Debunked: Demolition “squib” is visible at top of WTC North Tower before Flight 11 crash

On an aircraft with wing-mounted engines, these connections are strong enough to allow the engines to quickly accelerate the fully loaded fuselage to take-off speed.

The 767 wing attaches over ~20% of the length of the fuselage. You'll be hard pressed to find a household item with a bigger handle.
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Right, but wouldn't a longer handle be easier to tear off or come loose than a shorter handle if that handle impacted another solid, flat surface that is oriented normally to the length of the handle?
I assure you they're there.
This was a "rough landing".
I assume they are under water but the plane mostly impacted the water such that the broad width underside of the wings was one of the first part of the wings to impact the water, which differs from how the narrow front sides of the wings were some of the first parts of the wings to impact the towers. Also in the "rough landing", the plane would be impacting a surface at a shallow angle, whereas in 9/11 the planes were oriented normal to the building face.

In any case, with the "rough landing", a large area of the underside of the wing would be impacting the water at once, meaning the force of the landing would be spread across a wide area of the wing at a slower rate, lessening the impulse and damage to the wing.

Whereas in impacts where the plane is angled and either a portion of the wing impacts the ground or hits a building head on, the force is spread over a narrower area and at a faster rate and so there is more damage to the impacted portion of the wing that is able to be done.
 
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Well like the window glass is the weak point in a building, the wings are a less sturdy piece of an airplane and the weak point in an airplane (wings seem like the first to shear off an aircraft in any crash or extreme turbulence), so I don't see why it would be unreasonable to assume that if the airplane was traveling at a slower speed, the wings would be sheared off during impact and not fully make it into the building, while the front part of the fuselage would still make it past the exterior columns.
Note that you both suppose the wing would shear off.
So wouldn't it follow that in a lower speed plane crash (like was envisioned when the towers were originally constructed), at least a significant portion of the wings farther away radially from the fuselage would be sheared off and not enter the building?
The fact that the wing might detach from the fuselage says nothing about its ability to enter the building on its own.

We've established that the weight of the fuel in the wing tanks provides the wings with a lot of inertia, while the low profile of the wing concentrates the pressure on the front edge, like a knife.

I suggest to not draw conclusions without a thorough analysis that uses actual numbers and physical laws.
 
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Note that you both suppose the wing would shear off.

The fact that the wing might detach from the fuselage says nothing about its ability to enter the building on its own.

We've established that tje weight of the fuel in the wing tanks provides the wings with a lot of inertia, while the low profile of the wing concentrates the pressure on the front edge, like a knife.
Okay, I can see that even torn up and damaged and traveling at a slower speed, the wings would still be to enter the building and still provide a broad cutting motion.
I suggest to not draw conclusions without a thorough analysis that uses actual numbers and physical laws.
Okay, I was going by visual observations of the incident and similar such plane crash incidents to see what occurs in such situations. However, I see that anecdotal evidence and expectations of what occurred in previous crashes on its own isn't enough to explain apparent discrepancies in what occurs in some plane crashes.
 
I was going by visual observations of the incident and similar such plane crash incidents to see what occurs in such situations.
Visual observation: wing-shaped holes in the outsides of the WTC towers, right?
G11.jpg
What "similar plane crashes" are you referring to? I didn't see you cite any?
I did provide you with a picture of a wing that impacted an obstacle at take-off.


expectations
Expectations only count if you actually have experience.
You, on the other hand, expect wings to detach "in any severe turbulence, rough landing".
 
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Right, but wouldn't a longer handle be easier to tear off or come loose than a shorter handle if that handle impacted another solid, flat surface that is oriented normally to the length of the handle?
You specifically asserted "the wings would be sheared off". I don't see how the length makes a difference concerning the resistance to shearing?

My point was that the attachment of the wing to the fuselage is quite wide in the direction of the motion and so provides good shear resistance.
 
Visual observation: wing-shaped holes in the outsides of the WTC towers, right?
G11.jpg
Yes and I have no doubt that at the speeds the planes were traveling at, the most of the wings would have penetrated the exterior facade of the building. I intially had some doubts that similar would occur if the plane was traveling much slower, but the continuum explanation about how more and more of the wings would penetrate the building in faster speed crashes cleared up that confusion I had.

