Plot hole: At the beginning of the film, it is still daylight, which at Christmas, would mean it's about 4:30pm at the latest. The whole incident of the film lasts around 4 hours (figured by the scene when Barnes was talking to the planes and said the trouble started around 2 hours ago coupled with the fact that not long before that, Trudeau confimed that Holly's plane had only 90 minutes worth of fuel left). So why at the very end are there shots where it appears the the sun is rising in the distance? (And no, it's not caused by the fire of the exploded plane. By that reckoning, the terroists would have had to have taken over the airport well after midnight, which is pretty much impossible since Esperanza's plane was already on route.)

Continuity: McClane's fireman's jacket gets progressively bloodier throughout the film, but around the time when he is fighting the terrorists on the planes wing, it is miraculously clean again. McClane is not wearing it, but it does get cleaner.

Continuity: When the bad guys are throwing hand grenades in to the plane to kill Mclaine, the last grenade misses the window. The camera cuts and it has gone through the window.

Factual error: The payphone McClane uses in Dulles airport has the "Pacific Bell" logo. Pacific Bell is a West Coast phone company.

Factual error: Prior to the 747 take off, a bad guy is sucked by one of the engines and all we see is blood being spit from its exhaust. Turbofans are very sensitive and may collapse by sucking a heavy bird (like a vulture), but this one stayed undamaged after sucking a 200 lb man.

Continuity: The scene where Richard Thornburg is in the aeroplane bathroom giving his live report, in a number of the shots he is holding the phone upside down.

Continuity: Bruce Willis is emerging from an underground air-vent when the plane with General Esperanza is landing. Initially the plane is coming on a direct course for him and he struggles to get out. In fact the front wheel is on course with and knocks the vent cover. But in the very next scene, the tire marks clearly show the front wheel passed to the right of the vent and so completely missed it.

Factual error: The terrorists some how raise the elevation of the airport in relation to the ILS (instrument landing system). This causes one of the jets to crash. The ILS glide slope is broadcast from a fixed antenna beside the runway, 1000 feet from the approach end. The glide slope is fixed at (usually) 3 degrees. Even if someone changed the slope (ie, degrees of slant), it would still terminate on the runway at the touchdown zone. Besides, the pilots have charts that give all pertinent information about the ILS and also have altimeters, radar altimeters, ground proximity warning systems (GPWS), and brains (duh). They would not have descended into the ground even if the terrorists had tampered with the ILS.

Factual error: When Holly's plane finally lands, the cockpit shot shows the pilot with his hands on four engine throttles. But Holly's plane is an L-1011 TriStar, which only has three engines.

Factual error: When McClane (Bruce Willis) is brought into Capt. Lorenzo's (Dennis Franz) office at Dulles Airport for the first time, Lorenzo mentions that McClane was in violation of several District of Columbia laws. Dulles Airport is in Virginia, not DC, therefore any DC laws would not apply to Dulles. (Although VA may very well have similar laws about airport misconduct.)

Revealing: In the skywalk scene, when McClane pushes the paint stand on the terrorist, you can clearly see that they use a dummy when the paint stand falls on the terrorist.

Continuity: In the beginning of the movie when John is sitting at a table in the airport smoking a cigarette, you see him notice the table with the 3 (2 white and 1 black) guys that are acting suspicious. When the black guy gets up to leave, he leans down and you see a hand grab a package. If you notice, the hand that grabs the package is white. Later when the two white guys leave, one of them leans down to grab the package and it's the same shot that was used when the black guy grabbed his package.

Revealing: At the end of the film when John and Holly get driven away on the back of what resembles a golf cart, the long shot of them clearly shows two dummies that nearly fall off when the cart sets off.

Factual error: Near the beginning of the film when John McClane goes to the pay phone and calls his wife Holly on the airplane, that is impossible. Those phones you see on the seats on the plane can only be used from the air to the ground not the other way around. Holly does answer on the plane phone and not on any cell phone she had in her purse.

Factual error: There is no airport anywhere in the world with a manhole cover in the middle of a runway.

Deliberate "mistake": I find it hard to believe that every officer in the police station managed to pull their guns on John McClane and yet not a single one of them opened fire on him, even though he was apparently firing an automatic weapon at their captain. They couldn't have automatically known they were blanks.

Revealing: Throughout the whole movie, you can see bits of 'snow' stuck to various things in close up view (i.e. guns, hair, faces, clothing). Look closely at the snow, its painfully obvious that they are little thin scraps of white plastic. Most evident is in McClane's hair when the platoon is about to move in on the church, the shot of him saying "You're not such an asshole, after all."

Factual error: After the fight with Colonel Stewart on the wing of the plane, Bruce Willis falls down from the wing. As he falls, watch the tyre-tracks near him. Those are definitely NOT the tyre-tracks of a plane. A jeep or a truck, maybe, but not a plane.

Factual error: Since the terrorists have implausibly taken over all the radios at the airport, the good guys use the marker beacons to communicate with the airplanes. Even if the marker beacons could be modified to talk rather than beep, they are directional, such that you only receive them for a few seconds as you pass over them. There is not enough time to get a message. Nor could a marker beacon be used to broadcast to a large number of airplanes. The outer marker is only 5 miles from the airport. At most, one airplane would be holding over the outer marker.

Continuity: During the last fight scene on the wing of the plane, just after the guy is sucked into the engine, general Stuart comes rushing out and yells something like "it’s time for the main event". At this, John rolls over onto his back. The shot then switches to much further away, and he is still on his stomach. The camera cuts in close again, and John is back on his back, and sliding towards the center of the wing. The camera cuts away again and shows John back on his stomach and just now rolling over.