aha, this is awesome! and indeed the solution he suggests (locking the cockpit door) is the only one of the various security measures put in place to prevent a recurrence that is generally agreed to have been effective rather than just security theater

i want to give pg a lot of credit for clear thinking here, but of course if he'd suggested locking cockpit doors in august 02001 instead of september, that would have been significantly more impressive

your original summary of https://paulgraham.com/hijack.html was not correct