Question for Ryan Mackey

[R.Mackey]

The center of the main deck is horizontal and in order to give the headroom in the cabin of the 16.5 foot diameter fuselage is probably just below the center of the fuselage. If the aircraft rolls down to the left then the main deck will be more to the right of the core columns.

I guess you didn't understand me the first time. The roll axis of the plane passes through the main deck. Roll does not lead to displacement side to side. Even if it did, we're talking about a tiny shift, well within the ~2 foot margin of error in NIST's point of impact.

This is not significant at all.

I am wondering if R MacKey can explain one thing - what about secondary debris. The
impact of the aircraft as it ploughed through the building would have picked up anything
in its path - structural materials (exterior columns, pieces of floor truss), interior
partitions, furnishings et al. What would have been the result of these secondary
missiles on the building structure?

NIST attempts to model the interior, using "typical" workstations and partitions. They get largely swept up and destroyed, and this tends to spread the momentum of impact a bit. More importantly, this mixing of aircraft and furnishings leads to removal of fireproofing, even if the secondary objects tend not to have much structural impact.

Even more importantly, the final disposition of furnishings governs where and how much fire there is afterward. This is actually a significant effect.

The floor slab is strong. But it's not going to develop the strength that you're talking about. What would be the compressive strength of a 4" plate that's 208 feet square? It has a b/t ratio of 624. Something tells me that local failures will occur long before any real compression is developed.

Oh whoops, there we go again, using real engineering.

Yup. However, the floor slabs are also massive, and therefore siphon off a good chunk of the momentum, even if they're expected to fail at impact.

NIST's own results show this. Compare the floor damage predicted in the baseline vs. less severe and more severe impacts in NCSTAR1-2B, and you'll see what I'm talking about. (Newtons Bit I assume already knows this; I mean this as a general comment.)

 

[Tony Szamboti]

The floor slab is strong. But it's not going to develop the strength that you're talking about. What would be the compressive strength of a 4" plate that's 208 feet square? It has a b/t ratio of 624. Something tells me that local failures will occur long before any real compression is developed.

Oh whoops, there we go again, using real engineering.

Pretty gracious with yourself aren't you. Those floors had two sets of 1/4" rebar grid in them and there were a number of trusses involved. Of course there would have been local buckling failures, but it would probably not have buckled the entire length of the floor. The real issue is what damage going through the length of the floor does to the plane. The plane would have been hitting the floor edge on, not just diving down through the thickness. It would have had to plow through the length of the concrete with two sets of light rebar in it and trusses with buried knuckles in the concrete. That would appear to have done much more reduction to the momentum than diving through the floor.

That something that tells you that local failures would have been involved needs to be fleshed out a little better to be real engineering.

 

[Tony Szamboti]

I guess you didn't understand me the first time. The roll axis of the plane passes through the main deck. Roll does not lead to displacement side to side. Even if it did, we're talking about a tiny shift, well within the ~2 foot margin of error in NIST's point of impact.

This is not significant at all.

It is 2.2 feet, which when talking about a 16.5 foot diameter projectile, with an 8.25 foot radius, it is 26% of the radius. That would seem significant.

How many feet of difference is it between the 6 degrees of pitch and 10 degrees that you feel would make a difference in whether or not there would be significantly less damage to the plane? I am trying to understand the basis of that argument as the fuselage had a 16.5 foot diameter and material of the floors was less than 12 feet apart. Thus the fuselage cannot miss the floors no matter what the pitch angle, and the shearing of the long top and/or bottom of the fuselage would have had a significant impact on momentum. In fact, one would have to crunch the numbers but it would appear to be much worse than diving down through a floor, and if that is true then at some point more pitch angle would seem to help the less damage argument.

 

[LastChild]

You need to read NIST more carefully. "Nominally 8 degrees" is what NIST shows in Table 7-3 of NCSTAR1-2B, or more correctly 8 +/- 4 degrees, but this is only the result after video analysis. NIST's refined estimate, which also includes analysis of the exterior damage, revises that figure to 6 +/- 2 degrees, as shown in Table 7-4 on Page 170 of NCSTAR1-2B. You should quote the refined figures, not the video-only figures.

