The third season. - Dan Cooper's Story

At Portland International Airport, a man named Dan Cooper boarded a flight to Seattle. After takeoff, he handed the flight attendant a letter and asked her to read it alone. As soon as she read the letter, she was stunned and immediately went to the captain.The letter contained something shocking... but what was its content?And who was Dan Cooper?The details of one of the strangest and most famous cases in American aviation history.