One of the obvious questions which I have not heard a good answer to: How did the terrorists get into the cockpit? Isn't it supposed to be locked from the moment the aircraft pulls away from the gate?

It seems to me that the simple precaution of locking the cockpit will be effective.

I agree wholeheartedly with two comments:
- there is no way to search everybody and prevent any possible weapon from getting on board the aircraft. it is unrealistic and there will constantly be new and better weapons. Even profiling will not prevent well prepared terrorists from getting onto the aircraft with a weapon.

- we are to blame for the situation with security. We push for lower fares. We push for convenience. And we complain when we don't get it. We drive the process.