See realcd? You forgot the refined estimates. You can't forget all the refining when it comes to the NIST report if you want to buy into it.

 

[eeyore1954]

Quote from Bell about the nose of the plane after it "flew out the other side of the building

Then it flew on to Cleveland

Very funny , excellent line.

 

[Tony Szamboti]

RealCD, how does a plane going through a building rigged with explosives not affect the demolition charges?

You could have answered this question for yourself by learning what floors had aircraft impact damage in each tower and what floors the collapses initiated on.

The actual collapse floors, 82nd in the South Tower and 98th in the North Tower, had very little impact damage.

 

[Tony Szamboti]

The floor slab is strong. But it's not going to develop the strength that you're talking about. What would be the compressive strength of a 4" plate that's 208 feet square? It has a b/t ratio of 624. Something tells me that local failures will occur long before any real compression is developed.

Oh whoops, there we go again, using real engineering.

How does the b/t of an entire one acre floor area of the towers have any relevance? The distance between columns of the floor is 35 feet for the side of the South Tower which was hit. Why would you use a b/t for the entire floor of the tower? In reality, the trusses would also make a difference in stiffness of the 4.35 inch thick concrete floor with two sets of 1/4" diameter rebar grid in them. The steel floor pans, while thin gauge were corrugated which would have increased the stiffness of the floor assembly in the longitudinal axis of concern.

Your attempted dig about real engineering is very poor form, considering your use of an entire floor area, which has no relevance.

 

[Newtons Bit]

How does the b/t of an entire one acre floor area of the towers have any relevance? The distance between columns of the floor is 35 feet for the side of the South Tower which was hit. Why would you use a b/t for the entire floor of the tower? In reality, the trusses would also make a difference in stiffness of the 4.35 inch thick concrete floor with two sets of 1/4" diameter rebar grid in them. The steel floor pans, while thin gauge were corrugated which would have increased the stiffness of the floor assembly in the longitudinal axis of concern.

Your attempted dig about real engineering is very poor form, considering your use of an entire floor area, which has no relevance.

Sorry there buddy, the core columns don't resist lateral forces, they do not brace the slab, they're just along for the ride. You could argue that they would roll-guide the center, but that's a different matter.

I also recommend learning how extremely thin (that's the b/t ratio) plates act. They will NOT develop the bending capacity based on a moment inertia like you implied they would in post #28. You were actually correct when you implied (though you couldn't figure out the word for it) that it would be a shearing failure at the point of impact in post #42. We in the structural community like to call that a "local failure" since it's not causing the entire element to fail.

Truther engineering at it's best!

 

[Newtons Bit]

NIST's own results show this. Compare the floor damage predicted in the baseline vs. less severe and more severe impacts in NCSTAR1-2B, and you'll see what I'm talking about. (Newtons Bit I assume already knows this; I mean this as a general comment.)

I'm pretty much thinking that the plane is going to get severed at several pieces by the floor slab. Kind of like the plane passing through a really big cheese-grater.


edit: I wonder what kind of damage a block of cheese going at 500mphish would do to a steel cheese grater? I'm hoping someone will do an experiment on this. And tape it.

 

[Swing Dangler]

Impact, fire, collapse. Simple stuff you can't even understand. What a total waste of your engineering training. The buildings could survive impacts at slow speed. Not high speed. Slow speed ins below 200 knots. I was educated by some of the top control engineering professors in the world.

So 600 mph's is slow to you? Lordy, I hope I never have to see your designs in reality. And what does that say about the "engineers" who educated you?
Lets examine your statement based upon the Engineers at NIST and their statements about the speed of the plane the towers were designed to withstand. Stop promoting lies, Beachnut. I just ripped your comment apart based upon basic research and NIST!

 

[Bell]

So 600 mph's is slow to you? Lordy, I hope I never have to see your designs in reality. And what does that say about the "engineers" who educated you?
Lets examine your statement based upon the Engineers at NIST and their statements about the speed of the plane the towers were designed to withstand. Stop promoting lies, Beachnut. I just ripped your comment apart based upon basic research and NIST!

