Which option correctly lists the four signals used by the FCCs to position the Stabilator?

Which option correctly lists the four signals used by the FCCs to position the Stabilator?

• A. They are four signals: Collective Position, Lateral Accelerometer, Airspeed, Pitch Rate
• B. Four signals: Altitude, Lateral Accelerometer, Airspeed, Pitch Rate
• C. Three signals: Collective Position, Lateral Accelerometer, Airspeed
• D. Two signals: Pitch Rate, Airspeed

Answer: (A)

Stabilator positioning is a feedback control that uses multiple flight-condition signals to determine the deflection needed for longitudinal stability and damping. Each input provides essential information about how the aircraft is being loaded and moving, so the FCCs can adjust the stabilator appropriately. Collective position matters because changing the collective alters rotor thrust and the nose-up or nose-down moment. The stabilator must counter that tendency to keep the aircraft on its desired pitch path. The lateral accelerometer gives a read on side-to-side loads and motion, helping the system sense and damp cross-coupled effects during turns or sideslips that would otherwise push the nose off target. Airspeed informs how much aerodynamic authority the stabilator has at the current speed, guiding the deflection to achieve the desired pitch moment without overreacting. Pitch rate provides rate information about how quickly the aircraft is pitching, allowing the system to apply damping to prevent overshoot and oscillations. If any of these inputs were missing, the stabilator would be slower to respond or less stable under dynamic flight conditions. Altitude, for example, isn’t directly used to compute stabilator deflection, and omitting either damping (pitch rate) or dynamic inputs (airspeed, lateral acceleration) would degrade stability and control.

Stabilator positioning is a feedback control that uses multiple flight-condition signals to determine the deflection needed for longitudinal stability and damping. Each input provides essential information about how the aircraft is being loaded and moving, so the FCCs can adjust the stabilator appropriately.

Collective position matters because changing the collective alters rotor thrust and the nose-up or nose-down moment. The stabilator must counter that tendency to keep the aircraft on its desired pitch path. The lateral accelerometer gives a read on side-to-side loads and motion, helping the system sense and damp cross-coupled effects during turns or sideslips that would otherwise push the nose off target. Airspeed informs how much aerodynamic authority the stabilator has at the current speed, guiding the deflection to achieve the desired pitch moment without overreacting. Pitch rate provides rate information about how quickly the aircraft is pitching, allowing the system to apply damping to prevent overshoot and oscillations.

If any of these inputs were missing, the stabilator would be slower to respond or less stable under dynamic flight conditions. Altitude, for example, isn’t directly used to compute stabilator deflection, and omitting either damping (pitch rate) or dynamic inputs (airspeed, lateral acceleration) would degrade stability and control.