Yaw is the third axis of control. Pitch moves the nose up and down. Roll tilts the wings. Yaw swings the nose left and right, and the rudder handles it. The hinged surface sits on the vertical stabilizer at the rear of the aircraft.

Pilots use rudder to coordinate turns, counteract adverse yaw from ailerons, and maintain directional control during crosswind landings. On multi-engine aircraft, rudder input is critical after an engine failure, when asymmetric thrust tries to push the aircraft sideways.

Common rudder uses

• Coordinating turns with ailerons
• Crosswind takeoff and landing
• Counteracting engine failure asymmetry
• Spin recovery

Rudder authority is limited. At low speed, full deflection may not be enough to counter a strong crosswind or a failed engine. That is why pilots compute takeoff and landing limits before every flight.