Here's an article on the subject.
Radar Detected Airplane before White House Crash
I'm telling you, strait up, in the pre 9/11 world it would be political suicide for a president to order the military to shoot a civilian plain out of the sky. People would have been up in arms over it. Even in a post 9/11 world it would be a very risky manuvore for a president to order military fighters to shoot down a passenger plane. The investigation would have to PROVE without any doubt that he was in mortal danger for their not to be an outcry over it.
And that's the thing, people are trying to apply post 9/11 thinking to a pre 9/11 situation. That's all im saying. Why didn't Bust do this or that? Because on the morning of 9/11 such thoughts either had never been thought before or the political landscape would not allow such an action to take place without dire consequences.
Hindsight may be 20/20 but that doesn't mean you can just pick and choose when and where your going to apply it.