Which control surface is specifically used to counteract yaw?

The rudder is the control surface specifically designed to counteract yaw, which is the rotation of an aircraft around its vertical axis. When a pilot needs to make a turn or correct an uncommanded yaw, they use the rudder to push the tail of the aircraft in the opposite direction of the yaw, helping to maintain coordinated flight.

Yaw can occur due to asymmetrical thrust, wind conditions, or other factors, and the rudder provides the necessary control to stabilize the aircraft. By controlling the yaw, the pilot ensures that the aircraft's nose points in the desired direction of travel, enhancing both safety and performance during flight maneuvers.

The other control surfaces—ailerons, elevators, and spoilers—play different roles; ailerons are responsible for roll, elevators control pitch, and spoilers can augment roll or reduce lift but are not directly involved in managing yaw.