Torque includes which of the following phenomena?

• A. Rotating slipstream
• B. All of the above
• C. Gyroscopic effects
• D. P factor

Answer: (B)

Torque on an aircraft caused by the propeller is a reaction moment that comes from several related effects, not just the engine’s turning force. The rotating slipstream—the swirling air behind the propeller—adds its own aerodynamic loading on the aircraft, contributing to the overall torque the airframe must balance. Gyroscopic effects arise because the propeller has significant angular momentum; when the aircraft’s pitch or yaw changes, the spinning propeller resists those changes and generates a reactive moment. P factor, the unequal loading of the propeller blades at high angles of attack, creates a net thrust and moment that also shows up as a torque on the airframe. Since all three phenomena can influence the torque experienced, all of the above is the best answer.