Certified Flight Instructor (CFI) Checkride Practice Test

Differential or Frise ailerons are designed to help reduce adverse yaw, which is an aerodynamic effect that occurs when one wing generates more lift (and thus more drag) than the other during a turn. These ailerons operate differently from standard ailerons; one aileron moves up, causing the wing to reduce lift and drag, while the opposite aileron moves down, increasing lift at that wing. The design helps to mitigate the yawing motion that can occur as the aircraft turns, allowing for more coordinated and smoother maneuvers.

This characteristic is critical for maintaining effective aircraft control and efficiency during turns, making differential or Frise ailerons an important feature in many aircraft designs. Other choices reflect different aspects of aircraft design and operation, but they do not pertain specifically to the primary function of these aileron types.