Merged No Planer calls for scientific study / Missiles of 9/11

tfk said:
I would strongly disagree with this statement.

If I were to back my car into another one at 5 mph, I would have no concern about driving away. (After I'd left my contact info, of course.)

If I were to back either a C172 or a 767 into another plane, then ... no way.
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You try to have your car OR your C172 go 500mph and see what happens.

About the 767, even a low speed collision will concentrate the energy from a very large and heavy craft into a small area, so ....

But, we are nitpicking.

As for "sturdy", it depends on the part. As mentioned above, there are no bumpers on planes, and the skin is far weaker than a car's.
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Yes, of course.

All these are side points, tho. You're original point that the planes have an enormous mass - far more than most people appreciate - is absolutely accurate.

I was trying to point out that the mass is not evenly distributed across the cross section, as seen from the front of the plane.
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I agree. But we are talking to someone who is comparing the plane with a water-filled condom.

Hans
 
Mikeys said:
If the front part got torn apart and failed to slow down the plane, how could it punch that hole?
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Numbers just for elucidation. I've got no particular interest in gathering up all the info required to do the calculations.

Let's say that the lower portion of the fuselage has sufficient mass in the first 10' to penetrate an UNDAMAGED outer wall, the upper portion of the fuselage would require about 50' to penetrate the same.

Once the nose (& especially the heavier bottom part of the fuselage) splits the outer columns, then the columns are no longer "undamaged". Once the columns have been split, it becomes very easy (i.e., consumes little work) for the columns to be pealed back and/or fractured by both the upper & lower halves of the fuselage.

In the process, the plane gets sliced up too. It is NOT "one or the other" that gets damaged. It's both.

Mikeys said:
Not all tools are designed for slicing, planes included.
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The plane is designed very well to GET sliced.
The walls of the towers, and the thin concrete floors, are designed very well to DO the slicing.

The message that you missed is that it takes much less energy to slice up a plane than it does to compact it.

tfk said:
You can't see the deceleration of the front, shredded parts of the plane on the video because, surprise, there is a wall between the shredded parts and the camera.
Mikeys said:
It's about the deceleration of the whole plane, Pinkie
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Yes, and the answer is that the disassembled, fractured, flying-around debris that used to be the front part of the plane HAS been decelerated. And it's trajectory diverted into 1000 different directions. But you can't see that debris or its velocities in the video, because they are INSIDE the building.

And the back portion of the plane has not slowed down significantly, because the thin wall of the plane cannot carry a lot of axial load.

a = F/m.

If F is small, and m is large, then a is small.

The back portion of the plane doesn't decelerate very much at all, even tho the front, sliced up portions do.

Mikeys said:
why not... if it was strong enough to demolish steel
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Because its a thin wall tube, and the forces applied at the interface of the wall have significant inward components. The tube splits & buckles at that interface, and the forces transmitted axially down the cylinder are close to zero.

Mikeys said:
me thinks you are all over the place, Pinkie.
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You don't understand impacts. You don't understand strength of structures.

Smart ass remarks incline anyone who is trying to teach you about this to toss in the towel on that effort & just point fingers & laugh at your ignorance instead.

Pinkie.

Which way do you want to go?
 
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MRC_Hans said:
You try to have your car OR your C172 go 500mph and see what happens.
Hans
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As I understand it, it was an annual tradition to get an old clunker & launch it with the catapult of one of the aircraft carriers in San Diego Harbor.

I strongly doubt that the catapult could travel nearly that fast, but it was supposed to be quite the sight.

i sincerely doubt that anyone got any more mileage out of the clunker.

MRC_Hans said:
I agree. But we are talking to someone who is comparing the plane with a water-filled condom.

Hans
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Yeah. One with quite the 'tude, too.

What are you gonna do…?

Kids. Can't live with 'em. Can't retroactively abort them...
 
MRC_Hans said:
You try to have your car OR your C172 go 500mph and see what happens.

About the 767, even a low speed collision will concentrate the energy from a very large and heavy craft into a small area, so ....
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One need only watch the various videos of large ships travelling under bridges that are lower than the upper structure of the ship. Bridge doesn't appear to move while sections of the ship are sliced away. Of course on inpsection of the bridge one sees that it too did in fact suffer great damage at the point of contact(wish I had time to find the video I am thinking of, alas I do not)
Both the ship(steel) and the bridge (concrete and a lot more steel ) suffer.

There are pictures of the damage inflicted when one ship hits another as well, where both suffer greatly.

And finally of course there are the pictures of the light Kamikazee aircraft that penetrated American warships with massive steel hulls, in cases where the aircraft's on board bombs failed to detonate.
 
Mikeys said:
If the front part got torn apart and failed to slow down the plane, how could it punch that hole? ...
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You don't understand physics. The impact is exactly what a 767 would do at 590 mph, only a fringe few don't understand that fact.

If you had a valid claim, you would present the math, the physics, etc. You have only presented what you think should happen based on nonsense.
 
Mikeys, in that video you posted of the phantom being launched into the 12 foot thick reinforced concrete block, what happened to the wingtips?
 
Hrm. Both this and the subsequent collapse seem to be examples of the truther looking at a collision (with instincts honed by collisions involving significantly less inertia) and whining, "But it should have slowed down!" I think in their minds an airplane flying into a building should be like a U-haul trailer backing into a telephone pole, only scaled up.
 
tfk said:
Once the nose (& especially the heavier bottom part of the fuselage) splits the outer columns, then the columns are no longer "undamaged". Once the columns have been split, it becomes very easy (i.e., consumes little work) for the columns to be pealed back and/or fractured by both the upper & lower halves of the fuselage.
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The nose came in first, before any heavy gear and the wings with fuel touched the wall.
In the process, the plane gets sliced up too. It is NOT "one or the other" that gets damaged. It's both.
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Slicing requires perpendicular action. No slicing of the plane took place. You are the only responder who wants to talk the actual stuff. Unfortunately your not much of a fireball.

