Dan Cooper is the pseudonym of an unidentified man who hijacked a Boeing 727 aircraft in United States airspace between Portland and Seattle on the afternoon of November 24, 1971. He extorted $200,000 in ransom () and parachuted to an uncertain fate. Despite an extensive manhunt and 45-year FBI investigation, no conclusions have been reached regarding the perpetrator’s identity and fate. The crime remains the only unsolved air piracy in commercial aviation history. The man purchased his airline ticket using the alias Dan Cooper but, because of a news miscommunication, became known in popular lore as D. B. Cooper.