Why the 9/11 Hijackers had the time to do what they did

I have seen lots of post here on why the response was not faster on 9/11.

The biggest thing is something I have never seen brought up. That is the fact that no one had ever flown a plane into a major building before. This was a major contributor to the actions of 9/11. Before this time hijackers had always land their planes and asked for something, or told the pilots to fly somewhere. The standard response was to allow them to fly to the destination and then handle the issue on the ground.

So the hijackings themselves should not have put a big “Terrorist” flag up. Yes 3+ hijackings at once would alert people to a problem, but not what was going to happen.

Even the first airplane to hit the towers would not mean it was a terrorist attack. It could have been that the hijacker was a bad pilot, or had no idea what he was doing and hit the tower by accident. This in fact would have cause more confusion. Now the people in charge would have to ask this very question. Was it an accident or on purpose?

It was not until the second plane hit could people defiantly conclude it was an attack.