Exactly. And what the heck did the hijackers want crop-dusters for? Joy rides along the Florida coast? Certainly, they didn't think they could knock the WTC with crop-dusters.
Where've you been? Down here in Florida one of our pasttimes is renting crop dusters and flying up and down the coast sprinkling deadly bio-agents over unsuspecting populations.
It's done all the time, I don't see why this should raise the eyebrows of our law enforcement bureaucracies.
Yup. Generally you wouldn't go looking for 'delivery' methods until/unless you have something to 'deliver.'