I just have one question. With all the video cameras on the grounds of the Pentagon, why wasn't any video released of the plane hitting the building?
I heard that ALL the security system videos were confiscated & never released nor shown.
The plane was traveling at over 500 feet per second. A high quality security camera has a 1/10 of a second reaction time to send a frame of a picture. In that time the plane moved over 50 feet. All you see on the screen or on the video recording is a slight blur. The background still lingers for that same time so even the blur seems to be transparent and you can still see what is behind the object being recorded.
We live near Heathrow Airport, & our church is almost under the flight path. We see (& hear!) the planes as they approach, pass & pass on. A video doesn't just record the square-on view, but some would record the approach & passing so it would be very obvious in some videos what the plane was as it would be in view for several seconds even if they were flying at double the normal landing speed.
The still photo capture option on the video camera takes a still shot once every 1/2 second. In that time the plane moved forward 200 feet. A Boeing 757 is 155 feet long. You do the math. ......
Assuming the exposure time for a still shot is 1/50 seconds (you tell us the correct time) the plane will move 8 feet & would be clearly identifiable as a plane.
Remember the plane came in at ground level so would be recorded on a number of security systems.