Question about the flight 93 crash for anyone to explain

[spooked911]

I have wondered about how strange it was that flight 93 could plow deeply into the earth such that the plane was not even visible, but still explode violently, spewing debris hundreds of feet back in the direction from which the plane supposedly came.

Supposedly the plane could penetrate so deeply into the ground (15-25 feet) because the earth was soft dirt filled in over an old strip mine. The plane in fact plowed so deeply into the ground such that you could not even see recognizeable airplane pieces at the crash site. Fine.

(This information is from Jere Longman's book on UA Flight 93-- "Among the Heroes", which portrays the official flight 93 story in more detail than one is likely to find anywhere else.)

Here's the question. Wouldn't the soft earth act much like water would to dampen any explosion?

Let's put it another way-- if a plane crashed nose first into deep water, would we expect the plane to explode?

If someone could explain how the plane could burrow into the ground AND explode massively, I'd appreciate it.

[Blackthorn]

1. ...

I think it's incredible the plane was able to penetrate the ground such that it was not even visible period. I think that's the point to make, that this is the only plane crash in history where the plane penetrated the ground far enough to disappear completely.

[The Magistrate]

2. You Misunderstand The Process, Mr. Spook

The aircraft did not bury itself in the earth and then explode, like a high explosive shell with a base fuse.

The crater was created by the combination of the striking mass of the machine at high speed, and the blast effect of the detonation of a large quantity of fuel. This latter, expanding in all direction as a bubble, would direct a goodly portion of its force into the surface of the earth, and greatly disturb it. Fuel explosions produce little blast in comparitive terms, when ranged against detonation of a similar weight of, say, gun-cotton, or picric acid, but where large quantities of fuel, particularly fuel atomized in part by the effect of high speed impacts, are involved, in absolute terms the blast effect can be very great, and in this instance, there were many tonnes of fuel involved.

The lack of "recognizeable" aircraft debris at the site is not the product of the aircraft plowing deeply into the ground. It is the result of the shattering effect against its structure delivered both by the high speed impact with the earth and by the blast of a great quantity of fuel exploding. These two things, combined more or less simultaneously, broke the machine into small fragments most effectively, and also wafted a number of the smallest fragments a considerable distance aloft.

Your question is unclear, and so difficult to answer. There is some question what you mean by soft earth or water "dampening" the explosion. The effect of an explosion tamped by earth or other weight is not reduced; it is simply re-directed, by preventing some or all of the blast being dissipated into the air. The blast wave that results moves through earth, or water, for that matter, with exactly the same force. Whether an aircraft would explode on impacting water would depend on the circumstances, with high speed and certain angles rendering it more likely. Water certainly is a resisting medium, though not so much as earth or concrete, and most people who commit suicide off a high bridge, for example, suffer sufficient damage from the impact to kill them, though often, in the unconcious state resulting, drowning does the job before internal bleeding can.

[spooked911]

3. Thanks for the thoughtful answer!

Your points are all well taken.

However, how can the plane explode upon impact into thousands of tiny pieces while the bulk of the fuselage burrows into the ground (which is what is supposed to have happened)?

Are these two opposite effects possible?

Does this make sense to you?

[The Magistrate]

4. There Are Two Forces Involved, Sir

There is the impetus of the machine itself, and there is the effect of the blast. These will in some cases be reinforcing, as a portion of the blast will be moving, at least initially, in the same direction as the machine. This will drive a good deal of the debris even harder against the ground, and while the blast wave will bounce off that suface after impacting it and disturbing it to the limit of its capacity to do so, the debris mostly will not. Some of the blast wave will, of course, be moving in the opposite direction to the impetus of the machine, and this will be sufficient, in the case of smaller and lighter fragments, not only to reverse their previous inertial course, but to direct them opposite to it, and high into the air. Some portion of the blast wave will be moving sidewise relative to the direction of the impacting machine, but given the speed at which fragments of the machine are at the same time moving towards the earth, will not have much time to disperse them away from the center of the impact. Thus you will have a pretty tight cluster of debris ringed around the impact center, and a good deal of stray material of small size aloft, in the moment after the impact. There will of course be some sports; high speed impacts and explosions are very dicey things, and chance will play a part. Some hard and heavy things that survive more or less intact may bounce or skip, jsut as other such may burrow deeper. Some small fragments may fall directly down while others catch on the wind.

[AZCat]

5. Regarding water impact force...

I read recently it is thought that the astronauts aboard the Challenger shuttle on its last flight were alive until the portion of the shuttle they occupied hit the water. The impact, however, was forceful enough to crush the cabin and they would not have survived it even though they might have survived the earlier explosion.

[John Doe II]

6. Wind theory

You write:
also wafted a number of the smallest fragments a considerable distance aloft.

Can you please explain how the official wind theory supported by FBI and NTSB that the wind blew the debris with a speed of 9 mph can be true when all eyewitness of the raining debris contradict this and there is not a single eyewitness who supports this theory. Moreover not only paper was found on Indian Lake (minimum 1 1/2 miles from crash site) but also pieces of seats, bones etc. Welcome to the thread: The official UA 93 story is a big lie!

[The Magistrate]

7. Actually, Sir

Local officials, including the Coroner, who would be certainly involved, deny any human remains were found at that location. Pieces of seats, scraps of metal, and the like, are routinely wafted such distances in energetic crashes. You would be surprised, slearly, at how whimsical the course and fall of a small piece of aluminum sheet can be, and how long it can remain aloft, if taken high initially by blast and the thermal column of a fuel detonation....

