I know what happens in 2012.

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Now, what has me interested is you said three other planes were missing. That leaves two unaccounted for.

Well Rusty, when my brother recieved that phone call, he was told about the first plane hitting the WTC. At that point that had been the only plane that had crashed. The 2nd plane was still inbound to NYC - so it hadn't hit the other tower just yet. The remaining planes unaccounted for, were the third jet that slammed into the Pentagon in Wash D.C, and the last jet, which augered a hole in the ground in Pennsylvania.

I'm with you - when those buildings fell that was an incredible sight for sure. There wasn't a peep out of any of us who were sitting there watching the TV in that conference room. Any thoughts of going to war we might of had at that point - were premature. I think most all of us were in deep shock.

My input to Titorite:

Dude I feel your frustration and anger here. Its very easy to see why the conspiracy theorists have had a field day with this incident. Reliable information was - and still is hard to come by. I do believe we are not being told the whole story about 9/11 - and most likely never will be - but the evedence of what happened at WTC to the twin towers stands pretty much on its own merits. It was massive structural failure in each that brought them both down. I'm no Engineer, but it doesn't take a rocket scientist to see that RMT and Indy with their backgrounds - are absolutely correct.

If there is a kind of conspiracy of sorts, then it must of transpired in the months, weeks and days that led up to 9/11 and after. Where most of us could understand going after Osama Bin Laden in afghanistan - I don't think anyone of us still buys the BS we've been fed for going into Iraq and deposing Saddam Hussein. The sight of G.W.Bush on TV makes me want to puke! As far as I'm concerned he, Dick Cheney and Donald Rumbsfeld are all War Criminals (my opinions only.)
 
"I have been reading these posts since I joined here and I would like to add my two cents. I do think that 911 was an inside job or at least they let it happen. I have felt this way since day one. I remember the day all to well I was in the army at the time. A week prior to the attacks all military installations were being closed to the public. I thought this was strange because when I joined all military posts were opened. Whats more strange all of them closed on the same day 8/31/01.

I asked the Captain of my unit why were all the bases being closed he said specifically because of terrorism. I was wondering why in world are we going to such extremes for terrorism as far as I knew at the time terrorism wasnt such a big issue. Then a week and half later 911 happens. This to me was no coincedence somebody somewhere knew something. From that day on Ive investigated just about everything Ive heard concerning our government.
"

Now here above is an example of what I mean. Terrorism was the last thing any of us civilians were thinking about. I know I wasn't. Thanks for sharing this with us, ssgsidious. So then - what did our Government really know before 9/11, and what is it they still aren't telling us about it now?

9/11 really does have all the earmarks of being an inside job. In comparison - its almost like what transpired in 1940 - a year prior to the bombing of Pearl Harbor. There was no surprise attack... despite the immortal "this day will live in imfamy " retoric - our Goverment already knew there was a possibility existing the Japaniese would strike us in Hawaii - well in advance of Dec 1941.

Pres. Roosevelt set some things into motion - which led to Pearl Harbor and our entrance into WW II. Seems to me it was a major trade embargo of raw materials, and oil - it was something along those lines. We'd supposedly stopped shippments to the Japaniese - in retaliation for their entering into axial alliance with the Italians and the Germans. As a result Japan declared war on the United States. Even though we entered into talks with them - we were clearly intent on entering the war.
 
the third jet that slammed into the Pentagon in Wash D.C
I wanted to avoid mentioning that as this is the only 'crash' that I truly believe to be a dud.

No wings at the crash site. No real plane wreckage. FBI involvement of confisicating videos that would have shown such a craft on such a flight path. This isn't forgetting it managed to punch through many, many walls without appearing to have even crumpled (which would have slowed it down to the point of being noticable as part of the wreckage). Only minor scorch marks outside. If you think 9/11 was fishy, this one is the damn fish shop.


Now, obviously the object that hit into the building was rounded. It didn't have any wings (as none were found). It was a small object (small amount of wreckage). I doubt it's some comical misfiring giant ball bearing. The tip must be rounded for it to withstand impact for that point. More interestingly, it immediately explodes on contact with the wall, now, I don't know about you, but I didn't figure the cockpit of an airliner to be laden with explosive materials.

