Seymour,
I've pointed this out too to troofers.
A better comparison would be breaking out the windows vs poking holes in the screen.
If one wanted to do a proper comparison of what effects plane strikes would have, you would compare it to shooting holes in the screen door's frame.
My purpose in taking on Mr DiMartini's comments are a little more extreme. (He is a bona fide hero, for his selfless actions on that day.) But his understanding of structures was terrible.
There is a very common story running around that the towers were "designed to withstand the collision of a 707".
I am confident - for a number of reasons - that this is simply urban myth, that became legend within the towers. One that Mr. DiMartini heard & repeated.
The reason that it cannot be true is that we could not REALLY even accomplish that design today, with all the high powered computers & FEA programs available. Les Robertson admits to that fact here:
"We should not and cannot design buildings and structures to resist the impact of these aircraft. Instead, we must concentrate our efforts on keeping aircraft away from our tall buildings, sports stadiums, symbolic buildings, atomic plants, and other potential targets"
"Reflections on the World Trade Center"
http://www.nae.edu/cms/Publications/TheBridge/Archives/7344/7480.aspx
And this certainly could not have been done before the era of generally available software & hardware in 1964.
The book "Cities in the Sky" has a very interesting section on just this topic. And it appears to me that John Skilling did a very quick calculation to show that
1. the total "toppling" load that would be imparted on the towers by an impact would be less than the max design wind load. IIRC, it turns out to be slightly greater than the wind load, but still acceptably in the ballpark, according to Skilling. (And he turned out to be right about that.)
and
2. that the building would still stand if he surgically removed the external columns equal to the wing span of that jet.
And then produced a paper that undercut the attempts of Lawrence Wien (sp.??) who was trying to stop the WTC project.
I know that Roberton also did a later study that NIST referred to, but could not produce.
Anyway, it is that myth that I've tried to fight in discussions with other twoofers in the past. As you might expect, their response is, shall we say, frigid.
LoL.
tk