Since I had no idea:<p><a href="https://en.wikipedia.org/wiki/D._B._Cooper" rel="nofollow">https://en.wikipedia.org/wiki/D._B._Cooper</a><p><pre><code> D. B. Cooper is a media epithet popularly used to refer to an unidentified man who hijacked a Boeing 727 aircraft in the airspace between Portland, Oregon, and Seattle, Washington, on November 24, 1971, extorted $200,000 in ransom (equivalent to $1,170,000 in 2015), and parachuted to an uncertain fate.
Despite an extensive manhunt and an ongoing FBI investigation, the perpetrator has never been located or positively identified.
The case remains the only unsolved air piracy in American aviation history.</code></pre>