Just curious, how is the Cooper-Harper scale used during flight test? Is it based solely on the flight test pilot's opinion? I know flight test pilots have to have a gajillion flight hours in many types of aircraft. This obviously helps the pilot to "grade" a plane.
How does a pilot know when to say "I'd like to have this XXXX part of the control law tweaked" as opposed to saying everything's hunky-dorey? How do they learn to evaluate the plane?