Greening: Nist model "highly inaccurate"

Frank Greening is a scientist interested in why the WTC collapsed and has written several papers of the subject, some of them in response to Steven Jones' arguments. For example, you can find his Energy Transfer in the WTC Collapse here: http://www.911myths.com/WTCREPORT.pdf
He concludes that the WTC was destroyed by the impact damage and fire.

He has also written an assessment of the NIST Report, which you can find here: http://www.911myths.com/NISTREPORT.pdf
Although he is a supporter of the impact and fire theory, he finds some shortcomings in NIST's methodology. After discussing NIST's take on the angles at which the towers were tilting prior to collapse initiation and the vertical displacement this caused, he concludes (p. 13):

"Clearly, if NIST's computer model is essentially correct, the Twin Towers collapsed (or fell over!) at ridiculously small downward displacements and tilt angles, and were inherently unstable as soon as they were struck by aircraft. This raises serious questions about the design and construction of the Twin Towers. However, a more reasonable assessment would be that NIST's computer model is highly inaccurate, and therefore of no value in explaining the demise of the Twin Towers."

Obviously, Greening is only one man, but it will be interesting to see how the debate goes.

btw, thanks to the nice people at 911myths for debunking the NIST report for us.

but that was a key aim of the demos -- to get those huge towers to fall without knocking over any neighbors. Quite a feat when you think about it.

So how could he possibly believe that plane and fires caused the collapses?

p.s. I'll open the .pdf files later.

You ask "So how could he possibly believe that plane and fires caused the collapses?"

He (more than) doubled the actual weight of the towers and he (almost) doubled the amount of damage caused by the aircraft (compared to NIST's base case).

He is being deliberately deceptive?

The WTC is commonly supposed to weigh twice a much as it really did. I'm not quite sure why, but my best guess is that people just take the headline figure for the entire weight of the original Twin Towers complex (i.e. including all the concrete in the basement) and divide it by two. A more careful look reveals that each tower should have weighed about 250,000, which is the number NIST goes with.

He just pulls the extent of impact damage out of his ear, there's no working for it I can see.

As far as I can tell he also gets the cross-sectional area of the 283 columns wrong as well, but this time he gets it wrong in a way that makes the towers stronger. He then gets round this by redistributing the entire tower's weight in such a way that it's only placed on a few columns.

Okay I looked at the .pdf and it appears that what he means by "ridiculously small downward displacements and tilt angles" is that the NIST underestimated how far the top of WTC 2 sagged and tilted before the grand finale.

And as you say, he stands by the claim that the falling tops triggered a "global collapse," but he thinks his bigger "displacements" make it more credible.

Well, they don't. The problem remains that no matter HOW much damage the plane crashes and fires did to the floors they occurred on, they wouldn't have weakened the structures below.

So even if 10 jumbo jets had hit each tower, the worst that would have happened is that the upper sections would have toppled onto the very profitable WFC or another building ringing the site. But the lower 80-90 floors would have stood.

This seems pretty obvious to anyone who cares to study the matter, as Greening appears to have, which leads me to the conclusion that his report is just another attempt to prop up the OCT with bogus chicanery.