speeds in excess of 100 mph – along with heavy snow. At 5:41 p.m., though, Star Dust was somewhere near Mount Tupungato, about 50 miles from Santiago. And it then sent a Morse code message from that location to Santiago.

The Star Dust crew’s message to Santiago stated that their estimated time of arrival was just four minutes away. It was a routine transmission but for two things. Firstly, the final word of the message was the incomprehensible word “STENDEC.” And secondly, it would be the last that was ever heard from BSAA Flight CS59.

Yes, the Avro Lancastrian, its five crew and six passengers had apparently disappeared into thin air over the Andes. But what had the enigmatic word, STENDEC, in the final message meant? Before we try to unravel that mystery, though, let’s take a look at other planes that have mysteriously vanished to see if they hold any answers.

And we actually don’t need to look far since British South American Airways seems to have been quite profligate when it came to losing planes in unexplained circumstances. Two other BSAA flights have disappeared over the years, in fact. On January 30, 1948, the year after Flight CS59 vanished over the Andes, another BSAA plane, Star Tiger, went missing over the Atlantic Ocean.

Star Tiger, an Avro Tudor IV passenger plane, had been flying from Santa Maria, one of the Azores islands in the North Atlantic, to the Caribbean island of Bermuda. Its journey had actually started from the Portuguese capital Lisbon on January 28. Its stop in Santa Maria had only been intended to be a brief one simply to re-fuel.

But the pilot, Captain Brian W. McMillan, changed his plans due to bad weather. So the 25 passengers and six crew spent the night in Santa Maria. Then, the next day, Star Tiger took off for Bermuda in the afternoon. Yet the subsequent high winds made Captain McMillan decide to fly at low altitude – 2,000 feet - in the hope of avoiding the worst gusts.

The severe winds knocked the plane off its course to Bermuda, though. McMillan therefore adjusted his flight path to take account of this. But after a final radio message at 3:17 a.m. on January 30, the plane was never heard from again. An official investigation into the incident concluded, “What happened in this case will never be known, and the fate of Star Tiger must remain an unsolved mystery.”

And it was just one year later that BSAA lost yet another plane. Star Ariel, an Avro Tudor Mark IVB airliner, was traveling from the island of Bermuda on January 17, 1949, bound for Kingston, Jamaica. The plane had departed in good, clear weather with 13 passengers and seven crew aboard.

The pilot, Captain John Clutha McPhee, also radioed Kingston about an hour after take-off – all was apparently well. Yet this was the last that was ever heard from Star Ariel. The official enquiry into this plane’s disappearance concluded that “through lack of evidence due to no wreckage having been found, the cause of the accident is unknown.”

Unsurprisingly, then, the loss of these two planes, Star Tiger and Star Ariel, in entirely mysterious circumstances helped to get the whole “Bermuda Triangle” mythology off the ground. But as Star Dust flew over the Andes in 1947, all of that was yet to come. And to find out more, let’s now meet the crew members.

The lead officer on Flight CS59 was Captain Reginald Cook. For his part, the pilot was an experienced flier who had seen action during the Second World War and won medals for his bravery. In fact, all of the flying crew – including First Officer Norman Cook and Second Officer Donald Checklin – had served with the Royal Air Force in WWII.

The other two crew members were Dennis Harmer, the radio operator, and flight attendant Iris Evans. During the war, Evans had served as a Chief Petty Officer with the Women’s Royal Naval Service. And Harmer had served as an RAF radio operator for three years. So this band of WWII veterans crewing the plane pretty much told the story of BSAA as an outfit.

You see, British South American Airways had been founded by demobbed WWII pilots keen to exploit what they saw as a gap in the market for air travel to the Caribbean and Latin America. The company’s inaugural flight in fact took off from London’s Heathrow Airport on New Year’s Day 1946, bound for South America. But the BSAA story predictably came to an end after the loss of that third plane in 1949. The BSAA badge was then subsumed into the British Overseas Airways Corporation.

As for the machine the crew was flying, that was an Avro 691 Lancastrian 3. The Lancastrian was in fact a modified version of the Lancaster – a four-engined WWII era bomber. These civilian airliners were used for passenger flights and for ferrying mail via both Canadian and British operators.

Star Dust’s first flight, fresh from the factory, came in November 1945, and BSAA took delivery of the aircraft in January 1946. That was a Lancastrian 3 variant, and 18 of this model rolled off the Avro production line. These planes could carry up to 13 passengers. And that brings us to the passengers on Flight CS59.

Marta Limpert was a German who lived in Chile, and accompanying her on the flight were the ashes of her late husband. Harald Pagh and Jack Gooderham were businessmen. Briton Paul Simpson worked as a civil servant and had diplomatic papers with him for delivery to the British Embassy in Santiago. In fact, some even theorized that Star Dust might have been sabotaged because of those papers. There was, however, no real evidence for this.

Also on the passenger list was Palestinian Casis Said Atalah, who was on his way back to Chile after a visit to his sick mother. And according to some sources, Atalah was carrying a diamond sewn into the fabric of his suit. Meanwhile, another travelling was Peter Young, who worked for Dunlop. As we know, then, this flight would be the last this disparate group would take.

So Star Dust took off from Buenos Aires at 1:46 p.m. for the 727-mile trip across the Andes to Santiago. Then at 5:41 p.m. radio operator Dennis Harmer sent a Morse code message to Santiago. In its entirety, the message read, “ETA [estimated time of arrival] Santiago 17.45 hrs STENDEC.”

