The Presidential Daily Briefing for Aug 6, 2001 is online, or at least a declassified version of it. It’s pretty vague: what would be more useful would be to know what came of the 70 investigations mentioned therein.
See also this piece that looks at attempted terrorism incidents before and after 9/11 and what it suggests about the security precautions in use before and after.
And the previous entry at the same site references the Transportation Security Administration’s “obsession with pointy metallic stuff”. Makes you wonder if there are any real security strategists in the room when they think these things up. Isn’t one of the basic tenets of thwarting this kind of behavior to think like the other side? This gem came from the comments:
So all you need to ignite the body of the plane is a magnesium block firestarter (standard GI issue–available at any camping or surplus store). Ignite a large pile of shaved magnesium from the firestarted on top of exposed aluminum.
Imagine a coordinated offensive of these simple one man attacks . . . . and how little has changed to prevent it.