The Case of the Missing Helicopter

[spooked911]

Check out after the 2nd hit in this video: http://www.youtube.com/watch?v=_-_EEiEUei8
at 0:47, a helicopter comes out from behind the North tower.

I have been unable to see this helicopter, which would have had a great view of the 2nd hit, in any other 2nd hit video.

For instance, look at this video of the second hit, which clearly shows the west side of the North tower, and no helicopter in that position for any time after the hit.

http://www.youtube.com/watch?v=DhBBdibvaLg

This is clear evidence of video compositing at some level. Particularly interesting is that the first video, which doesn't show a plane, shows the helicopter, indicating that the helicopter was deleted from videos with the plane.