Private Pilot Private Exam

In which flight condition is torque effect the greatest in a single-engine airplane?

1. High airspeed, low power, low angle of attack

2. Medium airspeed, high power, straight flight

3. Low airspeed, high power, high angle of attack

4. High airspeed, high power, level flight

The correct answer is: Low airspeed, high power, high angle of attack

Torque effect in a single-engine airplane results from the engine's rotational forces acting on the airframe, and it is most pronounced during specific flight conditions. The correct choice reflects a combination of low airspeed, high power, and a high angle of attack, which leads to an increase in the torque effect. When the airplane is operating with low airspeed and high power, the aircraft is typically producing a significant amount of thrust. This thrust, combined with a high angle of attack, increases the tendency of the airplane to roll in the opposite direction of the propeller's rotation due to the gyroscopic precession and the differential thrust on the wings. At lower airspeeds, the aerodynamic forces acting on the aircraft are reduced, meaning the reactiveness to torque effects becomes more pronounced. In contrast, conditions such as high airspeed or level flight can mitigate the influence of torque. For instance, in high-speed, level flight, the aerodynamic control surfaces are more effective, and the aircraft is less susceptible to rolling from torque forces since the flight dynamics and airflow become more streamlined. Thus, the influence of torque is less critical than it is during low-speed, high-power conditions.