You also see them change the runway's height property or something like that, but an airplane can meassure altitude right?
grisel: hmm..well i went back and watched that particular segment of the movie.
The plane was low on fuel. it wasn't out of fuel because the engines would have stopped. however, its more dramatic for the captain to say he had 230 passengers flying around on petrol fumes. personally, i don't think the plane he was flying could hold 230 people. and jets fly on aviation kerosene, not petrol as the pilot stated.
But…even with kerosene vapor in the tanks, if you slam into the ground at 130 mile per hour landing speed, its going to amount to one heck of a large amount of potential energy. that, and the residual of just a few gallons of kerosene turned to vapor, amounts to one heck of an explosion. so its possible.
incidently, as a former OSH person, one of my really pet peaves is hearing people talk about fumes when they talk about gas or hydocarbon fuel type explosions. sure, it common veniculer to say "the gasoline fumes exploded". however, what explodes is not fumes but vapor mixed with the correct ratio of air or oxygen to support an explosion. fumes are heat or fire related particulants: vapors are the gaseous forms of liquids.
another aspect of the movie was the re-calibration of the glide slope information for the instrument landing system. when the pilot put the plane on essentially the auto landing system that used the signals from the misdirection of 200 feet difference, well good movie item also. but the planes do have a radar altimeter that measures height above the ground independent from what the auto land signals give: close proximity with the ground alerts the pilots with warning lights and sirens and god knows what else. Once again, just more plausible drama.
still a good movie.
The plane didn't run out of fuel, it was about to. Fuel is most explosive when it is about 1 to 15 parts of air.
They recalibrated the ILS to minus 200 feet. Really, that wouldn't work. An ILS only gives you a localizer (to line up with the runway) and glide slope… it doesn't tell you altitude. Giving the plane a false altimeter setting would work a lot better… assuming the plane didn't have a radar altimeter the pilots were monitoring or a Ground Proximity Warning System. And it would only work if the ceiling was almost zero… otherwise they'd just go visual, adjust the plane's path, and land.
You also can't calibrate an ILS like that… it's based on the fixed location of the antennas and two lobes of different signal strengths. If you weakened one of the lobes, the plane either wouldn't be able to capture it because it is too shallow (glide slopes are always captured from below, not dove upon which can give false indications or result in too high sink rates) and if they made it too steep, the pilots would have executed a missed approach because of the excessive sink rate required to follow the slope.
Of course, the whole thing is preposterous. There are tons of other airports they could have gone to that the terrorists couldn't have controlled (like the planes that weren't in the holding pattern did) and even with lost com.. no pilot would have ever stayed in a holding pattern until fuel exhaustion. They'd bugger off to their alternate… which regulations require to have significantly better weather than their primary destination and the required fuel to get there.
Die Hard 2 was the single stupidest movie ever made. Not a thing in it was plausible or possible. The bad guys plan was to take over the control tower at Dulles and to keep planes circling till they ran out of fuel- ignoring the fact that there are 3 other airports within minutes of Dulles, that pilots have many channels of communication, and that in an emergency (and low fuel is an emergency), pilots can take any action necessary for the safety of plane. They would not mindlessly circle until the engines flamed out.
The other "Evil Deed" they did was change the glide slope by pressing a few buttons – which is physically impossible – they did not just change the angle, they moved the glideslope so it lead to a well short of the runway- that would require erecting a new glideslope transmitter at that spot.
The direct answer to your question, is no, a plane with no fuel would not explode.
Die Hard Plane Crash
A full gasoline or similar volitile fuel tank will NOT explode. You just get a LOT of fire. An empty tank has fuel vapors already mixed with oxygen so that it will burn so fast that it causes an explosion. Diesel vapor will not explode like that. Jet A is between gasoline and diesel. That was a movie. In most cases when gaseous explosion are required, propane is used since it is a gas at normal temperatures and pressures.
You know Die Hard 2 is fiction? A plane that crashes and doesn't explode doesn't make for a good movie. In movies you only have to shoot a car and it explodes. In reality it doesn't. Cops hide behind car doors in gun fights. A car door is as much use as a piece of paper in stopping a bullet.
Don't believe anything you see in a movie. It's all fake. Any explosions you see are staged and manufactured by the special effects crew.
Altitude is read from sea level. You have to allow for the elevation of the airport, that is its height above sea level.
It's the elevation that was altered on the ILS. You have to remember that it was a Die Hard movie tho!
It's just a movie. It's not real.