Keep looking at that short video and play it back as often as needed, and you will see the while smoke trailing the aircraft and the verfical stabilizer as well just before impact.
The landing gear wheel of American 77 at the Pentagon.
B-757 landing gear
This is how American 77 approached the Pentagon just before impact. You can see the vertical stabilizer and while smoke trailing in the background.
Now, take a look at this aerial view and note the white trail leading toward the Pentagon.
Edited by skyeagle409, 28 December 2011 - 09:14 PM.