NTSB report based on the 757's flight data recorder found in the pentagon:
"At 9:34 AM, the aircraft was positioned about 3.5 miles west-southwest of the Pentagon, and started a right 330-degree descending turn to the right. At the end of the turn, the aircraft was at about 2000 feet altitude and 4 miles southwest of the Pentagon. Over the next 30 seconds, power was increased t onear maximum and the nose was pitched down in response to control column
movements. The airplane accelerated to approximately 460 knots (530 miles per hour) at impact with the Pentagon. The time of impact was 9:37:45 AM."
He flew to the pentagon then did a descending standard rate turn (standard rate meaning it's the rate of turn used for instrument flight procedures every day by ever pilot on earth) until he was roughly lined up four miles away at 2000 feet. Not low level. Not crazy turns. Not crazy speed. Then he nosed it over and throttled up over 30 seconds to fly somewhat imprecisely into an enormous building.
The pilots saying it was a difficult maneuver either had the maneuvering misrepresented to them or they're lying or they're smooth brainers like the rest of the truther crowd.
Edit: Looks like it was actually a significantly more benign turn than standard rate, which is 3 degrees per second, and this turn was apparently less than two degrees per second.
https://www.ntsb.gov/about/Documents/Flight_Path_Study_AA77.pdf