There's no need for a bomb check either. They have everything they need to build a bomb in the cockpit(or areas they have easy access to).

The axe is just one of the things they have there...

Screening pilots is simply idiotic. They have everything they could ever wish for in the plane. A simple knock/axe on the head of the co-pilot, and they can do whatever they want. If the pilot turns out to be a terrorist, no security checkpoint in the world will be able to stop it.

Unless, of course, they come up with a way to screen our brains....