When William Shatner narrates the introduction, he asks the question of this flight : How could 73 of the passengers survive a crash that was classified as unsurvivable ? This suggests that only 73 passengers survived, but it is known that the number is actually 75.
The scene when National 607 makes a safe landing (before Eastern 401 crashes) shows a TWA DC-9 not a National Airlines aircraft.
When the Flight Attendants arrive into New York on another aircraft the plane they disembark from has a pointed red livery - that of another L1011 operator at the time; TWA. Eastern had a two tone blue livery. Also as they are running late to catch 401 most of the Cabin Crew leave the incoming aircraft with the passengers leaving only two Flight Attendants on board - something that would have not been permitted as there would be no Flight Attendants guarding the remaining emergency exits during disembarkation (in case they need to evacuate the passengers)
About 24 minutes into the film, there is a shot of the Lockheed-1011 at the airport terminal. However, what is shown is not an L-1011 jumbo but a Boeing 727, a medium size commercial jetliner.