On November 24, 1971, a man supposedly named Dan Cooper (also referred to as D.B. Cooper) approached the Northwest Orient Airlines counter in Portland, Oregon, and purchased a one-way ticket to Seattle, Washington.
The man, who appeared to be in his mid-40s, looked like any other passenger.
He was wearing a business suit with a black tie and horn-rimmed sunglasses, and while the plane was waiting on the tarmac, he ordered a bourbon and soda.
Watch the trailer for Stan's The Mystery of D.B. Cooper below. Post continues after video.
Shortly after takeoff, the man handed flight attendant Florence Schaffner a note.
Schaffner was used to being slipped notes scrawled with phone numbers or hotel rooms numbers by male passengers.
But this time was different.
"Just as we were starting to roll down the runway, the flight attendant next to me handed me this note," fellow Northwest Orient Airlines flight attendant Tina Mucklow shared in Stan's The Mystery of D.B. Cooper.