Both differential ailerons and Frise ailerons act to remedy a problem called aileron drag (or adverse yaw). This is caused by uneven drag on each wing when ailerons are deflected into the airflow. The down-going aileron modifies the deflection of the airflow as it passes over the wing producing extra lift (which is what we want) and extra drag (which is what we don't want). The up-going aileron on the other hand produces less lift and less drag. The result is uneven drag that cause the nose of the aircraft to yaw away from the direction of turn. The pilot must counteract this by applying a larger rudder deflection into the direction of turn. This causes an unwanted increase in total drag acting during the turn. See attached images.

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Thank you so much for helping sir.
Cheers
Flo.

Hi bob,
I got a question regarding the shimmy damper that it prevents vibration? How?

Your help is greatly appreciated.
Cheers
Flo.