What happens when an aircraft hits something that is not inclined to move?

[Furcifer]

acceleration, last I heard was the time rate of change in velocity.

a= del v/del t

if del v= 0 we've got a problem. well I don't, I get a=0. so without the change in velocity, or a constant velocity, F=ma, reduces down to..... yah 0. You don't have to keep it this simple though, I'm not an engineer.

 

[fezzic]

Just to observe. I am sure someone would have done this.

AC stopped | Force (in x meters) | (x10^6N) 1 | 3,875 10 | 388 20 | 194 30 | 129 40 | 97 50 | 78 60 | 65

Apollo20, you show that NIST figures are low in comparison to the quick calculation you made given the assumption of how far into the building the aircraft penetrated before "stopping". So why is the 320 and 380 MN figures more correct than what you just calculated here? I am sure I am missing something.

Not that it invalidates your position, I note that the 767 is about 48 meters in length. An assumption that the aircraft only penetrates 20 meters would mean that the front 28 meters of the aircraft would have to be crushed, dismembered, whatever, in order for the end of the aircraft to not stick outside the building.

I think it possible that whoever did the calculation at NIST must have assumed that the aircraft penetrated far enough that, assuming it didn't fold up and crumple while passing through the building, it would be completely within the building. I suppose that the assumption might allow for a determination of the minimum force the aircraft would have exerted since it would then account for the aircraft disappearing completely within the building with a minimum need to guess where it actually stopped.

Yay! The forum newletter told me how to do a table! Yay!

 

[LashL]

From most of the things I have seen, it's believed that the plane wreackage make it right the way across the towers.

Why would you assume something that the evidence demonstrates is not true?

Given that some of the aircraft debris went right through the towers and out the other side, and given that the video and photographic evidence indicates the aircraft impact moved debris (both aircraft and building contents) right against the opposite wall, I'd say your assumption is a very bad one.

-Gumboot

Indeed.

Even if one uses Apollo20's formula (although it is wide open to debate how accurate or how inaccurate it is), one need only utilize the figure of 51m (in the ~63m wide building) to come up with the 75 MN result that NIST came to.

I am not an engineer, of course, but as I said above, I recognize sophistry when I see it.

 

[Furcifer]

not biting on that I see. your not gonna say "no, but there was a constant change in velocity, even as it struck the exterior, then came to a complete stop before even reaching the core" which is what this amounts to, and is highly speculative as best.

 

[Apollo20]

Fezzic:

Thanks for the nice table!

So, let's go over this one more time (mostly for the benefit of 3bodyproblem and our lawyer turned scientist)!

The initial velocity of the aircraft was 250 m/s (approx!).
The plane struck WTC 2 and penetrated into the structure.
Wierzbicki calculates (as we also observe) that the perimeter wall offered very little resistance to the aircraft - about 3 % of the initial KE to be exact.

Things really start to happen when the aircraft strikes the core which offers a resistive force that shreds the aircraft.

Omika et al. calculate the impact load time history for WCT 1 & 2. In both cases it is approximately triangular and, for WTC 2, peaks after about 0.1 seconds at a value of about 375 MN. Without velocity reduction this means the aircraft has moved about 25 meters into the building. But, 3bodyproblem, please recognize that there WAS velocity reduction - this is why I used v^2 - u^2 = 2as. If we assume that the aircraft was brought to rest after a distance of s, we have u = 0, and v^2 = 2as. I guestimated that s ~ 20 meters and did my calculation, which from Fezzics table leads to a resisting force of 194 MN. (Or 97 MN if we consider the average acceleration as 1/2 the peak)

Mendis et al. calculate an impact load-time history for a Boeing 767-300ER travelling at 140 m/s striking a "typical tall building". The load profile is triangular and peaks at 320 MN.

Riera's formalism leads to a triangular load profile and for A Boeing 707-320 travelling at 103 m/s the peak resistive foce is estimated to be 88 MN. And please note this is a low speed 707!

