What is the adverse yaw in a turn?

Adverse yaw is a phenomenon encountered during an airplane turn where the aircraft yaws or turns away from the desired direction of the turn. This occurs because of differential lift and drag produced by the wings during a bank. When a pilot initiates a turn by banking the aircraft, the aileron on the wing that is rising (the up-going wing) deflects downwards, while the aileron on the wing that is descending (the down-going wing) deflects upwards. This differential control inputs creates more lift on the up-going wing, but it also increases drag due to the down-going aileron.

As a result, the wing that is generating more lift (the up-going wing) causes the aircraft to roll in the desired direction, but at the same time, the increased drag produces a yawing motion towards the opposite direction, creating the effect known as adverse yaw. This means the aircraft tends to yaw away from the direction of the turn, which can require the pilot to coordinate the use of the rudder to maintain a balanced turn. Understanding this concept is crucial for pilots, as it highlights the importance of coordinated flight control inputs to achieve smooth, effective turns.