Factual error: The whole basis of the trial and conviction of Cameron Poe is a crock. The judge can not arbitrarily mete out a sentence that is harsher based on the ability of someone to defend him/herself. In justifying the harsher sentence because of Poe's military skills, the judge effectively says that Poe is more guilty than an average person due to his honorable and decorated service in uniform to his country. In my entire time in law school, I never read one out of the literally hundreds of cases I was assigned in which a judge issued a harsher sentence because of someone's innate or learned abilities to defend themselves. But since this was a movie court room proceeding, the fact that Poe had a witness to the fight (his wife), the fact that he was injured in the fight, and the fact that his uniform was torn and otherwise ruined as a result of the fight are never examined. A D.A. wouldn't have taken this to a grand jury on a bet, because they would have never returned an indictment or "true bill."
Plot hole: The convicts remove the radar transponder from the Conair aircraft and put it aboard a tour plane to distract their pursuers. That won't work. By law the tour plane will have a working radar transponder of its own, and two working transponders that close together will show up on radar as a collision. Air traffic controllers would immediately alert emergency services who would, obviously, wonder how two aircraft that had collided had managed to stay in the air. Nobody disconnects the first transponder - Pinball carelessly tosses the second transponder under the rear seat of the aircraft (the implication being that it continues to operate, perhaps on backup battery power). He doesn't disconnect the original transponder either - Swamp Thing, a skilled pilot, does that. There is no time for him to do any of this before he is stopped by the female security guard anyway.
Plot hole: All pilots are carefully trained and have the technology to secretly transmit a code that tells air traffic control there is a hijacking in progress, without having to say a word. They also have a hijack code, something that sounds completely innocuous to you or me, but would be instantly recognisable to the airport authorities.
Factual error: In full view of police officers Cyrus murders a Federal Marshall, then he boards an aircraft which takes off despite being refused clearance. This would result in the immediate closure of the airport. It would be locked down until cleared as a crime scene which could take three or four days. All incoming flights would be diverted to their alternates and all planned outgoing flights would be grounded. How, then, does Uncle Bob's Scenic flight get clearance for takeoff?
Factual error: When the aeroplane is crash landing in Las Vegas, it follows a flight path from shot to shot that would have been physically impossible; one moment bearing down on the strip, next downtown, back to the strip, back to downtown, and back to the strip before crashing there. (01:36:00)
Factual error: The type of fire pump that would be on the ladder truck that they're driving at the end can not pump water and drive at the same time. The transmission has to be moved from "drive" to "pump". Nor could the ladder operate while driving down the road. (01:41:35)
Continuity mistake: The plane began its flight in the desert just outside Las Vegas in broad daylight (the sun was still shining). But when they reach the strip it is late at night. (01:28:00 - 01:34:50)
Continuity mistake: At the air field there is a scene when Cyrus is loading his gun. If you look closely at the clip you will see that it is hollow. You can see right through it. (01:22:05)
Factual error: In a scene during the C-123 (airplane) flight, Nicolas Cage and another man open a trapdoor in the floor on the plane and go down to a lower level to discuss their plans. This aircraft sits very low to the ground and has no lower level in any part of the cargo area. (01:00:55)
Continuity mistake: After the plane has crashed in Las Vegas, Cameron Poe rescues the bunny (his daughter's birthday gift) from the sewer/gutter. The bunny is obviously soaking wet since it had just been floating down the street in a stream of water. Later, when he gives the bunny to his daughter, it is dirty, but dry. It is clear because the ears are sticking up and bouncing, and the fur is fluffy. (01:44:50 - 01:46:35)
Continuity mistake: Near the end when Cyrus is about to get his head crushed, he falls from the carousel head first and as he falls his legs are facing the stone crusher but for some reason his head lands under the crusher not his legs. (01:44:20)
Continuity mistake: When Pinball is fighting the female guard on the plane they are struggling, and from one angle her hat has fallen off and from another angle she is still wearing it. It jumps between scenes like this with her hat being on and off. (00:24:03)
Continuity mistake: When the car hits the control tower and falls. You can see the "azz kickr" licence plate still intact. A few seconds later a crumpled up licence plate that says "azz kickr" is picked up by Colm Meany. That plate is meant to have come from the front of the car, but we've seen before there was no plate at the front. (01:28:40)
Factual error: They drive through a tunnel in Las Vegas underneath the Boulevard - Vegas doesn't have a tunnel there. (01:41:15)
Audio problem: There is a scene where Johnny 23 is on the tower and he sees all of those cars coming. He runs, and while he's running he yells "holy shi*". His mouth didn't move at all. (01:12:20)
Continuity mistake: When Malloy's car comes crashing to the ground, not only do Larkin's arms rapidly change position, his sunglasses seem to rapidly jump onto, and off, his face. (01:28:35)
Revealing mistake: Though it may be a little hard to see, when Poe is in his prison cell towards the beginning, he is doing handstand pushups. This would be really cool to see a star doing these only, you can see the strap around his foot holding him up. (00:07:25)
Continuity mistake: When we see the close-up shot of Steve Buscemi grabbing the doll, he is picking it up with his right hand. But in the next shot, when you see a wider view of him picking it up, it is now in his left hand. (01:12:55)
Continuity mistake: After Nicolas Cage pries open the door on the fire truck there is no damage to the door. (01:23:10)
Chosen answer: Poe is an ex-Ranger, and he wants to stop the criminals. Also he wanted to save the cops inside the airplane.