More interestingly, the hole punched out the other end is much smaller. Had the cockpit really suffered some serious 'explode on impact' effect, then quite frankly, it wouldn't have punched a hole through 6 walls, leave a small hole at the end AND maintain a straight line.

It's not a typical missle if one was used. Missles explode on impact. It would not have punched through 6 walls. However, it may be, as being casually suggested by some sites, a multi-layered missle. As in, the explosion penetrates the wall, then a smaller part (or the rear end of the craft) continues forward. This would explain the smaller hole on the other end.

The craft also generated a high-pitched sound. Airliners generate low pitch sounds. Doodle-bugs from World War II were well known for their high-pitched noise. The rotor blades found at the scene also do not suit Airlines. However, the rotors would suggest a light aircraft was used. However, the control neccessary to get low and close enough, at such high speed to avoid interception would imply it's entirely automated. Not even remoted controlled. We're talking a pre-planned strike with the route fully set-out. No Airliner could pull it off.

Perhaps, it may be, the fourth aircraft you speak of is, in actual fact, the third aircraft, with the fourth being made-up to cover up for the fact that a missle strike on the US pentagon would serve to be an embarassing tribute. Where the missle came from, what designs it was made of are another question entirely.
 
Okay. i'll give ya the crash at the pentagon; even the photos and video coverage of that, has always kind of bothered me too as well. I guess they've expected us all to buy into and believe a plane the size of a 757 hit the building going so fast that it squeezed through a perfectly circular hole wings and all. There was no evidence of wing damage to the building, plane debris, or even more telling - no damage of the lawn leading up to the wall on that side of the building. As low as that plane was flying to the ground... it should of hit the ground and slid into the building. Guy had to be one hell of a pilot not to destroy any vehicles etc.

I've reviewed "Loose Change" several times online. I have paid particular attention to the pentagon part - where they talk about the lone Engine turbine they "recovered from the wreckage."

How it was way too small to be a component in a 757 engine. I've stood inside a the front of a jet engine myself. You ever wonder what was inside that big blue box on the TV they brought out later on? I sure have. So for the moment we'll call it a "Collision of some type." Even the footage from the security camera that was eventually released; its hard to say what impacted that wall.

So what we have now - out of "four" crash sites theres really only 2 which appear to have been definite plane hits. And we have one that was likely caused by an aircraft (there didn't seem to be a lot of wreckage in PA that resembled a plane crash either.)
 
I believe I may have been looking at both cases in the wrong way. I've been trying to look at what both acts are trying to *cause* politically, when the answer as to what they were was staring me in the face when I was looking over the Pentagon.

Think about it. What's the one useful thing that you could possibly have from a plane, aside from the plane itself? Given planes are readily accessible, I doubt it's the plane, obviously. It's not the cargo, as two planes were destroyed and it's one hell of a mess to spread over four planes without being noticed. The only other possible item of interest on the plane itself would be the people.

Two planes are destroyed. Two planes missing. Elimination of a group of people in the first instance, and the disappearence in the second. The new missle type technology (dual explosive warhead) is American in nature. It's been staged, good sirs. I bet, if we were to uncover the records of who was onboard those planes on that day, those who were killed in the twin towers, and those reportedly lost in the Pentagon and we were to look over their records, we would probably unveil a new kind of mystery.

The game is afoot!
 
The pentagon...Something else to notice is when you look at all the right after impact photos you'll note many light poles, upright, intact, not cliped by a plane. With so many video camera aimed at the pentagon you would think the government would want to end an debate by releaseing more video of the impact spesificly the civilian video...

Then thier is WTC7 which fell for inconclusive reasons according to the 911 commision.

And those are two red flags that should draw anyones attention to investigate more,especialy the intellectual like RMT and indazona. With thier backrounds they really aught to know better. Instead they promote the offical version hook, line, and sinker. One can only be lead to believe that some people, no matter how well educated, are incappable of accepting a painful truth. 911 is not like the unsupriseing sneak attack but more like the Gulf of Tulkin event or Hitlers Riechstag.

One does not need to know every single detail about 911 to understand that 4 planes did not bring down 3 and half buildings. Four planes crashed, yes, but what brought down those buildings was something else other than plane impacts and fire.
 