T. Sugano et al. measured, (Yes, measured!), the impact force vs. time profile for a F-4 Phantom jet weighing 19 tonnes and travelling at 215 m/s striking a concrete block mounted on air bearings. The peak impact load was found to be about 180 MN.

Now when we look at NIST's treatment of this problem, well, we have a problem!

First of all NIST assumes that the aircraft travelled 60 meters inside the building . NIST also show an acceleration profile for the aircraft (Figure 2-45). This STARTS at about 60 g's, (equivalent to about 75 MN), and drops off in a linear fashion to zero in about 0.6 seconds.

THIS CANNOT BE CORRECT!

As we have seen, the load profile is approximately TRIANGULAR, starting from zero, increasing to a maximum and then falling back to zero.

Also NIST's calculation assumes the resistive force starts when the aircraft strikes the perimeter wall. This is strictly true, but remember Wierzbicki has shown that the perimeter wall offered very little resistance. If this was not true we would have seen the aircraft smashed to pieces OUTSIDE of the tower. Since this did not happen, and using Wierzbicki's estimate of 3 % of the initial kinetic energy expended to penetrate the exterior wall, we can safely assume that the resistive force only begins when the aircraft strikes the CORE!

Therefore I am sorry to say NIST really messed up on this calculation. Its load profile is non-physical and its stopping distance is too long.....

CASE CLOSED

Oh, one more thing:

Sophism is an argument that is correct in form or appearance but is actually invalid.

Looks like NIST is the guilty party here!

 

[rwguinn]

Stick to Chemistry and chemical energy, Doc. You don't know Jack about structures and impacts.
CASE CLOSED

 

[Max Photon]

Max Photon suggests Apollo20 use Paul's Magic Filter to eliminate pesky MILDEC noise

Fezzic:

Thanks for the nice table!

So, let's go over this one more time (mostly for the benefit of 3bodyproblem and our lawyer turned scientist)!

The initial velocity of the aircraft was 250 m/s (approx!).
The plane struck WTC 2 and penetrated into the structure.
Wierzbicki calculates (as we also observe) that the perimeter wall offered very little resistance to the aircraft - about 3 % of the initial KE to be exact.

Things really start to happen when the aircraft strikes the core which offers a resistive force that shreds the aircraft.

Omika et al. calculate the impact load time history for WCT 1 & 2. In both cases it is approximately triangular and, for WTC 2, peaks after about 0.1 seconds at a value of about 375 MN. Without velocity reduction this means the aircraft has moved about 25 meters into the building. But, 3bodyproblem, please recognize that there WAS velocity reduction - this is why I used v^2 - u^2 = 2as. If we assume that the aircraft was brought to rest after a distance of s, we have u = 0, and v^2 = 2as. I guestimated that s ~ 20 meters and did my calculation, which from Fezzics table leads to a resisting force of 194 MN. (Or 97 MN if we consider the average acceleration as 1/2 the peak)

Mendis et al. calculate an impact load-time history for a Boeing 767-300ER travelling at 140 m/s striking a "typical tall building". The load profile is triangular and peaks at 320 MN.

Riera's formalism leads to a triangular load profile and for A Boeing 707-320 travelling at 103 m/s the peak resistive foce is estimated to be 88 MN. And please note this is a low speed 707!

T. Sugano et al. measured, (Yes, measured!), the impact force vs. time profile for a F-4 Phantom jet weighing 19 tonnes and travelling at 215 m/s striking a concrete block mounted on air bearings. The peak impact load was found to be about 180 MN.

Now when we look at NIST's treatment of this problem, well, we have a problem!

First of all NIST assumes that the aircraft travelled 60 meters inside the building . NIST also show an acceleration profile for the aircraft (Figure 2-45). This STARTS at about 60 g's, (equivalent to about 75 MN), and drops off in a linear fashion to zero in about 0.6 seconds.

THIS CANNOT BE CORRECT!

As we have seen, the load profile is approximately TRIANGULAR, starting from zero, increasing to a maximum and then falling back to zero.

