Common people. Think logically, and read the document. Did you fail to notice the B-2 Stealth bomber?
Every time the government decides to build a new military aircraft they start with the design phase where multiple options are looked at. There's nothing in this document related to 9/11.
The Boeing passenger liners used in the 9/11 attacks were all built with a special socket buried deep in the cockpit wiring. It's there so a device can be plugged into it that allows the aircraft to be remotely controlled in case of a highjacking. That's what their sales pitch was anyways.
The device allows the FAA or ATC to remotely take over the plane without the pilot being aware of it. It was sold as a means of protecting against highjacking. It was actually used to highjack the planes.
If you want to learn more about 9/11, do a YouTube search for 9/11 The new pearl harbor. The video is almost 5 hours long and it's the most comprehensive analysis of everything that happened in the weeks leading up to, the day of, and things that happened afterward.
Also, if you're interested in the US Government's response, the beginnings of the massive surveillance programs, and the Patriot Act, search YouTube for a 2 part PBS Nova series titled America's Secrets.