I mean, what is the simplest way to prevent another 9/11? Steel cockpit doors and a communications shutoff between cockpit and everything outside.
Another 9/11 scenario is going to be near impossible to pull off. Pre-9/11 hijackings often left the passengers with some hope of living through the situation so they would be docile and controllable. Post-9/11 passengers will not be docile and the hijackers will have to effectively control the entire plane with force.
There is still run of the mill blow up the airplane style terrorism to watch out for, but that was around before 9/11 and will be around for long time after.
Another 9/11 scenario is going to be near impossible to pull off. Pre-9/11 hijackings often left the passengers with some hope of living through the situation so they would be docile and controllable. Post-9/11 passengers will not be docile and the hijackers will have to effectively control the entire plane with force.
There is still run of the mill blow up the airplane style terrorism to watch out for, but that was around before 9/11 and will be around for long time after.