So then the TWA flight 800 wasn't true?

 

There seems to be a missed nuance. The fuel-air vapor in the center wing tank was flammable. The actual liquid fuel didn't explode.

https://en.wikipedia.org/wiki/Inerting_system#Aircraft

The FAA did not consider lightweight inerting systems for commercial jets until the 1996 crash of TWA Flight 800. The crash was blamed on an explosion in the center wing fuel tank of the Boeing 747 used in the flight. This tank is normally used only on very long flights, and little fuel was present in the tank at the time of the explosion. A small amount of fuel in a tank is more dangerous than a large amount, since it takes less heat to evaporate the remaining fuel. This causes the ullage fuel-to-air ratio to increase and exceed the lower flammability limit. A large quantity of fuel in the fuel tank requires much more heat to cause evaporation. The explosion of a Thai Airways International Boeing 737 in 2001 and a Philippine Airlines 737 in 1990 also occurred in tanks that had residual fuel. These three explosions occurred on warm days, in the center wing tank (CWT) that is within the contours of the fuselage. These fuel tanks are located in the vicinity of external equipment that inadvertently heats the fuel tanks. The National Transportation Safety Board's (NTSB) final report on the crash of the TWA 747 concluded "The fuel air vapor in the ullage of the TWA flight 800 CWT was flammable at the time of the accident". NTSB identified "Elimination of Explosive Mixture in Fuel tanks in Transport Category Aircraft" as Number 1 item on its Most Wanted List in 1997.

 

When I was about 12, I and some other kids came across a newly abandoned car in a field.

The gas tank was in the open inside the trunk. I looked into the tank and could see that there was only a little gas. I made a fuse from some newspaper, inserted one end into the tank, and lit it. Another kids closed the trunk lid as we quickly distanced ourselves.

Seconds later, it exploded spectacularly, blowing off the trunk lid and the tank went about 15 feet in the air. The tank was intact, but what had been rectangular became pretty close to a sphere.

So, yes, a gas tank can explode.

Bob

 

Yes, if the vapor is inside the combustible ratio flammable limit it will burn.

 

Many years ago, when I was a member of the volunteer fire brigade, I was one of those that went to a shed fire.
There were a couple of potentially "interesting" things going on.
The room next to the shed was smoke damaged only, and when we looked inside, there was the guy's shotgun cartridge loading stuff.
The shed fire was pretty hot as the lawn mower was melted. After the fire was out, a big fiberglass speed boat on a trailer was just a heap of fibers.
The large inboard motor was sitting on the trailer chassis, and on each side were a couple of large rectangular things buried in the fiber matting. A fire fighter dragged one of these lumps off with a rake. It went rocking back and forth with a sloshing noise. We all moved hurriedly back a bit!
Yes, a couple of fuel tanks survived the center of the fire without exploding. I s'pose the fuel just boiled off and kept the air out so no bang.
It could have been quite different.

 

My neighbor’s adult kid set fire in the basement in an attempt to kill his parents. A partially filled 5 gallon gas can exploded and subsequently caused two propane tanks to explode. The rear of the house was blown away. His parents escaped.

 

Technically a can of gas in the basement fire doesn't explode or cause a detonation. It burns quickly causing a ‘Deflagration’ Gasoline vapor/air mixtures can detonate in high temp/pressure conditions. In a ICE engine that's usually a bad thing called ‘ping/knocking'.

I was told the main difference is that a Deflagration hurts, while a true explosion is painless.

 

My neighbor’s adult kid set fire in the basement in an attempt to kill his parents. A partially filled 5 gallon gas can exploded and subsequently caused two propane tanks to explode. The rear of the house was blown away. His parents escaped.

I hope the kid didn't escape punishment.

 

I hope the kid didn't escape punishment.

As a matter of fact, he did

 

If the integrity of the tank is not damaged, then there will be no explosion. For example, a fuel gauge sensor is a potentially sparking device. And nothing explodes. Too much gasoline vapor and too little air. But if you wash the tank - steam and not very well, then yes, an explosion is more than likely. Although there can be a lot of nuances. I've heard a lot of stories like "The driver shone a lighter on the head of the tank to see the fuel level and there was a fire..." or something like that. But I have never seen anything like this in person, although I have welded gas tanks many times.

 

I think people are confusing explosion and detonation. According this article, an explosion can be caused by conflagration. Detonation, on the other hand is a characterized by a hypersonic shock wave. Gas tanks can explode, but not detonate.

