Gz in the fdr trace will be measured wherever the accelerometer is located. My guess is that it's located in the avionics bay. An abrupt pitch rate will produce opposing Gz rates at the ends of the aircraft.
Once the pitch rate goes to zero, unrestrained objects will tend to continue in the direction they have been accelerated, much like a catapult if in the rear during a pitch down. In front, unrestrained objects in negative Gz will head to the ceiling and drop back down when Gz rate returns to zero, as was demonstrated by an ashtray bouncing off the ceiling when I advised my instructor we were climbing into the path of another airplane on a converging course. He had been questioning my reducing our climb from a practice forced approach.
Last edited by RatherBeFlying; 16th May 2022 at 01:44.