I thought of this last night. Terrorists want coverage of their actions - how do you get coverage of planes blowing up in the middle of the ocean?
Those planes were going to be blown up on the ground, or over US territory.
The plane were going to be blown up over cities and operatives in the U.S. were assigned to tape the explosions and "rain" for propaganda videos.
I thought the same thing. Detonated over highly populated areas, all across the country, simultaneously or minutes apart - creating total hell and chaos.