That piece of the plane was all that was left that far in front of the building... and nothing else in between. Give me a break.
I looked at all the pictures at that site: they ALL are completely consistent with the standard theory (big passenger plane hit Pentagon). All the surrounding text is an obvious stretch at creating FUD; even the top-down photo with impact directions is plainly mis-drawn.
This is a really pathetic attempt to claim a conspiracy. There's lots of photographic proof, and it all makes sense...including the parking lot video.
There are plenty of real conspiracies to worry about; why waste your time inventing one where it obviously does not exist?