If VMCA is influenced by the absence of negative torque sensing, what is the recommended propeller setting?

• A. Feathered
• B. Full forward
• C. Half feathered
• D. Stowed

Answer: (A)

VMCA is affected by the drag produced by the windmilling prop on the inoperative engine. When there’s no negative torque sensing, you can’t rely on automatic adjustments to counter yaw and drag, so the best way to preserve controllability at the minimum control speed is to minimize that drag. Feathering the prop on the inoperative engine places the blades nearly parallel to the airflow, drastically reducing windmilling drag and the associated yaw moment. This helps keep VMCA higher and the airplane controllable with one engine out.

Full forward or half feathered keep the prop in a position that still causes significant drag and yaw, making control more difficult at the critical speed. Stowed isn’t a practical in-flight setting for most twin-engine prop airplanes and isn’t a feasible option in typical engine-out scenarios.