He was amazed by the reported feats of the hijackers on 9/11 doing things with supposedly commercial Boeing 767 planes that could not normally perform at the parameters given in the official story, including the published printout of the FDR from AA 77 that was reported to hit the Pentagon.
Just now, we won't get into the fact that the FDR shows on ascent to 18,000 feet and above, there is and adjustment made for the altimeter that is based off pressure. It was adjusted to 29.92 for flying above 18k. The plane turned around in Kentucky and flew back to the Pentagon area. When it descended below 18k and you are supposed to adjust the pressure for your altimeter to that of your destination area (such as Dulles Airport,) that was not done. So, the recording stops at the supposed crash, which shows the plane about 150 off the ground. That is a problem because not only did the plane supposedly fit into a 16' X 19' hole on the ground floor, the Pentagon is only 80' high.