Back to my area of expertise. Specifically, airplane crashes and the Pentagon. I have served on many aircraft accident investigations, the most notable and pertinent to the Pentagon (similarity) was the MD-11 crash in the ocean off Halifax, Nova Scotia. That airplane hit the water (not a reinforced concrete building such as the Pentagon) and not only were the wings sheared off when it hit the water, but the largest piece recovered from that crash was also just the jet engine fan disk.

I am sorry to have to tell you folks this, and I am quite sure titorite will try to refute it and pretend to have more knowledge than I, but you are making assumptions about how airplanes are "supposed to crash" into reinforced concrete buildings that are just not viable. Here is a video of a Phantom F-4 fighter hitting a concrete wall at 500 mph. Note that the airplane DISINTEGRATES!

http://www.youtube.com/watch?v=SWm5rU7oVn4

Now, some FACTS about fighter vs. commercial airplane designs which can be verfied by studying the Federal Aviation Regulations: A commercial airplane only needs to be designed to withstand 2.5 times the acceleration of gravity (i.e. "2.5 gees"). However, a fighter has to be able to pull up to 9 gees without bending or breaking its wings. So now... if a FIGHTER like the F-4, designed to handle up to 9 gees disintigrates when it hits a cement wall, what do you think is going to happen to a commercial airplane, with MUCH longer wings which are only designed to handle 2.5 gees? The answer has been clearly modeled, and it is that the wings sheared off and essentially wrapped back upon the fuselage as it (the fuselage) created the hole in the Pentagon. And of course people will then say "why do we see holes for wings in the WTC?" Because the outer steel cladding of the WTC were not reinforced with concrete like the Pentagon! The concrete walls of the Pentagon were much heavier, thus much more mass, thus provided a much greater resistance against the wings, causing them to shear off. This also speaks to the SHEAR STRESS and SHEAR MODULUS that Darby just mentioned in a recent discussion with Indazona. ALL METALS have lower shear stresses for failure than they do normal stresses for failure. Metals fail in shear much sooner than they fail in tension or compression.

Finally, you can't expect to use witnesses at ground zero who "said they heard explosions" and then ignore WELL OVER 20 PEOPLE who witnessed and identified the 757 that was approaching the Pentagon before it struck. How do you explain that away??? (Don't tell me.... "they must be in on the conspiracy, so they must be lying!"...right?)

You folks can make all the statements you want about how "I am buying the official story hook line and sinker", and disparage me in plenty of ways. But that does not change the fact that I have been trained and possess detailed scientific knowledge about these things (airplane crashes) that you can only speculate about. And I might add you are speculating incorrectly based on how you think physics works, rather than how it really works. Ruthless has come to see that, but I can see some of you will never come to see that or admit it. That is not my problem. You are only fooling yourself.

I am quite sure if you ask Darby about what I am talking about here he will also agree and validate what I am saying. But then again, you believe what you wish to believe. That does not make it right, and that is why people like myself, with expertise like myself, get paid to perform such analyses... because we possess detailed knowledge that average folks do not. Which begs the analogy:

Would you feel comfortable operating on yourself, or would you prefer to allow a physician to do so? It is a valid analogy to what you are talking about, because of the similarity of depth of technical information that an engineer has that you folks simply think you can reason through with limited knowledge of physics. Brain surgery and engineering analysis are a lot closer in difficulty than you might think.

RMT
 
How does a 757, constructed from lightweight aluminum, penetrate over 9 feet of steel reinforced concrete?

That fighter jet certianly made no impact on the concrete at youtube...

What gives?

Explaination RMT?
 
"The pentagon...Something else to notice is when you look at all the right after impact photos you'll note many light poles, upright, intact, not cliped by a plane. With so many video camera aimed at the pentagon you would think the government would want to end an debate by releaseing more video of the impact spesificly the civilian video..."

Say... you remember the footage that was caught by a lot security camera on the impact side of building (pentagon) Theres a site online - I was at earlier this afternoon. The person who analysed the photos taken from that camera, feels it was altered. Said a frame was missing - where you obviously would have been able to make out what struck the building a litle more clearly.

http://www.thewebfairy.com/911/pentagon/second_frame.htm

http://0911.site.voila.fr/ << this 2nd site contains a 3D model of pentagon crash. Also, here are measurements.
 