I had also had confusion about airplane wings coming off first in rough turbulence, but that appears to be more a case of bad maintenance, as apparently even in extreme turbulence, airplane wings shouldn't come loose or snap off.
https://www.travelandleisure.com/travel-news/can-airplane-wings-snap-off
What "similar plane crashes" are you referring to? I didn't see you cite any?
I don't know of many other similar plane crashes into buildings other than the plane crash into the Empire State Building, although that was a much smaller plane.

By "similar plane crashes", I meant the type of plane crashes where the wings impact the ground first (such as the plane crashes that occur at air shows) and get torn off. My intent in mentioning similar plane crashes was to say that in similar situations where a plane is crashing (not just having a "rough landing"), I have seen that the wings are some of the first parts of the plane to become loose and fall apart, compared to the fuselage, making me think that the wings are very vulnerable to coming loose first in any plane crash.
You specifically asserted "the wings would be sheared off". I don't see how the length makes a difference concerning the resistance to shearing?
Isn't a longer handle more easily able to be bent and snapped off than a shorter handle if it impacts a solid surface oriented at a 90 degree angle? The longer handle in this case being the wing and the solid surface oriented at a 90 degree angle being the building.
My point was that the attachment of the wing to the fuselage is quite wide in the direction of the motion and so provides good shear resistance.
If the attachment of the wing to the fuselage is quite wide that would make sense that it provides better resistance than a smaller, less wide attachment that would more easily come loose from damage.
 
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I don't know of many other similar plane crashes into buildings other than the plane crash into the Empire State Building, although that was a much smaller plane.
What happened to its wings?

By "similar plane crashes", I meant the type of plane crashes where the wings impact the ground first (such as the plane crashes that occur at air shows) and get torn off.
But when an aircraft flies into a building, the nose impacts first? Quite a different situation.
And with a swept wing, the wing tip impacts the building last, while it is often the first/only part to impact the ground in the type of incident you envision. And even then, an airliner wing tip making ground contact is usually not catastrophic; wing tip strikes are a more common occurrence than you probably expect.
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I only remember one passenger jet crashing at an air show, were there more?
 
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What happened to its wings?
I assume they were severed from the fuselage as one engine reportedly fell down an elevator shaft and the other engine pierced the opposite side of the building and traveled up to 900 feet away from the building, with a part of a wing reportedly flying out the opposite side as well.
http://www.aerospaceweb.org/question/history/q0311.shtml
Other heavy wreckage, including the landing gear, also caused damage to the Empire State and nearby buildings while Stan Lomax reportedly saw part of a wing catapulting towards Madison Avenue.
But when an aircraft flies into a building, the nose impacts first? Quite a different situation.
I can kind of understand that, the wing would be shaken but remain in place unlike the leading edge of the wing impacted the exterior columns, at which point the wings would probably start to come loose from the fuselage but continue traveling into the building.
And with a swept wing, the wing tip impacts the building last, while it is often the first/only part to impact the ground in the type of incident you envision. And even then, an airliner wing tip making ground contact is usually not catastrophic; wing tip strikes are a more common occurrence than you probably expect.
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I only remember one passenger jet crashing at an air show, were there more?
I can link some, although the planes were often not as large as 767s or commercial airliners.
The first link isn't from an air show, but shows a wing coming off a large plane and the plane crashing.
The second link is the wing coming off a small plane when it crashes at an airshow.



There are reports of a plane losing its wingtip following a crash at a Paris Air Show in 2011
https://www.bbc.com/news/business-13839955
Airbus' appearance at the Paris Air Show has been blighted by misfortune, with two key planes damaged.
The wing tip of its demonstration A380 superjumbo struck a building at Le Bourguet airport venue during taxiing.
Gearbox problems have stopped its A400M military transporter from performing a scheduled aerial display, although it will still take part in a fly-past.
There is also the case of a hijacked plane in 1996 crashing into water where the wing appears to have come loose
https://aviation-safety.net/database/record.php?id=19961123-0
By this time the flight crew had been left alone to assume control. They turned the aircraft to the left in order to parallel the waves. However, the aircraft brushed the water in a left-wing-low attitude. It was then held straight and level after which it broke into four sections and came to rest in the sheltered waters 500 m off Le Galawa Beach.