Also NIST's calculation assumes the resistive force starts when the aircraft strikes the perimeter wall. This is strictly true, but remember Wierzbicki has shown that the perimeter wall offered very little resistance. If this was not true we would have seen the aircraft smashed to pieces OUTSIDE of the tower. Since this did not happen, and using Wierzbicki's estimate of 3 % of the initial kinetic energy expended to penetrate the exterior wall, we can safely assume that the resistive force only begins when the aircraft strikes the CORE!

Therefore I am sorry to say NIST really messed up on this calculation. Its load profile is non-physical and its stopping distance is too long.....

CASE CLOSED

Oh, one more thing:

Sophism is an argument that is correct in form or appearance but is actually invalid.

Looks like NIST is the guilty party here!

Apollo20,

Remember, I claim the NIST reports do not lie, but rather, tell the ambiguated truth.

The need to engineer plausible deniability means that the NIST reports will hide the ambiguated truth in plain view.

So let's use Paul's Magic Filter to eliminate the MILDEC noise that is being used to ambiguate (cloak) the truth in plain view.


You noted that NIST puts the perimeter resistance at zero. Now why would NIST do this?

NIST is telling the truth!

Small amounts of thermite in box columns of impacted panels were ignited just moments before the jets crashed.

In this video, watch the flashes occurring right at WTC2/81/NE corner, right before impact.

Video: 2nd hit - north face cropped
http://www.youtube.com/watch?v=v2oUD1XWmB8
(Click on the video viewer's lower right icon to watch in Full Screen mode.)

I claim the white flashes are from lasers aimed from WTC7 being used to ignite thermite-dusted shock-tube branches.

This meant that impacted panels' A325 splice bolts were ductile on impact, hence the negligible resistance. (NIST does not lie.)

(Incidentally, note the white flashes on the east edge of WTC1 at the impact floors, right after 175 hits WTC2. Demolition planners are hiding work behind peak emotional moments.


Now, you also pointed out that NIST's acceleration profile does not match the acceleration profiles of jet impacts produced by others.

I leave it to you as an exercise to take NIST's acceleration profile at face value, and work backward.

Ask yourself: What would produce NIST's acceleration profile?


I'd be curious to see what comes up for you.


Great post, by the way.


Cheers!

Max

* * *

 

[rwguinn]

All this is what happens when people who almost know, or who think expertise in one area extends to all areas.
The acceleration spectrum for the building would be sinusoidal in nature--or "triangular" if you prefer.This is due to the huge mass and low frequency nature of the beast.
The acceleration spectrum for the airplane would be very nearly a "step function". Although it too would be "triangular", the build-up (due to the (relatively) low mass) would be of considerably shorter duration than the decay, and would, for all intents and purposes, look like a step function when plotted on a graph with reasonable units on the time axis.
An accelerometer on, say, a glass window that was impacted would show an essentially instantaneous jump from zero to several thousands of g's.
It all depends on where you are. Using the aircraft simulation to describe the building reaction, and vice versa, is intellectually dishonest.
So what is your point, Dr. Greening?

 

[KingMerv00]

You noted that NIST puts the perimeter resistance at zero. Now why would NIST do this?

NIST is telling the truth!

Small amounts of thermite in box columns of impacted panels were ignited just moments before the jets crashed.

In this video, watch the flashes occurring right at WTC2/81/NE corner, right before impact.

Video: 2nd hit - north face cropped
http://www.youtube.com/watch?v=v2oUD1XWmB8

(I claim the white flashes are from lasers aimed from WTC7 being used to ignite thermite-dusted shock-tube branches.)

This meant that impacted panels' A325 splice bolts were ductile on impact, hence the negligible resistance. (NIST does not lie.)


* * *

The flashes happen on the side facing AWAY from the impact sight. Lasers would need to be shot through the building.

I simpler explanation would be reflections.

 

[Drs_Res]

Originally Posted by Max Photon
In this video, watch the flashes occurring right at WTC2/81/NE corner, right before impact.

Video: 2nd hit - north face cropped
http://www.youtube.com/watch?v=v2oUD1XWmB8

(I claim the white flashes are from lasers aimed from WTC7 being used to ignite thermite-dusted shock-tube branches.)