Hello Mr. Darby:

Back to Young's Modulus. For carbon steel it's on the order of 205-210 GPa (giga-Pascals). We talked about shearing forces acting on the columns. What about the shear modulus of the same steel? Is the shear modulus the same or is it significantly less than the Young Modulus at the same temperature? (In "English" for the non-engineers : Is the steel column more likely to bear up the weight from above if the weight is evenly distributed straight down the length of the column or is it more likely to hold up the weight above if the force is "slicing" at an angle through the column for a considerable amount of time and at a moderately high temperature?)

Wow, you're throwing me the softball questions, eh? /ttiforum/images/graemlins/smile.gif No need to set me up for the answer you already know!
But of course you are correct that the shear modulus is much lower than the tensile or compressive stress modulus for virtually all metals. The shear modulus for carbon steel is only 11.5 million lb-inch^2, as compared to the equivalent units for the values you define above in GPa for the compressive Young's modulus (29 million lb-inch^2). You can find these at the following link:

http://www.engineersedge.com/manufacturing_spec/average_properties_structural_materials.htm

Given that a ~150 t mass struck the structure with a velocity of ~700 ft/sec is it possible that the carbon steel suffered any high-velocity impact thermal shock effects - resulting in a degradation of the Young Modulus index for a given temperature? (Again, in English for the non-engineers: if a huge masss slams into the building at high velocity does the shockwave that rattles through the structure knock the steel molucules loose from each other and make it a lot weaker than it was before the impact?)

Another very good point, Mr. Darby. Certainly there is an effect on Young's Modulus due to impact. However, in my professional opinion it is at least an order of magnitude smaller than both the heating effects of the fire and any plastic deformation experienced by columns that were not completely severed. So yes, it had a degrading effect, albeit a small one. Good to point out all the sources of weakness.

And don't you worry, Mr. titorite, I will be back to deal some more with you. You have again exhibited your ignorance and that you, yourself, have been ignoring evidence that is clearly available. And I also find it a bit self-serving that you so easily dismissed Mr. Darby's excellent presentation on fuel-air mixtures, and how that jet fuel could not possibly have all burned off in a fireball without bringing down the towers. Your response was, once again, ignoring technical facts that don't fit your beliefs. It exhibits your own hypocrisy given the tag line you wish everyone to think is true about yourself.
 
How does a 757, constructed from lightweight aluminum, penetrate over 9 feet of steel reinforced concrete?

That fighter jet certianly made no impact on the concrete at youtube...
Are you claiming the F-4 fighter did not penetrate that concrete? (I'd like a direct answer to that question, please). Because if that is what you are claiming ("certianly made no impact"), it seems you are coming to a conclusion when no evidence was present. There was no "after" photo showing what the wall looked like after the impact was over... now was there? (I'd like a direct answer to that question as well).

RMT
 
One thing I'm curious about knowing - or trying to understand, RMT. After viewing the F-4 footage in the link you posted above - is why the right wing (clearly visible in the footage of the jet from RHS on impact) saws through the test block, rather than shears off or folds back onto the fusealage.
 
@RainmanTime

Your post is certainly extremely over-defensive good sir. We are only trying to establish what occured here, not tear each other to shreads. Sorry, I have my Sherlock hat on.

Now, what proposes to me that such an aircraft is not an airliner are two things.

One, the aircraft would have to fly low. Now, your witness reports claimed it flew overhead, however, if this was such the case, it would not have been able to form a direct impact on the pentagon. At least, had it dived down out of the sky, the pentration point would have not been at the bottom of the building, and the plane would have crumpled into the ground.

Alas, it has not crumpled into the ground, not damaged the building at an angle. The craft was therefore flying low.

Now, as you know, airliners are a large peice of aircraft. Now, I am no pilot, but, I doubt the craft is able to fly at high speed, low to the ground, without hitting any objects or obstructions, given it is a large, noticable object. Remember, this conflicts with the reports of the eyewitnesses who claim to have seen it flying overhead, which would mean it's approach angle is wrong.

This is not forgetting that no Airline pilot would be trained to push a craft to such limits, and nor would a hijacker. If it had hit a single obstuction, it would have probably veered off-course and smashed. This makes for an interesting ploy that the craft lost it's wings earlier on... how do you suppose an aircraft could continue a direct, low-level flight towards the pentagon minus one, or two, wings? If it had lost the wings, surely the jet engines (attached to the wings) would not have been found at the scene? Is it not also curious the jet engine found at the scene could not support such an aircraft in the first instance. This is not forgetting the wreckage at the scene is too small scale to have been an airliner... I don't suppose you could explain where the large proportion went... including the wings?