There is also the Mayday airplane crash, where the wing that impacted the ground appears to come off at 33:17 in the following video:

 
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at which point the wings would probably start to come loose from the fuselage
You have failed to show any evidence that supports this assertion.


The first link isn't from an air show, but shows a wing coming off a large plane and the plane crashing.
it exploded in mid-air .... the blast separated the wings from the fuselage
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How is this relevant?


There are reports of a plane losing its wingtip following a crash at a Paris Air Show in 2011
There was no crash at that air show, the wing did not come off, and the damage was superficial:
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Three days after a taxiing prang temporarily grounded it, an Airbus A380 test aircraft was flown at Le Bourget yesterday. "[...] The jet's damaged wingtip had been replaced with one taken from another test A380 in Toulouse.


There is also the case of a hijacked plane in 1996 crashing into water where the wing appears to have come loose
https://aviation-safety.net/database/record.php?id=19961123-0
The wing did not come loose in the ET961 crash. "It was then held straight and level" implies that the wing was still attached, and the picture in the appendix of the accident report proves that.

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There is also the Mayday airplane crash
From the video description: "Shortly after takeoff, an anti-aircraft missile fired on the ground hit the Airbus A300."
The wing was hit, but did not come off.
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where the wing that impacted the ground appears to come off at 33:17 in the following video:
That part of the video depicts the crash of UA 232 at Sioux City.
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The engines were not able to respond to Fitch's commands in time to stop the roll, and the plane impacted the ground with its right wing, spilling fuel, which ignited immediately. The tail section broke off from the force of the impact, and the rest of the aircraft bounced several times, shedding the landing gear and engine nacelles and breaking the fuselage into several main pieces. On the final impact, the right wing was torn off and the main part of the aircraft skidded sideways, rolled over onto its back, and slid to a stop upside-down in a corn field to the right of Runway 22.

Note that the right wing was the last part to break off, and the left wing never did. (And there was no air show.)

I now expect you to apologize.
 
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The eyewitness account of the tail falling onto Liberty Street
A single eyewitness account can be interesting sometimes, but if the tail fell onto Liberty Street, there should be physical evidence that, um, the tail fell onto Liberty Street. And video of the tail falling onto Liberty Street.
 
I can't really see the wings in that picture as they appear to be submerged under the water.
Coincidentally, that plane is in a little aircraft museum here in my home town of Charlotte, which was to be the flight's destination. I can confirm that the wings were still attached after the crash, though later sawed off during the investigation into the accident! They have been reattached for display in the museum. Last time I was out there, the engines, which had also been removed, were there on loan, I am not sure if they are still there or not.
Capture.JPG]

Passengers standing on the wings after the crash.
Capture.JPG

edited to fix an image display issue.
 
I am not sure that I see the point to all of this... We have all established (Including @investigating911) that the planes fully entered the building. Why bother speculating that some of it wouldn't have made it in, if it had been travelling at a slower speed? It wasn't. As far as the eyewitness account goes.... Isn't it possible that he was just speaking in terms or falling parts (in general) and thought that "some must have been plane parts, and the tail is the last part"... so... "the Tail fell must have fallen to the street", and it actually didn't? Was there photo or video evidence of the tail on the street? Is it possible that he same some building wreckage come down that looked like plane parts.. Namely the tail?

I guess I am having trouble trying to understand why this conversation started in the first place....
 
I am not sure that I see the point to all of this... We have all established (Including @investigating911) that the planes fully entered the building. Why bother speculating that some of it wouldn't have made it in, if it had been travelling at a slower speed? It wasn't. As far as the eyewitness account goes.... Isn't it possible that he was just speaking in terms or falling parts (in general) and thought that "some must have been plane parts, and the tail is the last part"... so... "the Tail fell must have fallen to the street", and it actually didn't? Was there photo or video evidence of the tail on the street? Is it possible that he same some building wreckage come down that looked like plane parts.. Namely the tail?