[John Doe II]

9. Sources please

When the hell did I found sources saying that bones were found on Indian Lake? See the named thread. Moreover if this for one reason or another turns out wrong: Do you have any idea about the eyewitnesses? All accounts to be found in the named thread.

[Name removed]

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[John Doe II]

15. Do you mind

just sourcing your claim and telling me why all eyewitnesses contradict the wind theory?

[John Doe II]

27. Dear Magistrate

I'm still interested in hearing any explanation how the wind can be responsable for the raining confetti....

[spooked911]

28. what was your take on the Popular Mechanics explanation for flight 93?

They seemed to think the debrtis at Indian lake was small stuff that could be blown AND that the wind was going in the right direction-- southeasterly.

[John Doe II]

8. Good question!

Here some more information for further understanding:

the crater:
“The reclaimed mine where the plane crashed is composed of very soft soil, and searchers say much of the wreckage was found buried 20-25 feet below the large crater.”
http://web.archive.org/web/20011116093836/http://dailynews.philly.com/content/daily_news/local/2001/11/15/SHOT15c.htm
(Philadelphia Daily News, 11/15/01)


The explosion:
The explosion unleashed a firestorm lasting five or 10 minutes and reaching several hundred yards into the sky , said Joe Wilt, 63, who lives a quarter mile from the crash site.
http://www.sptimes.com/News/091201/Worldandnation/A_blur_in_the_sky__th.shtml

Charles Sturtz, 53, who lives just over the hillside from the crash site, said a fireball 200 feet high shot up over the hill.
http://www.post-gazette.com/headlines/20010912somerscenenat4p3.asp


Debris around the crash site:
leaving a 200-yard swath of debris with no individual pieces bigger than 2 feet across.
http://www.sptimes.com/News/091201/Worldandnation/A_blur_in_the_sky__th.shtml

[Sweet Pea]

10. Physics 101

If someone could explain how the plane could burrow into the ground AND explode massively, I'd appreciate it.

Well.....the easy explanation is mass vs mass:

Earth (5.98 x 10 to the 24th kg.) vs 200,000 lb pressurized aluminum tube traveling at 700 feet per second.

I think I know what is going to win.

And your comment on water - water surface can be like concrete the faster and larger a body is that impacts it. Jumpers off the Golden Gate Bridge hit the water at about seventy-five miles an hour and with a force of fifteen thousand pounds per square inch. Multiply that accordingly with an aircraft traveling 400 or so miles an hour.

Soft ground has nothing to do with whether or not an aircraft explodes. An explosion, like fire, is a chemical reaction, albeit more violent in nature. You need heat, fuel and oxygen - as well as an ignition source. The rending of metal in an aircraft crash along with fuel, atomized or vapor can most times provide the spark or the flash that will ignite such a conflagration. I've seen other images of aircraft crashes that were almost vertical and at high speed. Rest assured that Flt 93's demise and aftermath was neither strange nor abnormal.

[AZCat]

12. You don't always need an ignition source

Sometimes the mixture can be pressurized quickly enough (adiabatic) to initiate combustion absent a spark.



On Edit: add/correct statement

[Sweet Pea]

16. Good point.

My HS physics class never covered that, I guess :)

[spooked911]

17. Could you by any chance find those images? I'd like to see them.

Re:"I've seen other images of aircraft crashes that were almost vertical and at high speed."

Perhaps you're right and it isn't so strange. It's just that I have a hard time visualizing the whole thing.

[Sweet Pea]

24. Spooked...

The one image I remember seeing was of a Navy bomber that flew into the ground at high speed in an almost vertical orientation. The pilot got disoriented on a night training mission and ended up pulling on his stick too hard and basically did a loop. It was in the swampy ground in eastern North Carolina, hence the total and complete obliteration of the aircraft. The engines were like 20 feet down. No image to pass on though...just the description.

[spooked911]

18. Here's the crater:

There's nice wing imprints and even a tail imprint.

How did those occur if the plane blew up?

[spooked911]

19. Question again-- who has ever seen a plane that crashed like this?

In other words, just a crater, no large debris anywhere, and fire and debris spewed off to one side (to the top right of this photo)?

If so, can you provide a link to a photo of a similar crash?

Thanks!

[k-robjoe]

20. Here you are

Similar crash. I came across this on another discussion board.

All that´s needed is to find out what happened next...

http://w1.rob.com/pix/B52_crash/B52CRSH2

[k-robjoe]

21. Better still

http://www.big-boys.com/articles/planescrash.html

[OmmmSweetOmmm]

23. I can't see where your photo and video correlates to the

question asked. All I observed were horrible crashes and no close-ups of the aftermath.

[Wilms]

22. Do I have it right?

Is the idea that the plane came down pretty much at a right angle?

That's not like skidding across a field. Everything happens in one place. The "smack" force, the explosion. Seems a harsh environment, to me.

And couldn't the wings hit the dirt, imprint it, then fold up, and join the conflagration? That seems possible.


That said, I don't know if that's 93, or even a plane at all. And were it 93, what sealed it's fate?

A Rumsfeld comment CNN taped and aired during his trip to Iraq over the holidays, referred to a missile. :shrug:

[spooked911]

25. I'm not saying it is completely inconceivable-- just that it is odd

particularly not having any large debris around.

Some people have suggested the crater is actually a hoax-- that a plane didn't really crash there.

[Wilms]

26. Might be a hoax.

I mean, how lucky to hit an abandoned mine.