背景介绍：1971年的美国正处于民航劫机高发期，安保体系极度松散——登机无需安检、身份核查流于形式，航空公司为保障人质安全，常对劫机者的要求妥协。

同时，波音727客机的设计缺陷为逃脱提供了可能：机身后部设有可手动操控的舷梯，低空低速飞行时仍能正常开启。而D.B. Cooper选择在感恩节次日作案，彼时航空客流密集，地面核查注意力分散，进一步为其劫机与跳伞逃脱创造了客观条件。

故事简介：1971 年 ，一名自称丹・库珀的男子登上美国国内航班，以炸弹威胁勒索 20 万美元与 4 个降落伞。飞机降落后他释放乘客，要求机组飞往墨西哥城，随后在太平洋西北上空从机尾跳伞，从此人间蒸发。

FBI 调查数十年无果，仅多年后在河边找到部分赎金。库珀的身份、生死及巨款去向成谜，此案成为美国近代最著名的悬案之一，也让他成为传奇符号。

On a cold evening in November 1971, a man stepped onto a plane in the north-west of the United States and quietly made history. He did not shout, threaten anyone loudly, or cause panic among the passengers. In fact, most people on the plane never realised anything unusual was happening at all. Yet by the end of the night, this man would disappear without a trace and become the centre of one of the most famous unsolved mysteries of the modern age.

His name, according to his ticket, was Dan Cooper. But history would remember him as D. B. Cooper.

The story begins on November 24th, 1971, the day before Thanksgiving. Cooper boarded a short domestic flight from Portland, Oregon, to Seattle, Washington. The flight was expected to last less than one hour. Cooper appeared calm and well dressed. He wore a dark business suit, a white shirt, a black tie, and sunglasses. Witnesses later described him as polite, quiet, and middle-aged, with no strong accent.

After sitting down, Cooper ordered a drink—bourbon and soda—and waited. A few minutes later, he handed a small note to a flight attendant named Florence Schaffner. The note was typed, which reduced the number of clues investigators could later use. At first, she did not read it. During that time, flight attendants often received phone numbers from passengers, and she assumed this was the same. But Cooper leaned towards her and spoke softly. He told her that she should read the note because he had a bomb.

He briefly opened his briefcase to show her what appeared to be red cylinders connected to wires. The note itself was clear and direct. Cooper explained that he had explosives. He demanded 200,000 dollars in cash, four parachutes, and a fuel truck ready when the plane landed in Seattle. If his demands were not met, he warned, he would use the bomb. Importantly, he later asked for the note back, showing careful forethought.

Schaffner immediately took the note to the cockpit and informed the pilot. The pilot then contacted the airline and the authorities. What followed was a quiet and careful negotiation. The airline agreed to Cooper’s demands, and the plane continued flying to Seattle as planned. During this time, Cooper remained calm. He drank his bourbon, smoked cigarettes, and spoke politely to the crew. He did not show anger or fear.

When the plane landed in Seattle, it stopped on the runway and waited. The money arrived in a bag, along with four parachutes—a mix of civilian and military models. Cooper checked everything carefully. He rejected one military parachute, commenting that its D-ring release mechanism looked unsafe. Some investigators later suggested that this detail pointed to possible parachuting experience, although others disagreed with this interpretation.

Once he was satisfied, Cooper allowed all the passengers to leave the plane. Only the pilot, co-pilot, flight engineer, and one flight attendant remained on board.

At this point, Cooper gave new instructions. He ordered the plane to take off again, heading towards Mexico City. He requested a low flyingaltitude and a slow speed. These instructions surprised the crew, but they followed them. Cooper also insisted that the rear stairs of the aircraft remain usable during flight—something unusual, but possible on this type of plane.

Some time after take-off, as the aircraft flew over the dark forests of the Pacific Northwest, with poor weather conditions reported in the area, Cooper made his final move. He told the flight attendant to join the pilots in the cockpit and close the door. Alone in the back of the plane, Cooper put on the civilian parachute he had chosen, tied the bag of money around himself, and prepared to jump. Before doing so, he removed his black clip-on tie.

At around 8 p.m., somewhere over Washington state, Cooper opened the rear stairs and jumped out of the plane into the night. The crew later felt a change in air pressure and noticed a warning light. When they cautiously left the cockpit about twenty minutes later, Cooper was gone. All that remained was his tie, two parachutes, and parts of the briefcase contents. What appeared to be a bomb was later widely believed to have been fake.