Swing, I showed you NIST statement about this claim before. Did you:

A) not read that?
B) deliberatly choose to ignore NIST's statement?

ETA: http://www.internationalskeptics.com/forums/showthread.php?p=3120302#post3120302

 

[Gravy]

That something that tells you that local failures would have been involved needs to be fleshed out a little better to be real engineering.

I wonder where a person could read a detailed study about that.

In fact, one would have to crunch the numbers but it would appear to be much worse than diving down through a floor, and if that is true then at some point more pitch angle would seem to help the less damage argument.

It's too bad a detailed study about this isn't available for all to read for free.

You could have answered this question for yourself by learning what floors had aircraft impact damage in each tower and what floors the collapses initiated on.

The actual collapse floors, 82nd in the South Tower and 98th in the North Tower, had very little impact damage.

I vaguely recall a detailed study that shows how wrong this is, and that describes something – I think it might have been...fire – that followed. Wish I could remember where I saw that. Maybe someone who hasn't ◊◊◊◊ upon their engineering degree will know.

 

[Gravy]

NVM

 

[jhunter1163]

I'm pretty much thinking that the plane is going to get severed at several pieces by the floor slab. Kind of like the plane passing through a really big cheese-grater.


edit: I wonder what kind of damage a block of cheese going at 500mphish would do to a steel cheese grater? I'm hoping someone will do an experiment on this. And tape it.

Sounds like a job for the Mythbusters!

 

[Swing Dangler]

Swing, I showed you NIST statement about this claim before. Did you:

A) not read that?
B) deliberatly choose to ignore NIST's statement?

ETA: http://www.internationalskeptics.com/forums/showthread.php?p=3120302#post3120302

Just read it. I don't accept that excuse of course. As we all know the buildings withstood the impacts. Apparently there are two cases that support the white paper's statement. Or do you disagree with that?

Or are you suggesting that Engineers make arbitrary statements without evidence?

I find it rather interesting that NIST found no documents supporting the original February 1964 white paper analysis nor Les Robertson's study later in 1964.

 

[WildCat]

In reality, the trusses would also make a difference in stiffness of the 4.35 inch thick concrete floor with two sets of 1/4" diameter rebar grid in them.

Nope, there was no rebar in the lightweight concrete floor. It was simply concrete over the corrugated steel pan, supported by trusses.

It was a floor, not a highway.

 

[Mr.Herbert]

Swing Dagler claims Mackey is a liar?

Thank you sir. It isn't too difficult debating those guys as long as you know your facts and can point out their errors. I've taken Rmackey to task on a couple of occasions and exposed his lies and distortions. I just hope my taxes weren't paying his bills while he was in a discussion with me.
I'm not sure, however, why a MOD here would remove two publicly available email addresses other than to make contact with them more difficult.

There are several biased mods at JREF and I have personal communication from one to support Chillzero's position and hypocrisy in moderating the forums.

http://www.abovetopsecret.com/forum/thread313448/pg6#pid3696352

 

[Mr. Skinny]

(snip)Software for cockpit research projects, and voice recognition at AFWAL. (snip)
.

Hey, beachnut, did you work in the Bldg 145/146 complex where the LAMARS (Large Amplitude Multi-Mode Aerospace Research Simulator) was located?

 

[1337m4n]

See realcd? You forgot the refined estimates. You can't forget all the refining when it comes to the NIST report if you want to buy into it.

Would you rather every scientific report in existence appear only in the form of the initial rough draft? Keep in mind that your "Loose Change" has probably gone through more revisions (most of which involved editing out debunked arguments) than any NIST report.

 

[Crungy]

Swing Dagler claims Mackey is a liar?

http://www.abovetopsecret.com/forum/thread313448/pg6#pid3696352

Also from that forum.

Swing is a stand up guy, I've watched him kickin debunker butt over at JREF.

I have never read any evidence supporting the above claim. If anyone has could they please direct me to said post.