As far back as September 2001 the order was issued to USAF to shoot down any airliner that didn't respond to instructions, they would have done it then and they would do it today.
So when the terrorists have clearly communicated they are in complete control & are going to crash on a Very Important Building where do you shoot the airliner down & where does it fall? Having been travelling at 300 - 400 odd miles an hour & hit with one or more high explosive AA missiles travelling at supersonic speeds does it just fall in one piece in a convenient empty field?
If it's that far away from the VIB how does the govt decide the threat is going to be carried out successfully anyway.
Utter nonsense.
Let's just replay 9-11 for a second - at what point & where would the jets that hit the buildings have been shot down?