Gain-Scheduled Pitch Autopilot (2D)

A pitch-attitude-hold autopilot commands the elevator to track a commanded pitch angle, but the aircraft's own control power changes with dynamic pressure — the same elevator deflection produces a much bigger pitching moment at high speed near sea level than at low speed high up. This 2D companion runs a fixed-gain PD controller and a dynamic-pressure gain-scheduled controller side by side on identical short-period pitch models, both driven by the same commanded pitch and the same airspeed/altitude flight condition, so you can watch the fixed-gain aircraft overshoot and oscillate at high speed (or go sluggish at high altitude) on a live strip chart while the gain-scheduled aircraft tracks the same command with consistent, well-damped response everywhere in the envelope.