This story is a collaboration with Biography.com.

You wouldn’t jump out of an airplane wearing a tie. So, naturally, the most famous skyjacker to never be found, the dapper D.B. Cooper, took his tie off on Thanksgiving Eve, 1971, just before dropping out of a Northwest Orient Airlines plane somewhere over the Pacific Northwest.

That discard tie remains one of the Cooper case’s strangest—and most tantalizing—physical objects. It’s also become a magnet for competing theories, because tiny debris trapped in the tie’s fabric may shed light on the skyjacker’s professional life before he vanished into the night.

For years, Eric Ulis—the amateur sleuth who has made it his mission to solve the enduring D.B. Cooper mystery—has argued that the infamous tie yields enough clues to finally reveal Cooper’s true identity.

The theory hasn’t produced a public match. But the evidence hasn’t gone away, either.

In 2024, Ulish argued that a newly emphasized particle on the tie—described in prior reporting as part stainless steel, part titanium—backed up his belief that Cooper may have had ties to a Pennsylvania company, Crucible Steel, that built parts for Boeing in the 1960s. Ulis also pushed for new testing of the tie, including possible DNA analysis, to no avail.

Ulis has been fighting to free D.B. Cooper’s tie from FBI holds, even suing the government for access, saying that the 100,000 particles left behind on the clip-on fashion accessory can tell the definitive story about just who the tie belonged to, and where it traveled. But a federal court dismissed Ulis’s FOIA request, saying the law compels access to records, not tangible evidence like a necktie.

While the most promising legal path to get the tie into Ulis’s hands and unlock new testing hit a dead end, the tie remains central to the case. Later coverage of newly released FBI records reported that the tie contained more than 100,000 microscopic particles, including unusual materials such as unalloyed titanium, bismuth, and strontium sulfide, which lends credence to the idea that the tie may preserve traces of a specialized manufacturing environment.

The tie itself was ordinary—a $1.49 tie, purchased from JCPenney around Christmas 1964, and found on seat 18-E of the fateful airliner—but the debris wasn’t. Ulis has pointed to that steel-titanium particle as a clue that may connect to a specialized metalworking environment.

Ulis tracked that smidge of detail from a decade-old scientific report on the Cooper case and used U.S. patent information to trace various particle fragments from the tie to Crucible Steel of Pennsylvania. “Headquartered in the suburbs of Pittsburgh, a significant subcontractor all throughout the 1960s, it supplied the lion’s share of titanium and stainless steel for Boeing’s aircraft,” Ulis said of the metal-fabric shop.

Experts believe that anyone skyjacking the plane the way D.B. Cooper did must have possessed insider knowledge of the Boeing 727 and of the Pacific Northwest. Crucible Steel workers regularly made the trip from Pennsylvania to Boeing’s headquarters in Seattle. This doesn’t prove Cooper worked for Boeing, Crucible, or any contractor. But it helps explain why the tie has drawn so much attention.

Ulis tracked the now-defunct company’s assets over the decades and picked through historical records to land on a specific person of interest: a man named Vincent Carl Petersen, a Pittsburgh-area titanium research engineer who was also in Seattle around the time of the skyjacking.

“This is also the time, 1971, when Boeing had this significant downturn,” Ulis said at the time. “It’s reasonable to deduce that D.B. Cooper may well have been part of that downturn.”

But Ulis later broadened his own suspect framing. In an open letter to then-FBI Director Christopher Wray, he wrote that his Crucible Steel research had narrowed his attention to two men: Petersen and John Philson Strand. Ulis also wrote that he did not know whether either man was Cooper. (In 2024, Ulis announced that he was working with the family of Petersen, who died in 2022, in an effort to press the FBI for DNA testing of the tie.)

The tie isn’t the only piece of evidence that has led to new developments in the Cooper case. In late 2024, YouTuber Dan Gryder and the children of Richard Floyd McCoy II, a long-debated Cooper suspect whom the FBI has publicly said it ruled out, claimed they turned over a parachute, harness, and logbook to the FBI. But as of May 2026, the FBI has not publicly reversed its standing position on McCoy.

Clearly, when it comes to unsolved mysteries, few continue to simmer quite like the D.B. Cooper case, the only unsolved commercial airline hijacking in history. The unknown skyjacker—he called himself Dan Cooper, but the media misreported the name as D.B. Cooper, which stuck— paid $18.52 cash for a one-way ticket to Portland and boarded Northwest Orient Flight 305 on November 24, 1971, boarding the flight without offering up identification due to a lack of regulations at the time.

Along with a strong knowledge of airplanes and parachutes, law enforcement officials believe D.B. Cooper had a solid connection to the Pacific Northwest based on comments he made during the flight about the terrain below.

Carrying with him a briefcase and paper sack, Cooper passed a note to a flight attendant seated behind him halfway through the flight and whispered that she better look at the note since he had a bomb. Cooper opened his briefcase to reveal what appeared to be a bomb and then relayed his demands of $200,000, multiple parachutes, and a refueling truck on the ready in Seattle so he could take off again, bound for Mexico City.

The demands were met, and the planned 30-minute flight turned into two hours of circling the Puget Sound as crews readied on the ground. The airliner’s 35 passengers were released, along with some of the crew, and Cooper negotiated the specifics of the flight path and plane setup—he required a set speed, flap angle, and plenty more—before he took off again with four crew on board.

Somewhere still over Washington, Cooper then opened the rear staircase and parachuted from the plane, but the exact location and timing is unknown. Immediate searches yielded no evidence, and over the years, experts have been unable to determine an exact search area due to the multiple variables involved in the night jump.

In 1978, a hunter found a placard with instructions for lowering the aft stairs of a Boeing 727. Then, in 1980, an 8-year-old vacationing along the Columbia River near Vancouver, Washington, found three packets of the ransom money in the sand along the river’s edge.

The FBI still has that necktie, though, so the quest for D.B. Cooper answers continues to raise new questions.