“What are you talking about?”
Bring up a picture of the pentagon on 9-11 and try to find the airliner. You won’t find it. Of all the tinfoil theories about 9-11, that one is the most interesting. Some Frenchman was the first to point that out and theories snowballed from there.
Yes, because it was thin metal hitting a thick cement wall at 500 miles an hour. It disintegrated.
Here's a video of a plane hitting a cement wall, for reference.
http://www.youtube.com/watch?v=Zl0MhOdkREQ
Where'd the plane go? It's gone! That means it never existed at all!
Actually it isnt a mystery. A camera shooting at 1 frame per second with a field of view of about 30 yards versus a jet flying at 500mph- the odds are against a passive camera catching it.
Its interesting until you hear the first responders talk about finding still-uniformed bits of the aircrew scattered about the pieces of aluminum, in airline livery, and airline seats.
This is an old bad one. There is a pic at the pentagon of a shot looking at the damage with a piece of the plane in-front. I even seen were conspiracy people had to edit out the piece in order to make their statement.