Name a potential symptom of loss of hydraulic power to primary flight controls?

• A. Increased control responsiveness.
• B. No effect on handling.
• C. Uncommanded yaw only.
• D. Reduced controllability or degraded control feel.

Answer: (D)

Hydraulic power provides the force and feedback that moves and centers the primary flight control surfaces. When that power is lost, the actuators can’t move surfaces as commanded, so the controls feel heavy, become less responsive, and the aircraft’s authority is degraded. On the 787, primary flight controls rely on hydraulic actuators controlled by the flight-control system, so losing that power means you’ll notice reduced controllability and degraded control feel. The effect isn’t limited to one axis or a single symptom like uncommanded yaw; it affects multiple surfaces, making the airplane harder to maneuver and the stick feel less precise.