The problem is, you make an assumption. You assume the eyewitnesses tell the truth, and the aircraft they saw continued towards the pentagon and smashed into it. Since we have no video evidence, and any evidence, such as this is relatively suspicious the frame showing the aircrafts transition is missing, we cannot make any real stable assumptions of what went on, aside from the provable facts of the case.

The outer, steel concrete wall had been penetrated.
The inter, steel concrete wall had been penetrated in a straight line direct from the penetration on the outter steel concrete wall, through several steel concrete walls.
The explosion, disruption or other such destruction occured at where the aircraft's point hit.
There was minimal damage to the lawn. I think it is safe to say the groundskeeper would be at least been pleased.
A rotor was retrieved was for a smaller aircraft.
Little debris was left at the scene.

Now, the rotor and lack of debris suggest the aircraft was small. The lack of damage around the scene suggests it was directed, something all planes do not do when they crash. The direct line suggests the craft was flying low, something any airplane, and pilot, would have great difficulty doing - do not forget the point of entry was almost at ground level. The level of penetration suggests the craft was designed for such a purpose, or was at least stronger than the standard type of aircraft. The most damaging part of an airplane is it's fuel tank and engines, which happens to be contained in the wings. The very wings missing from the scene. So why had the plane exploded?

Do not forget, when the airliners crashed into 9/11, a non-reinforced building, it only got roughly half way in. Now, imagine what the airline would do if it went into a wide-spread, low-down ground building which is reinforced.

What you are trained in, regardless of profession, does not make you the sole bearer of the facts, remember this as you suggest to others to get their theories peer-reviewed.
 
One thing I'm curious about knowing - or trying to understand, RMT. After viewing the F-4 footage in the link you posted above - is why the right wing (clearly visible in the footage of the jet from RHS on impact) saws through the test block, rather than shears off or folds back onto the fusealage.

First, as I explained above a fighter (including & especially its wing) is designed to over 3.5 times the load limits that a commercial airplane is. Second, the wings on a fighter are much shorter than a commercial airplane's wings (and so this magnifies their already over-designed strength). But finally, are you certain (or are you assuming) that the wing is remaining intact, instead of simply the tip portion of the wing which is not striking the concrete is actually shearing off right at the concrete? The evidence does not suggest either way, but if it did shear off at the wingtip, the high momentum of the wingtip would carry it forward just as you see in the video. It is too bad the video does not continue beyond this point, as this would solve this question.

RMT
 
Your post is certainly extremely over-defensive good sir. We are only trying to establish what occured here

That is what you may think you are doing. What I am doing is dispelling analysis and conclusions that I know are based on incomplete or inaccurate assumptions.

The problem is, you make an assumption.

The problem is, your reply is chock-full of assumptions, with many of them being uninformed and inaccurate assumptions that you may not even believe you are making. Let me show you:

One, the aircraft would have to fly low. Now, your witness reports claimed it flew overhead, however, if this was such the case, it would not have been able to form a direct impact on the pentagon.

This interpretation has explicit assumptions that you are attributing that the witness did not state, namely that the airplane remained overhead for its entire flight path. It also assumes that an airplane cannot fly low and still be over a person's head. Both are incorrect assumptions.

Now, as you know, airliners are a large peice of aircraft. Now, I am no pilot, but, I doubt the craft is able to fly at high speed, low to the ground, without hitting any objects or obstructions, given it is a large, noticable object.

That is an extremely uninformed assumption, and you even tell us why: You are not a pilot. In fact, it actually is quite easy to fly that low to the ground due to something called "aerodynamic ground effect". This effect actually increases the lift on the airplane due to the "cushion of air" it is riding upon between itself and the ground. In addition, this ground effect artificially enhances the pitch stability of the airplane, making it easier to maintain a constant altitude than when you are "up and away". Finally, the other thing that makes your assumption incorrect is that myself, and many other engineers and pilots, have actually flown much larger airplanes than a 757 (like an MD-11) at altitudes of 20, 10, and even 5 feet above the ground during flight tests. So to recap, this assumption you make is not based on facts and/or data about the stability and control characteristics of large transport aircraft.