I guess I am having trouble trying to understand why this conversation started in the first place....
Those are my thoughts exactly. The plane crashes were the real deal, not a movie special effect that could have been made to look more realistic. It is pointless to speculate about what should have happened when what did happen is so well documented.

The eyewitness account about mayhem in the South Tower lobby due to burning plane wreckage crashing through the revolving doors on Liberty Street is probably only legendary. To be sure, Liberty Street was littered with building debris, small bits of aircraft wreckage and human remains after the Flight 175 crash but the WTC 2 lobby windows and doors showed no signs of damage as the witness described. Here is only one of several pictures taken by NYPD photographers that show the condition of the WTC 2 lobby facade after both plane crashes.

Roll_4_25_enhanced.jpg
 
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The plane and the building mutually destroyed each other...the momentum carried much of the fuel into the building... lots never made it and burst into flame outside the towers. The most dense heavy bits had so much momentum (engines) that at least one passed through the building and crashed through the opposite facade. The steel which was hit yielded to the massive force of the planes. The fuel tanks were massively destructive. Imagine scores of tons hitting a building at 500mph. The sea can be very destructive to steel structures on ships in storms at much slower speeds.
 
The plane and the building mutually destroyed each other...the momentum carried much of the fuel into the building... lots never made it and burst into flame outside the towers. The most dense heavy bits had so much momentum (engines) that at least one passed through the building and crashed through the opposite facade. The steel which was hit yielded to the massive force of the planes. The fuel tanks were massively destructive. Imagine scores of tons hitting a building at 500mph. The sea can be very destructive to steel structures on ships in storms at much slower speeds.
I am in total agreement about the momentum of the planes and how it carried them through the buildings. However, it was mostly the shearing of bolts holding together the three-story column sections that allowed them to be dislodged so that the aircraft could so easily penetrate the facade. While a few columns actually were severed and/or bent by the impacts, saying that "steel yielded to the massive forces of the planes" reinforces the oft-heard truther meme that the planes seemed to melt through the columns "like a hot knife through butter." With that as an analogy, it's no wonder that, after 20 years, there are still those who think the planes must have been holograms. A far better analogy would be to say the plane slamming into the exterior columns was like a bowling ball knocking away pins.
 
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A far better analogy would be to say the plane slamming into the exterior columns was like a bowling ball knocking away pins.
Agreed. Tho I tend to take a "bigger picture" overview myself -- it's SOP for me from my career background. The usual truther false focus is on the presumption that an aluminium aircraft is "softer" and "weaker" than a steel-framed building. Both assumptions are wrong at the two levels viz (a) actual strength of the two types of metals and (b) relative strength of the two structures. But I tend to focus simply on overwhelming momentum. Even if the weight of aircraft fuel had been contained in a rubber bladder and somehow thrown at the facade of a Twin Tower at aircraft speed >> it would have penetrated.
 
You have failed to show any evidence that supports this assertion.
Other heavy wreckage, including the landing gear, also caused damage to the Empire State and nearby buildings while Stan Lomax reportedly saw part of a wing catapulting towards Madison Avenue.
http://www.aerospaceweb.org/question/history/q0311.shtml
The wings came loose from the fuselage after the plane had impacted the Empire State Building, otherwise who would a part of the wing come catapulting out of the other side of the Empire State Building?
it exploded in mid-air .... the blast separated the wings from the fuselage
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How is this relevant?
It shows that the wings of an airplane can become separate from the fuselage even before a plane has crashed.
There was no crash at that air show, the wing did not come off, and the damage was superficial:
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Three days after a taxiing prang temporarily grounded it, an Airbus A380 test aircraft was flown at Le Bourget yesterday. "[...] The jet's damaged wingtip had been replaced with one taken from another test A380 in Toulouse.



The wing did not come loose in the ET961 crash. "It was then held straight and level" implies that the wing was still attached, and the picture in the appendix of the accident report proves that.

