Mayday at 40, 000 Feet! (1976)

A Boeing 727 airliner belonging to Transcon Airways is scheduled to depart from Los Angeles en route to New York with a pit stop in Salt Lake City. Flight 602 is under the care of Captain Pete Douglas, First Officer Stan Burkhart, and Second Officer Mike Fuller. The overall atmosphere on the flight is upbeat, despite Captain Pete Douglas' absent-mindedness because he's worrying about his wife's upcoming surgery: her doctors want to remove a lump from her breast before it becomes malignant. He's also worried about the announced snowstorm that prompted some airports to close; he hopes to get the plane to New York before the storm intensifies. The plane makes its scheduled stop in Salt Lake City, where it refuels and takes on a few more passengers, including an extradited prison inmate and his U.S. Marshals escort who are also traveling to New York. The aging Marshal has heart problems but is otherwise strong as a bull--and well-armed. He has frequent heart pains after the plane leaves Salt Lake City but tries to keep a brave face in front of his handcuffed prisoner. He makes it clear to the extradited killer that he's well-armed and won't tolerate any violence from his prisoner--who is patiently biding his time, waiting for the Marshal to slip up. If the armed Marshal could be over-powered, the inmate could grab the magnum revolver and take control of the aircraft, putting the lives of all on board in grave danger.