Plot hole: After 1000 years have passed (without any maintenance) the Harrier jets still function like new. Amazing.

Plot hole: Travolta sends Pepper and crew to mine gold. He gives them all the equipment for mining including a working spacecraft. In essence, he is setting a "Batman Trap" by providing them the means of escape. The group waits for Travolta to depart and almost immediately leaves to train and gather weapons. For some reason Travolta doesn't notice that they are flying around the country or doesn't care.

Factual error: We see the nuclear weapon used to destroy the planet Psycho pulled out of a cruise missile. A warhead cannot be yanked out of the missile and detonated without the fissionable material being removed and built into an entirely new device. This a safeguard to keep them from being pulled out and used in exactly this way.

Plot hole: The barbarians find a working 1000 year old flight simulator. Beside the fact that the machine should not be working to begin with after such time, they were lucky enough to find a working power source in the barren wasteland.

Factual error: The "cavemen" learn to fly Harrier jets simply from reading the instructions manual. And if this isn't amazing enough, they also manage to perform maneuvers that professional Harrier pilots are not able to perform.

Revealing: When Jonny is running away from Terl in the mall at the start of the film, he goes through several panes of glass, smashing through them. One of them breaks up before he hits it.

Factual error: The tyres, rubber and plastic gaskets, belt drives, upholstery, in fact all non-metallic parts of the thousand year old jeeps, aircraft, generators and so on found by the 'Man-animals' would have crumbled to dust well within the thousand years they have been sitting around before they are discovered.

Plot hole: The heroes find fully fueled and armed 1000-year-old Harriers (AV-8Bs) on the pad at Fort Hood, Texas, in fully working order. That period of time would have rendered them utterly useless.