Originally Posted by
catocony
Except that there are three huge commercial airports within 30 miles of downtown DC. One of which is immediately across the Potomac. Taking the America bashing out of your argument, if the Air Force were to shoot down a commercial aircraft, it would most certainly be over a populated area. Simply having a plane off-course and non-responsive is not a justification for definitely killing everyone on the plane and a lot of people on the ground - plus property damage. Short of a hijacker on the radio scream "death to America", there would not be a way to be 100% sure of a 9/11-style attack underway.
It's somewhere between very difficult and impossible to get a fighter jet off the ground fast enough and into the air into a position to "escort" and then shoot down a plane that has been unknowingly (on the ground anyway) hijacked but only diverted from the Potomac River flight course within a handful of minutes of scheduled landing at DCA. The area is rather densely populated. If 9/11-style terrorists were doing a replay of 9/11 and doing so around the DC area, there is no shortage of populated areas along that flight course. Amongst the increasingly densely populated area are various office buildings and residential buildings popular with rather highly-educated government and government contractor employees and dorm buildings for universities. The "escort" is not going to generally work to avoid populated area shoot-downs when terrorists target places in large metropolitan areas like DC and the diversion from flight course for an "unknown" hijacking by 9/11-style terrorists happens within a handful of minutes from scheduled landing time.