Factual error: The scene in which the Beechcraft Baron hits the Boeing 747 in flight plumbs new depths in cinematic absurdity. Assuming both aircraft are at their normal cruising speeds - they appear to be - and the Beechcraft has half a fuel load left, it will hit with the same energy as 7,700 kgs of TNT. The Beechcraft Baron weighed 3,200 kg and the two aircraft would have a closing speed of something like 700 kmh. Even a glancing blow would tear the entire front half of the 747 to bits - there would be virtually nothing of the fuselage left intact all the way back to the wings, and the film shows the two aircraft on course for a head on collision.
Factual error: The 747 takes off from Washington D.C., while there's still some daylight, toward the west coast. Due to complications it's diverted to land in Salt Lake City. The Sun goes down and the plane is shown flying all night long. The Sun even comes back up before they get to Salt Lake. Really, how could it take that long for a jumbo jet to fly a measly couple of thousand miles?
Factual error: When the 747 finally lands it makes a hard left turn at the end of the runway. The cutaway to the passengers shows them all leaning to the Plane's left side (due to bodily inertia). For a left turn they should all be leaning to the right.