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From the video description: "Shortly after takeoff, an anti-aircraft missile fired on the ground hit the Airbus A300."
The wing was hit, but did not come off.
Article:
Shootdown-10.jpg



That part of the video depicts the crash of UA 232 at Sioux City.
Article:
The engines were not able to respond to Fitch's commands in time to stop the roll, and the plane impacted the ground with its right wing, spilling fuel, which ignited immediately. The tail section broke off from the force of the impact, and the rest of the aircraft bounced several times, shedding the landing gear and engine nacelles and breaking the fuselage into several main pieces. On the final impact, the right wing was torn off and the main part of the aircraft skidded sideways, rolled over onto its back, and slid to a stop upside-down in a corn field to the right of Runway 22.

Note that the right wing was the last part to break off, and the left wing never did. (And there was no air show.)
Okay, it wasn't clear to me that the wings weren't the first parts to break off in those incidents.
I now expect you to apologize.
I apologize for the misunderstanding, I thought part of the wings in the examples you asked me to list had come off or were one of the first parts of the plane to come apart in those incidents.

Those are my thoughts exactly. The plane crashes were the real deal, not a movie special effect that could have been made to look more realistic. It is pointless to speculate about what should have happened when what did happen is so well documented.

The eyewitness account about mayhem in the South Tower lobby due to burning plane wreckage crashing through the revolving doors on Liberty Street is probably only legendary. To be sure, Liberty Street was littered with building debris, small bits of aircraft wreckage and human remains after the Flight 175 crash but the WTC 2 lobby windows and doors showed no signs of damage as the witness described. Here is only one of several pictures taken by NYPD photographers that show the condition of the WTC 2 lobby facade after both plane crashes.

Roll_4_25_enhanced.jpg
If Liberty Street was littered with small bits of aircraft wreckage and human remains after the Flight 175 crash, that would mean that some of the content in the rear and tail end of the aircraft didn't make it into the building, despite still having enough momentum to make it into the building. I don't understand why that would be the case. Perhaps the jetfuel explosions occurring after the plane fully went into the building blew out aircraft and body parts back out of the impact hole and onto Liberty Street?
I am not sure that I see the point to all of this... We have all established (Including @investigating911) that the planes fully entered the building. Why bother speculating that some of it wouldn't have made it in, if it had been travelling at a slower speed? It wasn't. As far as the eyewitness account goes.... Isn't it possible that he was just speaking in terms or falling parts (in general) and thought that "some must have been plane parts, and the tail is the last part"... so... "the Tail fell must have fallen to the street", and it actually didn't? Was there photo or video evidence of the tail on the street? Is it possible that he same some building wreckage come down that looked like plane parts.. Namely the tail?
Because I was wondering whether these "squibs" would be seen had the plane been traveling at a lower speed.

By the eyewitness account, I wouldn't expect the witness to be saying the entire tail section fell, but that a piece of the tail section (about as big as a large piece of luggage and large enough to be visible from the lobby windows) fell down to Liberty Street.
I guess I am having trouble trying to understand why this conversation started in the first place....
Because I was wondering whether these "squibs" would be seen had the plane been traveling at a lower speed such as in the "lost in fog and looking to land" situation. It seems that the "squibs" being seen are related to the passage of a portion of the airplane into the building that blows out building contents and pulverized the concrete and drywall on the impacted floors, with the passage of the rest of the airplane into the building being necessary to blow out this pulverized dust through the windows in floors just above the impact zone in such a demolition squib-like explosion.

A single eyewitness account can be interesting sometimes, but if the tail fell onto Liberty Street, there should be physical evidence that, um, the tail fell onto Liberty Street. And video of the tail falling onto Liberty Street.
There wasn't footage of that occurring because of the lack of cameras on hand ready to record, unlike the present day. And the entire intact tail section probably wouldn't fall onto Liberty Street but a piece of the tail section (presumably identifiable by the logo on the tail section).
 
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The most dense heavy bits had so much momentum (engines) that at least one passed through the building and crashed through the opposite facade.
Similar to what happened in the 1945 Empire State Building crash.