The first part of Harmer’s message is clear enough. It is simply an announcement that the Star Dust was expected to arrive at the airport in Santiago four minutes after the Morse code transmission. But what on Earth did STENDEC mean? Well, that’s something that experts and amateurs have puzzled over for decades.

When the plane did not arrive at Santiago, then, search parties were sent out from both Argentina and Chile. BSAA pilots also scanned the terrain – but no wreckage and no survivors from Star Dust were found. So the only conclusion drawn was that the plane had crashed with the loss of all 11 people on board.

Yet the unanswered questions about what exactly had happened to Star Dust only served to make the elusive meaning of STENDEC seem all the more significant. And there is no shortage of theories as to what this perplexing word in that final Morse code message from Flight CS59 might possibly mean.

A Chilean Air Force operator had taken the last message from Star Dust, and he testified that the Morse code had been clearly transmitted. But he did say that the code had been tapped out very rapidly. Even so, STENDEC had puzzled the operator enough that he had asked Harmer to repeat his message. This he did, and the second time it came out just as clearly as the first, according to the Chilean.

Some thought that this strange word might have been something to do with a UFO. And some apparently thought the plane and crew might have been abducted by aliens. At the time, of course, UFOs and aliens were hot news, so any mystery was apt to be connected to extraterrestrial sources. But we’re probably safe to discount the involvement of little green men here. Although that brings us no closer to understanding the meaning, if any, of STENDEC.

More than 50 years later, then, the STENDEC mystery was still a live one. This was confirmed in 2000 when the BBC broadcast a program delving into the mysteries of Star Dust’s demise. The documentary paid particular attention to that final puzzling message too. Viewers then responded in their hundreds with possible explanations – and some were even quite plausible.

One said that Harmer might have been suffering from a lack of oxygen – impairing his Morse abilities. Perhaps he meant to tap out the word “descent”? That, after all, is actually an anagram of STENDEC. Alternatively, the enigmatic word might have been a series of letters standing for a full phrase. “Severe Turbulence Encountered, Now Descending Emergency Crash-landing” was mooted as one possibility.

But the idea that STENDEC was code for an emergency situation, or a panicked mistyping of descent, is flatly contradicted by the rest of the message, which is entirely routine. There was also the idea that the Chilean wireless operator might simply have got the message wrong – or that Harmer had made errors while sending it.

Remember, the Chilean operator had said that the Morse code had been tapped out very quickly. Ultimately, though, probably the most likely explanation is that it was a Morse code error in the sending or receiving. The dots and dashes for STENDEC are, after all, the same as for SCTI AR.

Of course, the spacings between dots and dashes is crucial for a message’s final meaning. And SCTI AR is not enigmatic; it’s simply standard code for “over,” which makes perfect sense in the context. The misunderstanding could have therefore occurred because the dot and dash spacings were incorrect. Tapping out very rapidly could easily have even led to a mistaken transmission or interpretation of the message.

And that’s probably as close as we’ll ever get to a definitive answer to the STENDEC message enigma. But that still leaves us with the missing plane, which had eluded the best efforts of searchers back in 1947. That situation – the apparent complete disappearance of an airliner and its passengers – would in fact continue for half a century.

A significant breakthrough came in 1998, though, when two Argentinean climbers were scaling Mount Tupungato. They were actually on the Tupungato Glacier at an altitude of 15,000 feet when they came across the remains of a Rolls-Royce Merlin engine and some other debris. And the Star Dust had been fitted with four Merlin aviation engines.

Then a couple of years later, Argentinean soldiers set out to search for wreckage on the Tupungato Glacier. Their finds included a wheel with its tire still inflated and one of the four propellers. Much more gruesomely, the soldiers also found a variety of body parts. The human remains included three torsos, a foot still in its boot and a hand.

Thanks to the freezing conditions and the dry winds, the hand and other body parts found were well preserved. In fact, the hand still retained its manicure and was clearly that of a female. And the only female aboard Star Dust had been Iris Evans, who was just 26 when she died in the crash. The discovery of the remains then triggered a search for surviving relatives so that identities could be confirmed via DNA testing.

The search for descendants and surviving relatives took two years – but brought some success in 2002. In fact, DNA testing confirmed the identities of five of the eight British crew and passengers on the flight. This conclusively confirmed that the bodies were of some of those aboard the plane when it had crashed and that the wreckage was from Star Dust.

Margaret Coalwood of Nottingham, U.K., was one of the surviving relatives who was tracked down. Second Officer Donald Checklin was her cousin. Coalwood spoke to The Guardian in 2002 after DNA testing had confirmed the identity of her cousin’s body. She said, “He was my older cousin, who I idolized hopelessly. He flew Lancaster bombers and got medals for bringing back his aircraft one time on a wing and a prayer.”

But now that the crashed plane’s wreckage had been found, the question was what had caused the disaster? Well, it seems that high winds from the jet stream may have pushed the flight off course. Misjudging his position, the pilot might then have started his descent too soon, putting him on a collision course for Mount Tupungato. Alternatively, high winds and icing may have plunged the plane into the mountain side. Whatever caused the crash, though, it’s likely that more wreckage from Star Dust and further passenger remains will emerge from the glacier as the years go by.