Most airplane attackers are, or at least since airplanes no longer take off with checked luggage from someone who hasn't boarded.

Non-suicidal hijackings have pretty much been eliminated by cockpit doors as well as 911 changing people's reactions.

> Most would-be attackers are not suicidal

That's definitely not an assumption in the threat model.

I could have said that better. I meant to say, the fact that you have to be suicidal to do the attack definitely reduces the pool of attackers.