"Dan" wrote in message
news:zU7Sf.62063$Ug4.53088@dukeread12...


I know WTC was designed to withstand a fully fueled and loaded 707
strike, but multiples? I dunno, I doubt it. It's irrelevant anyway since a
single 767 strike is different than multiple strikes by 707 or any other
aircraft. The fact remains the buildings were not designed to withstand a
767 strike simply because 767 didn't exist at the time the requirement was
made.


The consulting engineer on the WTC has stated that while
the building was designed to withstand an aircraft strike the
actual event was much more energetic than expected.

The scenario was impact by a 707 on a landing approach
to a New York airport with a low fuel load at a speed of
around 200 knots. What actually happened was a impact by
larger aircraft at more than double that speed with an almost
full fuel load.

As KE rises as a square of velocity this means the impact was
between 4 and 8 times the designed load

The building still withstood the blow but what it couldnt
stand was the subsequent fire which the original scenario
did NOT include.

Keith