The flashes happen on the side facing AWAY from the impact sight. Lasers would need to be shot through the building.

White lasers, I think there may be a problem with that.

I simpler explanation would be reflections.

Or artifacts on a compressed youtube video.

 

[Bell]

The flashes happen on the side facing AWAY from the impact sight. Lasers would need to be shot through the building.

I simpler explanation would be reflections.

Not the 'mysterious asplosion' again?!

I hold to my believe that it is energy that is realesed as soon as the nose hit the tower. Watch the video from the Phantom, and in the side shot (left side) you'll see a similar flash/explosion as soon as the jet's nose hits the concrete, allthough some smaller.

ETA: My bad, different flashes...

 

[KingMerv00]

White lasers, I think there may be a problem with that.

Heh.

Or artifacts on a compressed youtube video.

I hear "compression artifact" a lot in here. Enough to make me curious as to what the hell people are talking about. Little help?

 

[uruk]

Heh.



I hear "compression artifact" a lot in here. Enough to make me curious as to what the hell people are talking about. Little help?

A compression artifact is caused by shrinking down the resolution and files size of an image or video file. Jpeg and Mpeg are notorious for compression errors because of the "lossy" nature of the algorithym used.
The algorithym reduces the number of pixels by averaging the color of the surrounding pixels and reducing it to a single pixel. This sometimes causes color errors so you get a fuzzy pixelation effect especialy along edges or boundries between two colors.
I remember Christophera confusing mpeg pixel artifacting for rebar or someother thing

Hope that helps

 

[KingMerv00]

A compression artifact is caused by shrinking down the resolution and files size of an image or video file. Jpeg and Mpeg are notorious for compression errors because of the "lossy" nature of the algorithym used.
The algorithym reduces the number of pixels by averaging the color of the surrounding pixels and reducing it to a single pixel. This sometimes causes color errors so you get a fuzzy pixelation effect especialy along edges or boundries between two colors.
I remember Christophera confusing mpeg pixel artifacting for rebar or someother thing

Hope that helps

It does help. Well helps me anyway. I doubt Max will take it to heart.

 

[Terral]

No 100-Ton Jetliner Crashed Anywhere Near The Pentgon

Hi Furrod:

Yes, I am brand new. This is funny, because I cannot even quote your link from the OP. :0)

Furrod >> I don't know if this video has been discussed before, but I figure it is relevant to anyone wondering why there weren't more recognizable aircraft pieces on 9/11.

There was no Jetliner debris in the field outside Shanksville, because Flight 93 never crashed anywhere near that empty field. Flight 77 never crashed anywhere near the Pentagon either, which is why the E-Ring entry hole measured only 18’-3” and only two windows were missing from the second floor. Since all the windows on the third floor remained unbroken after the attack, then obviously an almost 50 feet tall Jetliner never crashed there. Your video shows an F-4 Phantom Jet less than one seventh the size of Flight 77 crashing into a 10-feet concrete wall to test the wall. The Pentagon is built with primary masonry walls using limestone-clad facing and limestone is one of the softest stones on earth. Even granite would not stop a 100-Ton Jetliner going over 500 miles an hour. Try to calculate the amount of energy from that impact without a calculator. :0)

The Boeing 757-200 Jetliner has two 5.5-Ton Rolls-Royce engines not to mention 60 tons of high grade aluminum, massive wing sections, landing gear, seats fuselage and a massive tail section standing almost 50-feet tall off the tarmac. The Wedge One E-Ring wall between Column Line 8 and 18 had two vehicles (Nissan and SUV) with many 6-feet tall cable spools untouched by anything. The oversized spools had cable still wrapped around with the black plastic coating still very much intact, not even melted, and the distance up to the still-intact second floor was a mere seven feet. :0) No sign of any Rolls-Royce RB221 engines were ever found anywhere near the Pentagon, because no Boeing Jetliner ever crashed there.

GL,

Terral

 

[Max Photon]

Max Photon brilliantly discusses the white flashes on the north faces of the WTCs

The flashes happen on the side facing AWAY from the impact sight. Lasers would need to be shot through the building.

