What does the Angle of Attack (AoA) refer to in aviation?

The Angle of Attack (AoA) in aviation refers to the angle between the chord line of an airfoil (like a wing) and the direction of the oncoming airflow, also known as the relative wind. This angle is crucial because it directly impacts the lift generated by the wing; as AoA increases, lift increases up to a critical point. Beyond this critical angle, if the AoA continues to increase, the wing may stall, resulting in a loss of lift.

Understanding the AoA is fundamental in aspects such as performance calculations, stall awareness, and the general principles of flight. It helps pilots to gauge performance and maintain control of the aircraft during various phases of flight, such as takeoff, cruising, and landing. It's important to recognize that AoA does not refer to the angle between the wing and the ground or any other reference points outside of the airflow direction, which is why this option correctly identifies the concept being discussed.