The no planer is a no brainer. Ask the survivors in the tower what they saw.
My name is Jeff Benjamin and I was visiting a client, Axcelera Specialty Risk, on the 83rd floor of the North Tower when we observed an approaching aircraft (American Airlines Flt.11)from a distance of aprox. 3-4 miles. At the time we initially spotted the plane, it appeared to be level with us. We could distinctly identify the American airlines insignia and my client commented that perhaps the plane had taken off from Kennedy and was experiencing mechanical problems. As the plane approached us it seemed to climb. I stood up from the conference table and walked over to the window assuming as everyone did that there was no imminent danger. As the plane came closer we could see that it was traveling at a high rate of speed and the sound of the engines intensified. Immediately before impact we could see images in the cockpit and the plane banked sharply. A split second later we heard an echoing shot, fell to the floor and observed a fireball followed by debris which struck the side of the building. At the same time you could feel the building sway every so slightly for a brief moment. We immediately retreated towards the main part of the office where we noticed a huge fireball shooting out of the elevator shaft which quickly disappeared. Source
From a window on the 61st floor in the north tower, Ezra Aviles had seen everything. He knew it was no bomb. His window faced north, and he saw the plane tearing through the skies, heading straight for the tower. It had crashed into the building over his head-how far, he was not sure. Jim Dwyer and Kevin Flynn "102 minutes, The Untold Story of the Fight to Survive Inside the Twin Towers." Henry Holt & Co. New York.; 2005.
I heard the loud roar of airplane engines outside. I turned in my chair so that I could see out the window. About three or four plane lengths away, I saw a huge jetliner coming at the building. I said, "That guy is low!" I spoke loud enough that my colleague sitting in the cubicle next to mine heard me. I saw the nose of the plane and then the smooth underbelly and one of the wings. It was just above me, a little bit to the right, and slightly bent so the wing over me was higher than the other wing. I couldn't see any windows or recognise any markings but I noticed the landing gear was up. It had just registered that this was no small plane when it entered our building two floors above me. –George SleighSource
"I saw the plane come in. My office faces north. I just finished my coffee and I heard my friend say, 'Oh no, oh no.' This plane was coming right at us, then it went up and hit the upper floors. –Nicholas Scinicariello, 86th floor Source
Scimitars were not available - beware January 19, 2038 is upon us.