I'd say the engines are actually the part of any big jet that's most likely to separate.
Well like the window glass is the weak point in a building, the wings are a less sturdy piece of an airplane and the weak point in an airplane (wings seem like the first to shear off an aircraft in any crash or extreme turbulence), so I don't see why it would be unreasonable to assume that if the airplane was traveling at a slower speed, the wings would be sheared off during impact and not fully make it into the building, while the front part of the fuselage would still make it past the exterior columns.
Above is your original assertion, below is the evidence you rely on.
http://www.aerospaceweb.org/question/history/q0311.shtml
The wings came loose from the fuselage after the plane had impacted the Empire State Building, otherwise who would a part of the wing come catapulting out of the other side of the Empire State Building?
Even with the slower bomber, a part of the wing "made it" fully through the building.
Your assumption that the wings are the "weak point" and that they would have less power to penetrate the building than the fuselage is not supported by evidence.


I apologize for the misunderstanding, I thought part of the wings in the examples you asked me to list had come off or were one of the first parts of the plane to come apart in those incidents.
There is absolutely nothing in any of the sources you cited that supports the "understanding" that a wing came off as a result of a collision. You failed to undertake even minimal effort to ascertain that your sources actually support your claim, and surreptitiously placed that effort squarely on the reader. This approach to discussion demonstrates a lack of respect for the truth, and a lack of respect for the people you are engaging. Your apology doesn't even begin to cover that.
 
I used the phrase -"mutual destruction" and this is much like two cars crashing... one at high speed and the other parked. The speeding car "enters" the "space" of the parked car.. both are crushed.. there is no passing into like melted butter.
The energy/momentum of elements of the plane ripped the steel in some cases... it was more than shear bolted connections.
 
The energy/momentum of elements of the plane ripped the steel in some cases... it was more than shear bolted connections.
I think part of it is the misconception that the steel columns were "strong" - after all, they supported the skyscraper! The crux is that this strength is directional: they're strong if you put load on them lengthwise, but they're weaker if you load them sideways. (Kind of how duck tape is very strong if you pull it lengthwise, but you can easily rip it across.)

Buildings are constructed to mostly take loads from above, not sideways (except for wind loads); so when they're attacked from the side, they're vulnerable.
CAR INTO CHEPSTOW CLOSE CRAWLEY.jpg
 
The axial system of a structure like a high rise is transferring dead (the building materials) and live. ( the stuff on the floors) and the super imposed dead loads (equipment) to the foundations. Steel columns ... rolled sections or even built up sections are also used as beams... to support the live and super imposed dead loads to the axial system. The loads are additive so the columns strength must increase as you move down the building.. At the top they are pretty light sections... a thin as 1/4" thick webs and flanges... compared with 5" at the bottom.

A veneer brick application has no lateral strength.
 
Above is your original assertion, below is the evidence you rely on.

Even with the slower bomber, a part of the wing "made it" fully through the building.
Your assumption that the wings are the "weak point" and that they would have less power to penetrate the building than the fuselage is not supported by evidence.
Yes that was an incorrect assumption of mine that the wings are the weakest part of the building and would not be able to penetrate the building as well compared to the fuselage. I began with incorrect assumptions about both the strength of the plane wing and assumed that at a slower speed the plane would not fully penetrate the building. I shouldn't have done that and stated it so authoritatively like I was sure, when I was unsure of this to start with.
There is absolutely nothing in any of the sources you cited that supports the "understanding" that a wing came off as a result of a collision. You failed to undertake even minimal effort to ascertain that your sources actually support your claim, and surreptitiously placed that effort squarely on the reader. This approach to discussion demonstrates a lack of respect for the truth, and a lack of respect for the people you are engaging. Your apology doesn't even begin to cover that.
I am sorry for not taking the time to ascertain that my sources actually support my claim. I was in a hurry to provide a response and thought that those sources incidents where part of the wing was coming off the aircraft because I had thought I had seen the wing coming off as a result of a collision in these incidents when in all the cases, only the wingtip came off and the aircraft wing was intact, or the airplane wing did not come off at all and was not the first part of the aircraft to come loose. I did not intend to disrespect you or waste your time and I'm sorry that I did.
 