Explosion vs detonation


Bob

 

 

There seems to be a missed nuance. The fuel-air vapor in the center wing tank was flammable. The actual liquid fuel didn't explode.

Well another one we will have to disagree on. I had a friend (he has since passed) that was a TWA flight mechanic in the St. Louis air hub. They tried to replicate the "accident" there and couldn't do it. The day's after the accident one of the TWA big shots sent out a internal document telling the people that they were being forced to take the blame for the "accident" by the NTSB. While he and others didn't agree.

 

Well another one we will have to disagree on. I had a friend (he has since passed) that was a TWA flight mechanic in the St. Louis air hub. They tried to replicate the "accident" there and couldn't do it. The day's after the accident one of the TWA big shots sent out a internal document telling the people that they were being forced to take the blame for the "accident" by the NTSB. While he and others didn't agree.

You're not disagreeing with me, it's a disagreement with basic science and physics.

 

Worked at a chemical refinery for oil and even tanked gasoline as a solvent. There is a chartsomewhere that delineates a combustible mixture. It depends on the amount of available oxygen. Yes, there is such a thing as too much fuel and not enough oxygen to ignite. On the other hand IF the amount of oxygen in the tank is sufficient, watch out! We have a kid here whose father bought triple rinsed fuel barrels. He went to use his torch to cut the end out of one and it did ignite and the kid was hit by the flare and extensively burned but did survive with some very bad scars to show for it. They did receive an enourmous amount of money from the barrel suppliers insurance. Also interesting is BLEVE. Can't remember what it stands for but in a fire the liquid and gas in a tank expand to the point at which the tank ruptures and then you have one terrific fireball from it.

 

You're not disagreeing with me, it's a disagreement with basic science and physics.

This kind off explains why they couldn't replicate the TWA800 "accident". The vents that prevent it from happening that are part of the tank system worked. Even though this link is talking about cars.
https://vehicleanswers.com/can-car-gas-tank-explode/

 

Gas tanks don't explode...unless they are in a Pinto.

 

So then the TWA flight 800 wasn't true?

In flight 800 - the fuel to air ratio hit the correct balance. Or so they say.

Liquid fuel (gasoline) won't burn. As the video demonstrated, it was the boundary layer where the fuel and oxygen mixed within the vaporizing fuel mixed. Also, for gasoline to burn the ignition has to be sufficiently high. A cigarette won't light a bucket of fuel on fire. I know; I watched my older brother put his cigarette out in a bucket of gasoline. So for flight 800 to burst as was reported, the residual fuel that was in the center tank had to vaporize and mix with sufficient oxygen in order to become explosive. The report went on to say that the aircraft sat on the hot tarmac for a long period of time with the engines and AC units running. The AC units were blowing hot air across the belly of the aircraft adding to the temperature inside the center tank. Jet fuel (Jet-A) is hard to ignite. It takes a lot of compression and an energetic spark to get it going. You should see the size of the spark plug in a jet engine.

I've never been convinced that 800 was a self-propetuated accident. I still suspect it was accidentally shot down. Some reports came in of seeing a streak of light approach 800 before it blew up. I've never seen a missile in flight so I don't know if you would see a trail of hot gasses like that of what you see out of the bottom of a Saturn 5 rocket or a Jeff Bezos flying phallic symbol.

When I was a kid I took "something" (not going to describe this), added a very very small amount of fuel and gave it time to vaporize. Tossed a lit match into the "something" and WOOOOOOOSHHHHHHhhhhh. My buddy and I were lucky we didn't blow up the "something". A spectacular blue flame shot high above the something. We tried to repeat the fun but the oxygen inside the something had been depleted. We tried blowing air into it but got so dizzy and light headed we decided to focus our efforts on something else.

 

Once you downplay the plausible you can construct just about any possibility...

https://news.mit.edu/1997/meteorite-0409

Irving Itzkan is a tough-minded Brooklyn native who learned to argue on street corners in Brighton Beach, and he's used to having people pay attention when he expounds a theory, even if they are listening only to develop counter-arguments.

Dr. Itzkan, a research scientist in the George R. Harrison Spectroscopy Laboratory, has a theory about the crash of TWA Flight 800. He shared his thoughts--that a meteorite could have caused the tragedy last July in which 229 passengers and crew died when the airliner crashed off Long Island--and his line of reasoning with the Federal Bureau of Investigation and National Transportation Safety Board last fall.

The response?

"A deafening silence," recalls Dr. Itzkan, a Cornell graduate with a PhD in physics from New York University. "It was like I sent it down a black hole."