That was the last confirmed moment of his life.

Almost immediately, the question arose: could he have survived? The conditions were extremely dangerous. It was dark and cold, and strong winds at altitude were reported. The plane was flying at about 10,000 feet above the ground. Below him were forests, rivers, and mountainous areas. Cooper was wearing a business suit and loafers, not clothing designed for survival. Many experts believed that surviving such a jump would have been extremely unlikely.

Others disagreed. Some pointed out that Cooper appeared calm and confident throughout the hijacking. He had asked for specific parachutes, suggesting careful planning. He also gave very precise flying instructions, which led some investigators to believe he may have had aviation or military experience. It is possible that he knew where he was jumping and may even have had help waiting on the ground. However, no evidence has ever confirmed this.

The FBI launched a massive investigation. They interviewed hundreds of witnesses and followed thousands of leads. Suspects came from all over the country. Some were former soldiers, including paratroopers. Others were criminals, pilots, engineers, or men who had disappeared shortly after 1971. Many suspects appeared promising at first, but none could be conclusively proven to be Cooper.

One major problem was the name itself. “Dan Cooper” was almost certainly a false identity. The initials “D. B.” came from a reporting error by a journalist and became fixed in public memory. This confusion made identifying the real man even more difficult.

For years, the FBI searched the area where Cooper was believed to have landed. Helicopters flew over forests, and teams searched rivers and remote land. Nothing was found—no parachute, no body, and no equipment. Over time, many investigators came to believe that Cooper likely did not survive the jump and that natural conditions destroyed the evidence. As a direct result of the hijacking, airlines later installed a simple mechanical device known as the “Cooper Vane” on Boeing 727 aircraft, making it impossible to lower the rear stairs during flight.

In 1980, a surprising discovery changed the case. A young boy named Brian Ingram was digging in the sand near the Columbia River when he found several bundles of cash buried underground. The bills were damaged but readable. When authorities examined them, they confirmed that the serial numbers matched the ransom money given to Cooper.

This discovery proved that at least some of Cooper’s money had reached the ground. However, it raised even more questions. Why was the money buried there? Did Cooper survive the jump but lose part of the ransom? Or was the money carried by water over many years? Adding to the mystery, not a single one of the remaining 9,400 ransom bills has ever been confirmed as spent or recovered, despite their serial numbers being public for decades.

Over time, the case became part of American popular culture. Cooper was no longer just a criminal—he became a legend. Books, films, songs, and documentaries were created about him. A short wave of copycat hijackings followed in the 1970s. Even today, amateur investigators gather at events such as “CooperCon” to debate theories and examine evidence.

However, not everyone views Cooper as a heroic figure. Investigators have repeatedly stressed that hijacking a plane is extremely dangerous. Even if Cooper did not intend to hurt anyone, his actions put passengers and crew at serious risk. The mystery may be fascinating, but it is also rooted in a serious crime.

As decades passed, new theories continued to appear. Some suggest that Cooper was an experienced skydiver who planned his escape carefully. Others argue that his parachute choice and lack of survival equipment suggest that he probably did not survive. Each theory has been discussed and challenged, but none has provided a final answer.

In 2016, after more than forty years of investigation, the FBI officially suspended active work on the case. They announced that they would no longer dedicate resources to it, as they were needed for more urgent investigations. The case file remains open, but the mystery is unlikely to be solved.

Today, more than fifty years later, D. B. Cooper remains one of the most fascinating unsolved mysteries of modern history. His story combines careful planning, bold action, and complete disappearance. It raises lasting questions about identity, risk, and chance. Was he a highly trained professional who escaped successfully, or a man who made one brave but fatal decision?

What makes this mystery so powerful is not only what happened, but what remains unknown. There are no final answers and no confirmed ending. Cooper vanished into the night, and with him went the truth. In a world of digital surveillance,satellite tracking, and constant monitoring, his low-tech disappearance feels like the last great vanishing act.

More than half a century later, with the FBI’s investigation suspended but not officially closed, the questions remain unanswered: who was D. B. Cooper, what really happened after he jumped from the plane, and where is the rest of the money?

Let us know what you think in the commet section, if you have any theories or ideas. And I will see you next time with a brand new mystery for you to try and solve.

So until then, I'll see you next time. Bye~