The aircraft is supposedly a Boeing 747 (3-4-3 seating pattern in economy) but the cabin is obviously from a McDonnell Douglas DC-10, with its 2-5-2 seating pattern in economy and its oxygen masks coming out of seat back compartments.
The Boeing 747 changes color schemes several times throughout the movie, notably a white fuselage while on the ground, aqua-and-blue lines on take-off and in the air, red-and-blue lines on landing.
A flight attendant turns a lever to activate the oxygen masks, however oxygen masks on jets have a barometric switch that detects sudden changes in pressure and are deployed automatically.
Flight Management System computers on commercial aircraft don't run under Microsoft Windows 95.
The aircraft is supposed to fly a six-hour trip from New York to London, England, and would have to contain approximately two extra hours worth of fuel for contingency, yet it flies for more than 13 hours before running out of fuel. An aircraft cannot take off with that much excess fuel, otherwise it would be way above the maximum for a safe landing at the destination or alternate airport. However in the film, the chief air stewardess tries to explain that the flight is designated as "Heavy" because it contains enough fuel for the return flight, however this is an incorrect usage of the term Heavy. Heavy is used after a call sign to denote that an aircraft is capable of takeoff weights greater 255,000 lbs (115,666 kg) in the US (FAA standards) and 299,828 lbs (136,000 kg) in other parts of the world (ICAO standards). The Heavy addition reminds the tower to leave extra time for the next flight landing or taking off so the turbulence over the runway can clear.
In the beginning they show the aircraft arriving at the gate being pulled by a tow tractor AND someone guiding the plane in. In the real world you do not have both. Also on departure the plane is just rolling back from the gate on it's own. While some aircraft can power back (using the engines instead of a tractor) no airline would do this with a 747, and there would be a ground crew present.
When the news cast airs the footage of the lightning striking the plane, it shows the plane from a side view obviously in level flight. This is supposedly the footage shot by the camera operator from the airport terminal area, impossible to get the side shot shown in the news clip from where the operator was standing. It is a scene more likely to be shot from a "chase plane".
Altimeters on aircraft have the dial ranging from 0 to 9, indicating thousands of feet of altitude, and not 0 to 11. The flight deck's "altimeter" in the movie is actually a novelty clock designed to look like an altimeter.
At 33:40 into the movie the tail lights are seen blinking. This footage is from "Executive Decision" (1996).