I know, I know, questions that even mention a movie are supposed to be in the Cafe Society. HOWEVER, since this question is really about physics, I thought it should go here…
At the end of Die Hard II the plane leaves a fuel trail to the ground and John McClane blows the plane up using his cigarette lighter. Is this possible?
I think not. I believe I read that unlike gasoline, liquid jet fuel needs to be pressurized to explode. The vapors might explode, but I think even they have to be at a high temperature to do so, and it was very cold outside in that scene. Plus, I’m not sure the stream left by the fuel leak would be substantial enough to support a flame traveling along its length. But that’s my fairly uneducated $0.02. Any organic chemists or aviation experts care to correct me?
I doubt it. I’ve never lit a trail of high octane jet fuel on fire but I have done so with a trail of regular gasoline. The speed at which the fire raced forward wasn’t all that fast (I think I could have outrun it for at least a little bit). Given that high octane fuel is even less explosive than regular auto fuel I’d think it’d resist combustion even more. I doubt it could catch an accelerating plane that is presumably travelling over 120 mph (at least I think the rotation speed for an aircraft is around this speed). Add to that the blast of the jet engines that would blow the fire backwards. Finally, I don’t think the flame could race up the fuel stream to catch the plane off the ground. Ever squirt lighter fluid on a fire? Did it race back up the stream and explode the bottle in your hand? I suppose it’s possible but I’ve seen people do this dozens of times (including WAY back in the mists of time when lighter fluid was hyper-explosive and not the wimpy stuff we get today). So far no one has blown up.
I get the impression the writer was thinking of one of Yosemite Sam’s gunpowder trails when he came up with that idea.
It’s possible for a flame to race up a moving liquid stream, as an army associate of mine experienced when pouring naptha onto a tent heater that was still lit, but in this case, the stream was moving much more slowly and comprisd of a much more easily combustable liquid over a much shorter distance.
On a related physics question, how is it possible for Bruce Willis to fall off the wing of a 747 moving at near take-off speed onto a concrete runway and survive uninjured?
and to continue the issue - just how long would the fuel on the ground burn? It certainly wouldn’t have gotten additional resources to burn from the ground (ie concrete w/a snow covering), so, how come it lasted long enough for all those planes to land?
and, and, and, just exactly how many jumbo jets can land on the same little bitty runway w/o plowing into each other?
Hmmm??
And while we’re at it, why not just contact the other planes in the sky from the radio of one of the planes in the hangar?
Sorry… Bit off topic.