Author Topic: question (Read 594 times)

killnu · « **on:** February 06, 2005, 01:06:46 PM »

i had a empty fuel tank catch fire and blow plane up, is that right?

Urchin · « **Reply #1 on:** February 06, 2005, 01:12:39 PM »

I'd imagine there could still be fumes left in there that could explode.

killnu · « **Reply #2 on:** February 06, 2005, 05:41:48 PM »

i figured the fumes woulda leaked out with the fuel from the hole that was put in it much earlier, hence the empty tank.

hmm....could be tho.

SuperDud · « **Reply #3 on:** February 06, 2005, 09:33:30 PM »

Many investigators believe that TWA Flight 800 was brought down do to a spark in a tank with only fumes in it. They actually stated that if this tank woulda been full the spark MIGHT not have brought down the plane on account that the fumes are more combustable than the actual fuel. Just some food for thought:)

streetstang · « **Reply #4 on:** February 06, 2005, 10:29:52 PM »

Take a gas can that has a little gas left in it.

Empty it out.

Now for the fun part.

Stand back, light a match, and toss it towards the can in the area where the open top is. (Note: the match should land fairly close to the open top)

Then

POOF. It sorta looked like a jet for a minute then fizzeled out.

Saw some dipchit doing this at a frat party a few years ago. Was funny at the time with with alot of beer in me but I realized the stupidity of it all soon after. But it just shows that empty tanks still have vapors in them and those vapors can splode.

im911 · « **Reply #5 on:** February 06, 2005, 11:36:13 PM »

One time (a long time ago when I was younger) my friend and I decided it would be fun to empty an entire Aqua Net hairspray can (one of the big ones) into the 5 gallon water bottles you get delivered to your home.

It took about 5 minutes of constant spraying before the can was emptied and in the bottle hung a think cloud of hairspray fumes. I don't know why, but I was the one holding the bottle with the flat bottom end against my chest on my knees in the middle of my friend's apartment.

Now comes the fun part.

He lit a match at the opening which when ignited, sounded like a jet engine in the middle of the living room. I flew back about 4-5 feet and from the sound the windows made, I thought for sure one or all of them were blown out. Luckily they weren't.

Well, we both lived and had to change our underwear but learned a valuable lesson in physics.

Moral: Don't be stupid.........

Widewing · « **Reply #6 on:** February 07, 2005, 12:06:16 AM »

Yes, empty tanks present a greater danger of explosion than full tanks. Virtually the entire tank contains fumes. Remember, it's the fumes (atomized fuel) that burns, not the fuel itself. IIRC, Lavochkins used exhaust gases to purge fuel tanks to minimize the risk of fuel tank explosions. I doubt that this would ever be modeled though.

My regards,

Widewing

killnu · « **Reply #7 on:** February 07, 2005, 10:49:53 AM »

ok, but, if the tank had a bullethole(s) in it, still flying around, wouldnt those fumes be purged by the air?
obviously it wasnt, but i thought it woulda been, thats why it was odd to me.

Ghosth · « **Reply #8 on:** February 07, 2005, 12:14:30 PM »

I've known guys trying to weld a rusted out fuel tank who.

A Emptied the tank.
B Steam cleaned the tank.
C Flushed it 3 times with water
D still almost killed themselves when the welding ignited vapors left in the tank.

Aubrey · « **Reply #9 on:** February 07, 2005, 01:03:41 PM »

I used to work at a big oil/gas tank farm. One day we found we had a hole in the tank. Heh they happen more often than you think. Any way we had hole near the top of the tank. We needed to weld it

soooooooo they filled the tank all the way up to the top, then a guy got on the outside of the tank and welded it pretty freaky when we saw the trail of flame. See Gas does not burn as a liquid. It is only when it evaporates into a gas that it does burn.

Hence empty tanks of any kind are more likely to explode than any kind of full tank.

2bighorn · « **Reply #10 on:** February 07, 2005, 07:10:17 PM »

Quote

Originally posted by Widewing
I doubt that this would ever be modeled though.

Probably because La-9 was first to have it.

Widewing · « **Reply #11 on:** February 07, 2005, 07:20:42 PM »

Quote

Originally posted by 2bighorn
Probably because La-9 was first to have it.

That would explain it.

My regards,

Widewing

Cobra412 · « **Reply #12 on:** February 07, 2005, 11:06:18 PM »

Even when you purge a tank using air it still doesn't get rid of all the fumes which are your biggest hazard. I've installed quite a few wing probe harnesses on the F-15 and I can tell you that without a doubt there is still a ton of fumes even with a depuddled and purged tank. We use a hose that's about 3 ft around with a decent amount of suction and it doesn't get rid of the fumes that well. This is with two panels open that you could easily fit your head into.

I'll see if I can find it but an Israeli F-15 burnt to the ground in just under a few minutes from static electricity when it was inside the fuel barn. From what I can remember of the accident report is the plane was being purged and a maintainer went to reground the jet after the grounding line had been accidentally disconnected. Static electricity set off the tank that was being purged. I'll see if I can find a link.

Only thing I could find was the incident of the Israeli F-15 landing with only one wing. Will see if I can get the photos from work. Not sure we still have them though.

grmrpr · « **Reply #13 on:** February 08, 2005, 09:01:28 AM »

Aircraft have 2 fuel values per tank. Total fuel in tank and usable fuel. For example a Cessna may have 23 gallons per wing and weight calculations are made on that value but useable fuel is only 20 gallons. And as mentioned above a mostly empty tank is much more prone to explosions than a full one. A full tank is o2 deprived. A empty tank with fuel vapor is very o2 rich.

GrmRpr