I simpler explanation would be reflections.

You are not understanding.

Thermite was placed (among other places) in box columns to be hit by the jet.

Flight 175 hit on the south side.

Since everyone would heavily investigate the impact face, MILDEC planners lit the thermite in the south columns by running thermite-dusted shock-tube lines around to the opposite (north) face, which would get considerably less scrutiny.

Note that lighting the thermite-dusted shock-tube with lasers was done right as the jet approached, again, to cloak the nefarious activities behind peak emotional moments. (MILDEC is exploiting both spatial and emotional susceptibilities.)

As I said in another post, note how similar flashes occur on WTC1's NE edge, particularly concentrated around the impact floors - the floors that are to be heat-weakened by thermite planted at steel connections and splices.

Note that WTC1's flashes are cloaked by two different peak emotional moments: the impact of 175 into WTC2, and the collapse of WTC2.


Those who say the flashes are compression artifacts are doing some terrible science.

While compression artifacts are a viable hypothesis, the peculiar timing of the flashes relative to catastrophic events, and their amazing concentration at impact floors, should give even the densest pause.


Max

* * *

 

[funk de fino]

Hi Furrod:

Yes, I am brand new. This is funny, because I cannot even quote your link from the OP. :0)




There was no Jetliner debris in the field outside Shanksville, because Flight 93 never crashed anywhere near that empty field. Flight 77 never crashed anywhere near the Pentagon either, which is why the E-Ring entry hole measured only 18’-3” and only two windows were missing from the second floor. Since all the windows on the third floor remained unbroken after the attack, then obviously an almost 50 feet tall Jetliner never crashed there. Your video shows an F-4 Phantom Jet less than one seventh the size of Flight 77 crashing into a 10-feet concrete wall to test the wall. The Pentagon is built with primary masonry walls using limestone-clad facing and limestone is one of the softest stones on earth. Even granite would not stop a 100-Ton Jetliner going over 500 miles an hour. Try to calculate the amount of energy from that impact without a calculator. :0)

The Boeing 757-200 Jetliner has two 6-Ton Rolls-Royce engines some 9-feet in diameter not to mention 60 tons of high grade aluminum, massive wing sections, landing gear, seats fuselage and a massive tail section standing almost 50-feet tall off the tarmac. The Wedge One E-Ring wall between Column Line 8 and 18 had two vehicles (Nissan and SUV) with many 6-feet tall cable spools untouched by anything. The oversized spools had cable still wrapped around with the black plastic coating still very much intact, not even melted, and the distance up to the still-intact second floor was a mere seven feet. :0) No sign of any Rolls-Royce RB221 engines were ever found anywhere near the Pentagon, because no Boeing Jetliner ever crashed there.

GL,

Terral

You have no idea what you are talking about do you?

dont make people come in here and ridicule evry false claim you have just made in that post

run away now while you have the chance

 

[KingMerv00]

Lasers aren't white.

Why use light anyway when radio waves are invisible?

 

[Terral]

Please Try To Refute One Word From Any Of My Posts :0)

Hi Funk De Fino:

Thank you for the quick response:

Funk De Fino >> You have no idea what you are talking about do you?

Of course I do. Please take a little longer next time in preparing your rebuttals, so as not to embarrass yourself in front of all these nice people. :0)

Funk De Fino >> dont make people come in here and ridicule evry false claim you have just made in that post run away now while you have the chance

Every registered member here has the right to present his 911Truth explanations exactly as he sees them. Right? You can write fancy posts and support your claims using any third-party resources on the internet with pictures and the whole 9 yards, so you have all the advantages. Please try to refute one word from any of my posts. :0) Eventually I will have the opportunity to make some real posts here and you are welcome to come behind and write counterproposals using anything on earth you consider ‘credible evidence.’

GL in the debates,

Terral

 

[BenBurch]

Terral?

I know people who picked up body parts and aircraft seats at the Pentagon, so I think you need to re-think your whole point of view.

(I'm being nice because you are new and learning.)

-Ben