Yes but they trained for that and once the word was out they didn't even scramble the F-15's until all planes had hit their targets with the exception of flight 93. But on top of this, the Bush Administration and particularly the CIA and NSA should have been on top of this stuff.
How close were the planes to the towers when it happened?
Also, if Bush shot down an airplane full of people with an F15, everyone would give him stuff for that too lol.