"
Yes, the analysis took the B-25 Empire State Building crash as a model, and assumed a 707 lost in bad visibility, at mandated 200 kt max airspeed for operations below 10,000 ft, as the NYT reference notes (page 13). It appears from the article, now that I re-read it, that somebody at Yamasaki or Emery Roth's offices heard a garbled version. The article also points out on the following page that nobody considered the fire, as Zdawg notes: there's no discussion of why, though I suspect my theory is close to the mark. Studies of that kind are expensive, and if Robertson wanted to do the structural calcs on his own dime, that didn't mean that the owner or architect would ante up for a full study of an airplane-induced fire.  (talk) "