This is not forgetting that no Airline pilot would be trained to push a craft to such limits, and nor would a hijacker.

Those are blatant assumptions that you have no means to backup. Moreover, if a hijacker's express mission was to maximize damage by hitting the Pentagon, don't you think he would HAVE to be trained to fly that profile? It only stands to reason if you want someone to do something, with a high degree of assurance, that you would wish to train them. So the logic in the second part of your assumption is terribly flawed.

This makes for an interesting ploy that the craft lost it's wings earlier on... how do you suppose an aircraft could continue a direct, low-level flight towards the pentagon minus one, or two, wings?

You assume it lost its wings but have no evidence that this is so.

This is not forgetting the wreckage at the scene is too small scale to have been an airliner...

This is an assumption based on what you believe to be the fracture mechanics of airplanes hitting concrete buildings at high speed. The assumption is incorrect, and the F-4 video proves it is incorrect.

I don't suppose you could explain where the large proportion went... including the wings?

I already did. See above.

You assume the eyewitnesses tell the truth

And the same assumption is made in NYC by conspiracy theorists who claim witnesses told the truth about hearing "explosions" or even worse "bombs". You can't have it both ways. Either you accept all their testimony and qualify the parts you use, or you accept none of it.

A rotor was retrieved was for a smaller aircraft.

That is either an incorrect assumption or based on false facts. The following page clearly shows where the identified parts came from on a 757 engine:

http://www.911myths.com/html/757_wreckage.html

Little debris was left at the scene.

Incorrect assumption that does not take into account the clear photographic evidence in the link above. Have you researched the American Airlines livery (external airplane color scheme)? It is polished aluminum with red, white, and blue trim around the fuselage. Precisely the colorings we see in this photo:
db_Pentagon_Debris_91.jpg

Not to mention this photo:
db_Pentagon_Debris_171.jpg


In this photo above, if you look in the background you can even see the red letter "c" from the airline's name "American" which appears on the side of the airplane, as seen in this photo:
990201b.jpg


So you cannot deny that this evidence pretty much trashes your assumptions. Clearly that red "c" is a match. How do you explain that away?

The lack of damage around the scene suggests it was directed, something all planes do not do when they crash.

One assumption of what it suggest, and not the most likely one when you understand fracture mechanics of an airplane flying into concrete at 500 mph.

The direct line suggests the craft was flying low, something any airplane, and pilot, would have great difficulty doing

You said you were not a pilot. So for you to make this assumption is disingenuous. You cannot and do not know, and as I explained about ground effect above, this assumption is wrong.

What you are trained in, regardless of profession, does not make you the sole bearer of the facts
True enough, but what my profession and training does make me is more qualified than folks like yourself to arrive at conclusions about aircraft accidents. As I have shown above, your assumptions about these technical issues are often incorrect, and by thinking you know something that you are not trained in, such assumptions can (and often do) lead to incorrect conclusions.

remember this as you suggest to others to get their theories peer-reviewed.

Yes, and the operative word here is "peer". You are not qualified to review the analysis I have presented to counter your assumptions, therefore any attempt by you to show my analysis is incorrect would be futile. However, another aerospace engineer trained in aircraft and aircraft accidents (i.e. my peer) could, indeed, review my analysis for accuracy.

RMT
 
Thanks for your reply RMT. It IS a shame there wasn't more to the film.

To pose a hypothetical for a moment: I wonder what would have occured had that block been significantly wider than the planes 11.7m (38' 4-1/2") wingspan - using a solid block wall that was say 1/2 the width, but same thickness - as the section that was impacted at the pentagon?

One other thing caught my eye, and that was the amount of compression the fueslage of the plane underwent in forward momentum, before finally bursting through the other side of that block.
I doubt there was much left of the target anyways to be evaluated afterwards - hehe.
So much of that cement was displaced @ POI - it exploded upward and outward by the time the tail section had followed thru and disappeared.

I'd like to relate an interesting but true story. My dad was a pilot in the USAF - stationed in Europe, flying Martin B-57's during the 1950's. he dropped by for coffee this morning, and after showing him the footage of the Phantom meeting Cement block, we discussedg some things I wasn't sure about in the video - and neither one of us could come to a conclusion. Dads problem with it, like mine - was the size of the block in relation to the wingspan of the fighter - assuming the hit was dead center on the cement block.

