While aircraft hijackings are a very rare occurrence in the 21st century, unfortunately, during the 20th century, they were nothing out of the norm. However, what was out of the norm is a case, where an aircraft hijacking remains unsolved to this day. This is what happened after one man took a Boeing 727 hostage. The plane belonged to Northwest Airlines, flying from Portland International Airport (PDX) to Seattle Tacoma International Airport (SEA) on November 24, 1971.