airliner could be leased by a dummy corp. as a executive jet......a 737 or 727 packed with explosives would be more than enough.....there are plenty of 727's used as executive jets
OK, good points. However, that would require a LOT of assets being pumped through the dummy corporation over a long period of time--owning and operating an airplane ain't cheap, and people start wondering what the heck's going on when one AIN'T flying for a while, unless they park it out at Mojave Airport--and the Feds have been known to keep an eye on Mojave just because so many questionable activities, like parts theft, take place there.
The best terrorist plots have the advantages of the best military plans: speed, surprise, simplicity. 9/11 used all three.