In case you missed it, the point to all this is that trying to predict what terrorists will do is moronic and having a security régime based around it is suicidal. The only way to keep airlines hijack-proof is what has already happened: Make people completely unwilling to sit still and listen to hijackers. People finally realize now that once their plane is hijacked they’re as good as dead, so they might as well work to prevent any further deaths even if that action hastens their own. What we have yet to realize is that basic probability works.