Originally Posted by
jagema
Underwing-mounted engines, being under the center of gravity, create a pitch-up moment when adding thrust. Pitch-down when reducing thrust. Easy to picture: letter T. Push the lower end of the vertical line, pushing force being the thrust vector forward. The junction of the T (where vertical meets horizontal axis) being the CG - The whole thing swings clockwise (nose up).
Need for MCAS is not related the thrust pitch coupling. Read previous thread entries to understand and catch up with the discussion.