Certified Flight Instructor - Flight Instructor Airplane Practice Exam

What causes adverse yaw during an aircraft's turn entry?

1. Increased induced drag on the lowered wing.

2. Decreased induced drag on the raised wing.

3. Increased parasite drag on the raised wing.

4. Both A and B.

The correct answer is: Both A and B.

Adverse yaw occurs when an aircraft enters a turn, causing it to roll to one side while yawing in the opposite direction. This phenomenon is primarily due to the differential lift and drag experienced by the wings during a turn. When a pilot initiates a turn, the aileron on the wing moving downward (the lowered wing) is deflected downward, which increases its lift but also increases its induced drag due to the increase in angle of attack. Conversely, the aileron on the other wing (the raised wing) is deflected upward, reducing lift and, consequently, reducing its induced drag, as the angle of attack decreases. This combination of increased induced drag on the lowered wing and decreased induced drag on the raised wing leads to a situation where the aircraft yaws toward the wing with the increased drag. Since adverse yaw is a result of the changes in drag on both wings during the turn, recognizing that both increased induced drag on the lowered wing and decreased induced drag on the raised wing are contributing factors validates why the answer encompasses both aspects. Including these elements together provides a complete understanding of the mechanics behind adverse yaw, clarifying how changes in drag arising from the aileron inputs affect the aircraft's yaw during a turn.