Which set of factors does the TAD use to compute rudder trim input?

• A. Engine torque, airspeed, altitude, and pitch angle
• B. Altitude, airspeed, pitch rate, and propeller RPM
• C. Engine torque, rudder pedal, control forces, and altitude
• D. Engine torque, airspeed, altitude, and pitch rate

Answer: (D)

The TAD determines rudder trim by looking at four signals that reflect both steady yaw tendencies and how those tendencies change in flight. Engine torque is included because the engine’s power and torque create yaw moments, especially with unequal thrust or during high-power settings. Airspeed matters because it changes how effective the rudder is at producing a yawing moment. Altitude influences air density, which alters tail-plane and rudder effectiveness and thus the trim needed. Pitch rate provides a dynamic measure of how quickly the aircraft’s pitch is changing, which is linked to how yaw and roll couple in flight; using rate helps the system anticipate and counteract those cross-coupled effects. Together, these inputs give the most reliable basis for a stable, automatic rudder-trim command, keeping the aircraft balanced with minimal pilot effort.