Which term describes the tendency of the aircraft to turn opposite the direction of rotation of the engine and propeller?

• A. Torque
• B. Thrust Line
• C. Torquemeter
• D. Threshold Crossing Height

Answer: (A)

Torque is the twisting force created as the engine drives the propeller. Because of Newton’s third law, the airframe experiences an equal and opposite torque, so the airplane tends to rotate in the opposite direction of the propeller’s rotation. Pilots counter this with rudder input and, as needed, trim, especially during high-power takeoffs and climbs.

The other terms describe different ideas: thrust line is about where the thrust acts relative to the aircraft’s center of gravity, a torquemeter is an instrument that measures torque, and threshold crossing height is a performance point used during takeoff calculations.