Tarpley isn't an engineer, and doesn't focus all that much on that aspect. He lets others do that.
He talks more about the many inter-related systems that all had drills, breakdowns, 45 minute blocks of being offline, and in the case of one, completely had the day off on 911. Then the complete Griffin report on the 911 report omissions...
Eh, don't worry about it. Grown up shit, a little more than a blurbed pop mech article arguing with some loose change kids splicing together news footage.
Whatever dude. You shit your pants on 911, and so you'll believe every CT except that one youre emotionally involved with. You haven't done your research if you haven't read Tarpley. Hey, at least your eyes are open to some of the truth, so props for that.