He told me about a crash that happened at the base where he was stationed. It had occurred during a take off after a rainstorm. The base had a 9,000 ft runway, but 1/2 of that was being resurfaced at the time - so inbound and out flights only had about 4500 ft available to use.

This wouldn't have been a problem for a B-57, according to him, as the plane only required 4000 ft to take off. Anyway, the base also had several 9'ft high piles of PSP (Punched Steel Plate? - L x W x thickness form factors unknown - used for temp runways.) stacked up in storage area about 20 deg's off to one side of the runway. The guy took off and just got airborne, when he discovered a problem with an engine. The pilot didn't have alot of seat time in the plane, according to dad, and probably didn't realize a B-57 could fly in an emergency on one engine. His mistake was that he decided to try and land the plane. Once the plane touched down - the pilot realized he didn't have enough runway left to stop.

In a panic, he somehow veered the plane off the runway and into the path of those stacks of PSP.
At this point, dad said the plane was going approx 100+ mph. At POI - the tail on the Plane sheared off, and what was left of fuselage got stuffed into the the 9' high stacks of PSP and the momentum shoved the piles about 4ft. I realize its not the same thing as hitting cement at 500 mph. But -I was surprised to hear there was wreckage and human remains.
 
Hello JL (if you don't mind me shortening your handle):

To pose a hypothetical for a moment: I wonder what would have occured had that block been significantly wider than the planes 11.7m (38' 4-1/2") wingspan - using a solid block wall that was say 1/2 the width, but same thickness - as the section that was impacted at the pentagon?

I am not clear exactly what you are saying... you mean the F-4 hitting a larger block, but the thickness of the Pentagon? Hard to say without modeling it (as a minimum). But as I mentioned earlier, due to the design strength of the F-4 wing it would put up a much greater resistance to the concrete than a commercial aircraft.

At this point, dad said the plane was going approx 100+ mph. At POI - the tail on the Plane sheared off, and what was left of fuselage got stuffed into the the 9' high stacks of PSP and the momentum shoved the piles about 4ft. I realize its not the same thing as hitting cement at 500 mph. But -I was surprised to hear there was wreckage and human remains.

There are two very important "embedded" facts in what you have stated here that can help folks understand the mechanics of impacts such as this. I'd like to highlight them, since it seems you are more interested in understanding than coming to conclusions.

1) Compliance of the stationary body. In your story the PSP were apparantly not secured to the ground where they were stacked. This is evident, for you report that the airplane's impact moved the stack. In the case of the WTC, Pentagon, and PA aircraft the bodies they hit either were secured to ground, or was the ground itself (PA). There is going to be a lot more damage to the airplane when the object it hits has a lower compliance (due to being "grounded"). It should simply stand to reason, but the equations of momentum exchange even bear this out as a fact. A body that is not "grounded" to a larger body, when impacted, will begin to move in the same direction as the body that strikes it. As Darby pointed out in an earlier post, in a "perfectly elastic collision" the stationary body that was struck would "absorb" exactly half of the moving body's velocity. But airplanes and stacks of steel are far from "perfectly elastic" collisions. :eek:

2) A large force beyond just the impact forces, due to deceleration. Many folks without training in physics would assume that the only forces to cause damage to the airplane would be those resulting from airplane-to-object contact (i.e. the impact forces). However, since "F=ma" there is another force that comes into play simply as a result of the mass of the airplane decelerating at a high rate due to the impact. This explains why even though the nose of the airplane in your story impacted the PSP before the tail, the tail still sheared off at the point of impact.

Thank you for sharing that story, as it helped me to make yet another point that such analysis is not as "intuitive" as folks without a background in physics may wish to believe.

RMT
 
JustLurking,

You'll be surprised at the various occupations or employment info on the passengers [of AA Flt 77].

My friend, why should we be surprised at the occupation/employers (related to the federal government) of people flying out of Washington, DC?
 
YES RMT I am claiming that the fighter jet in the youtube video did not travel all the way through the concrete wall it smashed.

So again I ask, how did a 757 , made from lightweight aluminum, penatrate over 9 feet of steel reinforced concrete?

You can't have it both ways RMT. That you tube video shown with crystal clarity that the fighter jet could not go through on concrete wall. How did the commercal air bus travel through several?
 
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