Deliberate mistake: After the airplane loses its propeller and descends to lower altitude, the cockpit constantly shakes due to turbulence, and the flight crew complains about it in one scene. However, when the camera switches to the passenger cabin, everything remains perfectly still and serene until the airplane is on its final landing approach near the end of the movie.
Factual error: After the plane takes off from Hawaii, bound for San Francisco, there's a long shot of it flying among the clouds, with the left side well lit by the Sun. If the plane is flying east, in the northern hemisphere, then the Sun would be in the southern sky, illuminating the plane's other side.
Deliberate mistake: Throughout the movie, the din of the airplane's engines is consistently louder in the cockpit than in the passenger cabin, even though the engines are wing-mounted and therefore should be much louder in the cabin. This may have been done on purpose to allow the audience to hear the subtle dialogue in the cabin scenes. The cockpit scenes include lots of macho shouting, which is easier to hear over the engine drone.
Factual error: A stewardess arrives at San Francisco Airport after an emergency and has time to dash downtown in ten minutes for a dinner date at Ernie's Restaurant. She doesn't have to make a report or fill in any forms? Incidentally, it would have taken at least half an hour to reach Ernie's from the airport.