Dan cooper(alias) who after a miscommunication with the press and FBI was commonly known as DB whereabouts are a complete mystery. However there are several theories about what happened to him.
D. B. Cooper (boarded the plane as Dan Cooper, but a media misconception labeled him as "D.B. Cooper, which stuck) was a man who hijacked a Boeing 727 aircraft in the United States on November 24,...
he is a man who jumped out of an airplane.
D.B. Cooper is a man who hiijacked an aeroplane on November 24th 1971 in the U.S.A. and held them for $200,000 ransom. He later paruchuted out of the plane...
No one knows if Dan cooper is a real or made up name. I think it is a made up name because i don't think he would take the chance of being traced. So to answer your question no one really knows.