The rotor speed governor maintains rotor RPM within limits by automatically adjusting which cockpit control?

• A. Engine power output.
• B. Throttle position.
• C. Collective pitch.
• D. Tail rotor input.

Answer: (C)

The system keeps rotor speed by changing how much each rotor blade is pitched, i.e., by adjusting the collective. The governor watches the rotor speed (Nr) and makes small automatic changes to blade pitch to hold Nr within limits. Increasing collective raises blade pitch, increasing rotor drag and load; the engine then supplies more power to keep Nr steady. Decreasing collective reduces drag so Nr can rise back toward the reference. The other controls don’t directly regulate rotor speed in this automatic way: engine power output is adjusted indirectly to support the change, tail rotor input controls yaw, and there isn’t a separate throttle control used here in the same way.