FAA Ground School Practice Test

In which flight condition is torque effect most pronounced in a single-engine aircraft?

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

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

3. Cruise speed, moderate altitude, standard power

4. High airspeed, low power, neutral angle of attack

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

The torque effect in a single-engine aircraft is most pronounced during low airspeed, high power, and high angle of attack due to the combination of several aerodynamic and mechanical factors. When an aircraft is at low airspeed, the control surfaces are less effective, and the aircraft's responsiveness to any yaw-induced by torque becomes more noticeable. At high power settings, such as during takeoff or climb, the engine produces significant thrust, which amplifies the torque effect. This is because the rotation of the engine causes the aircraft to roll in the opposite direction. The greater the power setting, the more pronounced the torque effect becomes, leading to a stronger tendency for the aircraft to yaw to the left (in a conventional single-engine aircraft with a clockwise rotating propeller). Additionally, when the angle of attack is high, the airflow over the wings and control surfaces is altered, further reducing the effectiveness of ailerons and rudders. This makes maintaining controlled flight more challenging, as the torque effect can initiate a roll that needs to be countered with opposite aileron input. In combination, these conditions create an environment where the pilot must be especially vigilant to counteract the yaw introduced by torque, making this scenario the most critical for experiencing torque effect.