How would you know a 747 is headed to the White House? This isn't a guy with a rifle pointing it at a target. It's a huge aircraft flying extremely fast that could theoretically hit anything within a multi-mile radius in far less time than a fighter pilot can ask permission to fire.

It's like the Die Hard 2 plot hole. The whole movie was predicated that planes were headed to Dulles and couldn't land, and if they didn't get down they would run out of fuel and crash. If Dulles were an island thousands of miles from any other land mass, then that's an interesting plot. Since there are dozens of airports within a half hour's flight from Dulles where you can land a plane, the plot is just stupid.

It's similar to sending up fighters to make sure a plane lands where it should. We don't have too many airports that are 20 miles in the middle of nowhere with zero development around it.

The fact that they don't divert a suspected plane to some rural area airport or more likely, a military airfield, since some of those are the only ones that fit the rural yet large enough parameters, then it is just theater. TSA makes you throw your water away because it may be an explosive. Yet, they throw it in the trash can right by the scanners. They know it's just water, but rules are rules. If anyone thought there was a legitimate chance it was explosives, then every liquid would be treated by a hazmat team. There also wouldn't be the 100ml times x bottles for a max of 1 liter exceptions. That's mathematically asinine, but was implemented instead of simply backtracking completely and admitting that the liquid ban was stupid and unnecessary.

So, if the FAA/NORAD were seriously worried that a hijacking was underway, they would divert every plane to some rural area. They don't - they escort the plane into whatever big commercial airport it was headed to. Which is surrounded by plenty of targets that could be hit easily by the pilots.