If Liberty Street was littered with small bits of aircraft wreckage and human remains after the Flight 175 crash, that would mean that some of the content in the rear and tail end of the aircraft didn't make it into the building, despite still having enough momentum to make it into the building. I don't understand why that would be the case. Perhaps the jetfuel explosions occurring after the plane fully went into the building blew out aircraft and body parts back out of the impact hole and onto Liberty Street?
That's right. However, the lighter parts of the wing tips and vertical stabilizer shattered on impact and did not enter the building.
 
That's right. However, the lighter parts of the wing tips and vertical stabilizer shattered on impact and did not enter the building.
I was confused about how some of the aircraft and body parts exited the impact hole and fell back onto Liberty Street and also about whether any part of the wing would penetrate the exterior steel facade of the tower if the airplane was flying much slower (similar to the lost in fog scenario).

However, after discussing it with others here, I think I've realized that the ensuing jet fuel explosion from the wings (after they had entered the building), blew the aircraft and body parts (which previously mainly had forward momentum into the building) in all directions, including back out of the tower's impact hole (explaining why some aircraft and body parts fell out of the impact hole and onto Liberty Street), and that even if the plane had been traveling slower, most of the wings would have still entered the building.

The Purdue WTC simulation of the first plane impact shows that the jet fuel tanks in the wings did not rupture until the plane had fully passed into the building (2:30).

I'm thinking that the demolition squib-like explosions from the floors right above the impact zone are the beginning stages of the jetfuel explosion before the fuel has fully ignited and produced a fireball, as the explosions seem to begin only after most of the airplane (including the wings) have entered the building.

This can be seen in the Naudet video (0:12, with squib-like explosions coming out of the far northern part of the west face, but showing that most of the plane (including the wings) had already entered the building)).

If this is the case, then even in a slower plane impact (such as what the design engineers had in mind when designing the WTC), the demolition squib-like explosions would still occur, as most of the airplane wings would be able to penetrate the facade and the fuel tanks would rupture once the wings were in the building, leading to a jetfuel explosion.
 
...
I'm thinking that the demolition squib-like explosions from the floors right above the impact zone are the beginning stages of the jetfuel explosion before the fuel has fully ignited and produced a fireball, as the explosions seem to begin only after most of the airplane (including the wings) have entered the building.

This can be seen in the Naudet video (0:12, with squib-like explosions coming out of the far northern part of the west face, but showing that most of the plane (including the wings) had already entered the building)).

If this is the case, then even in a slower plane impact (such as what the design engineers had in mind when designing the WTC), the demolition squib-like explosions would still occur, as most of the airplane wings would be able to penetrate the facade and the fuel tanks would rupture once the wings were in the building, leading to a jetfuel explosion.
Have you considered that the plane has a large volume that extremely rapidly displaces an almost equal amount of air in the offices? This creates a high air pressure, and that air has to go somewhere. Air pressure propagates at the speed of sound.
 
So then, the brown cloud at the top of the North Tower was merely dust that had accumulated in ventilation louvers on the 108th and 109th floors that supplied fresh air to the floors where the aircraft impacted. The pressure wave from the crash forced the dust in the louvers to be violently expelled resulting in visible dust clouds on the north and east sides of the building.

Have you considered that the plane has a large volume that extremely rapidly displaces an almost equal amount of air in the offices? This creates a high air pressure, and that air has to go somewhere. Air pressure propagates at the speed of sound.
Precisely. :)
 
Have you considered that the plane has a large volume that extremely rapidly displaces an almost equal amount of air in the offices? This creates a high air pressure, and that air has to go somewhere. Air pressure propagates at the speed of sound.
Yes I have, but I didn't think that alone would explain the squib-like explosions closer to or on the impacted floors, and thought that jetfuel explosions would be a bigger factor in producing the squibs. I also thought about how the plane would act as a piston of sorts in displacing the air in the tower, but I again wasn't sure whether this mechanism was actually valid so I didn't mention it previously.

Farther up in the tower (on the 108th and 109th floors), the explanation by @Marc Powell about how the "squibs" higher up in the tower were dust in the ventilation louvers that was shaken by the impact and pressure wave makes sense.
 
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