The story was based on the real life case of D.B. Cooper, who hijacked a Northwest Airlines 727 in November 1971 and escaped by skydiving from the plane's rear stairwell.
This story was based on the legend of D.B. Cooper, although his name was changed to R.W. Collins, and he has a vial of anthrax instead of bomb. However, Collins supposedly jumped off of a Boeing 707 which, because of the design of the plane, would not have worked. D.B. Cooper was able to jump off his plane because he was on a Boeing 727, and it had its stairway descent underneath the tail assembly.