This is the first of a two-part series. Part two is located here.More than five decades ago, a mild-mannered passenger in a business suit boarded a Seattle-bound flight in Oregon under the name Dan Cooper on Nov. 24, 1971. He ordered a bourbon and soda, and once in the air, handed a stewardess a handwritten note demanding $200,000 in cash and four parachutes under the threat of what appeared to be a bomb in his ratty briefcase. The plane landed in Seattle, and authorities complied with the hijacker’s demand. After refueling, the airliner took off again. Somewhere between takeoff and...