What is the effect of drag from a down aileron during a turn?

When a down aileron is deployed during a turn, it increases drag on that wing. This additional drag causes the aircraft to yaw in the opposite direction of the turn. Specifically, if the left wing has a down aileron during a left turn, the increased drag on the left wing pulls the nose of the aircraft slightly to the right, opposing the intended direction of the turn. This yawing motion can disrupt the coordinated flight of the aircraft, requiring the pilot to use rudder input to counteract the induced yaw and maintain a balanced turn.

This phenomenon highlights the importance of coordination between ailerons and rudders during maneuvering, as uncoordinated flight can lead to adverse situations such as a stall or loss of control. Understanding the relationship between aileron position, induced drag, and resultant yaw is crucial for pilots to maintain effective control of the aircraft throughout the turn.