Flight 77, the supposed plane that hit the Pentagon on 9/11 was a Boeing 757. It is the same plane that President Trump flies in.
A Boeing 757 uses one of 2 different engines: Either a Rolls-Royce RB211 or a Pratt & Whitney PW2000
Here is a diagram of a Rolls-Royce RB211. It says the opening of the turbine of a RB211 is 84.8 inches in diameter. (7 feet)
https://ars.els-cdn.com/content/image/3-s2.0-B0122274105003562-gr7.jpg
Here is a photo of President Trumps plane (757), look at the size of the opening of the plane turbine and the person standing next to the plane. Look at the center hub of the turbine, compare its size to the person standing next to the plane.
Here is a photo from the Pentagon on 9/11. Look at the round object behind the person on the left. That is the center hub of a turbine from the object that hit the Pentagon. Notice anything wrong?
I'm sorry, but I did research for a living. "Well researched" does not come up with the wrong answer. High effort means nothing if it is mistaken. In this case, the anon could have avoided the errors if he had simply become familiar with the construction of turbofan engines and what the components look like. There is no way that a worthy researcher would claim (in effect) that an inlet fan and a turbine disk were the same thing. That was the whole premise on which he hung his conclusion. We can't let sloppy research fuel empty conspiracy theories. It is a waste of time and a distraction from the truth.