The FBI's sketch of D.B. Cooper from descriptions given by two stewardesses aboard the hijacked flight.

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On Nov. 24, 1971 -- Thanksgiving eve -- a passenger listed as "Dan Cooper" on his ticket boarded Northwest Orient Airlines Flight 305, bound from Portland, Ore., to Seattle, Wash. The FBI believes he was the only person on the plane that afternoon who knew that it was about to be hijacked [source: New York Magazine]. Cooper, who wore a black suit and sported a sensible hairstyle, single-handedly took over the Boeing 727 airplane and held its passengers and crew hostage.

Threatening to detonate an explosive device, Cooper demanded $200,000 in $20 bills and four parachutes. (Today, that amount is roughly equal to 1 to 2.5 million dollars [source: Measuring Worth].) He directed the crew to land as planned at Seattle-Tacoma Airport. There, he released the 36 passengers and picked up the money. He directed the plane to fly toward Mexico [source: CBS News].

But the plane never made it to Mexico. It landed in Reno, Nev., with Cooper no longer aboard. At 10,000 feet above sea level, over the mountainous and remote forests of Washington state, D.B. Cooper strapped the ransom cash to his body, lowered the passenger staircase from the plane's belly, and parachuted out of the 727 and into the annals of mystery. He had pulled off one of the greatest heists in the history of crime.

More than one ballad was written of his crime, and in 1981, a film based on the hijacking supposed that Cooper survived his jump and made off with the money [source: IMDB]. His mysterious persona even turned up in another crime: In 1972, two men tried to extort $45,000 from a reporter in exchange for an interview with a man they falsely claimed was D.B. Cooper [source: U.S. District Court, Wash.].

Exceedingly little is known of the man who hijacked Flight 305. He could be anyone. His demeanor during the hijacking was calm and courteous. His name was a pseudonym. And, most importantly, his body has never been found. Is D.B. Cooper still alive? Who was he? Find out about some of the suspects on the next page.