They were decelerated by punching a hole.
And the back portion of the plane has not slowed down significantly, because the thin wall of the plane cannot carry a lot of axial load.
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It makes sense. The nose didn't take advantage of the momentum the mass of the plane had. It just punched a hole by itself.

Because its a thin wall tube, and the forces applied at the interface of the wall have significant inward components. The tube splits & buckles at that interface, and the forces transmitted axially down the cylinder are close to zero.
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Imagine a giant Pinkie, say 30 meters in length welded to the front of the plane. The pinkie is made of aluminum or wood or carbon or fiberglass. The plane with the pinkie attached hits the wall. Does it punch a hole or gets squashed before the rest of the plane meets the wall?

[/QUOTE]
 
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beachnut said:
You don't understand physics. The impact is exactly what a 767 would do at 590 mph, only a fringe few don't understand that fact.

If you had a valid claim, you would present the math, the physics, etc. You have only presented what you think should happen based on nonsense.
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No one knows what would happen. I believed the plane was real but I am not sure anymore after watching this video. Flying a plane into that tower would require a hell of a risk or at best plenty of experience form practical applications in real world.
http://www.youtube.com/watch?v=LSDfbm8OhCg&feature=related
 
Mikeys said:
No one knows what would happen. I believed the plane was real but I am not sure anymore after watching this video. Flying a plane into that tower would require a hell of a risk or at best plenty of experience form practical applications in real world.
http://www.youtube.com/watch?v=LSDfbm8OhCg&feature=related
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Hell of a risk? What risk?

And what experience is needed beyond knowing how to pilot a plane? Just aim for one of the largest buildings in New York City. How hard can that be? Do you experience difficulty passing through doors?
 
drewid said:
Mikeys, in that video you posted of the phantom being launched into the 12 foot thick reinforced concrete block, what happened to the wingtips?
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Wait, what?? Please, please tell me that this wasn't an attempt to draw a direct conclusion about the 9/11 crashes from nothing more than the Sandia Labs test footage. Does anyone realize that the "wall" was a 7 square meter block and rested on air bearings in order to move backwards upon impact? Too many people act as if the wall was barely affected while the fighter simply disintegrated, but the reality was that the entire 469 ton block was "displaced 1.83 m against the back-up structure and rebounded"*. Which, BTW, is a great deal of why it didn't take any fracturing damage or the like: They wanted to measure force of impact, so they set the block on a platform that moved so that they could measure displacement. Fracturing of the concrete would end up being a source of energy dissapation that could not be measured simply.

Yes, the test has great influence on a discussion about the forces involved during a hgh speed aircraft crash because it's data, but no, you cannot simply look at the test and conclude that because a concrete wall on an air bearings completely destroyed a fighter jet that a composite structure of steel columns and spandrels and the like would cause the same effect to a larger jetliner. This is what I mean about studying the relevant information. What it tells us is that the force in a high speed jet crash is large enough to rock a 400+ ton block over a full meter backward, so imagine what a larger jet travelling at equivalent speed could do to a rigid, constrained assembly held together at splices by welds and bolts that were already carrying their natural day-to-day loads. That's the proper way to compare things. Not just to look and say "Hey, the jet disappeared, that also should've happened on 9/11". No. Not when you actually examine the relevant details and achieve better understanding.


Source:
* "Full-scale aircraft impact test for evaluation of impact force", T. Sugano, H. Tsubota, y. Kasai, N. Koshika, S. Orui, w.m. von Riesemann, D.C. Bickel and M.B. Parks, Kobori Research Complex, Inc., Tokyo, Japan and Sandia National Laboratories, Albuquerque, NM, USA, Nuclear Engineering and Design, 140 (1993) 373-385, http://www.sciencedirect.com/science/article/pii/002954939390119T
 
Mikeys said:
Slicing requires perpendicular action. No slicing of the plane took place. You are the only responder who wants to talk the actual stuff. Unfortunately your not much of a fireball.
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Eh? The plane hit the building at close to 90° relative to the plane's long axis. Perpedicular, like pushing a carrot or a string bean through a vegetable slicer.

Mikeys said:
The nose didn't take advantage of the momentum the mass of the plane had. It just punched a hole by itself.
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And the nose took what percentage of a single frame of video to disappear? This is not high-speed high-def, so how the hell can you say what exactly happened to that quite short nose cone?
 
tfk said:
Numbers just for elucidation. I've got no particular interest in gathering up all the info required to do the calculations.
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Tom, I don't know if this helps any - and plus, you might already know about this, so if you do, just tell me to shut up, but: NCSTAR 1-2B, near the end (chapter 10) has calculations not for a nose penetration, but for wing impulse upon impacting the columns. So no, it's not exactly the specific case being discussed here, but it's still an examination of a part of the jet's impact on part of the structure.

To be clear: I am simply trusting their pressure-impulse curve graphs for column fracturing (figures 10-4 and 10-5). I simply don't have the knowledge to independently draw up my own numbers for that, plus I think it was built on computer modeling that's well beyond me anyway, but at the same time I have no reason to doubt their info. They make a compelling case to me that they've reasonably determined what it would've taken to break a WTC column, but you're the one with the background to better evaluate that than I.
 
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