What term describes the angle between the chord line and the relative wind?

• A. Relative Wind
• B. Angle of Attack
• C. Camber
• D. Chord

Answer: (B)

The angle of attack is the angle between the wing’s chord line and the relative wind. The chord line runs from the leading edge to the trailing edge of the wing, and the relative wind is the airflow coming toward the airplane. This specific angle controls how the air flows over the airfoil and, in turn, how much lift is generated. As you increase the angle of attack, lift rises up to a point, but if you push beyond the critical angle, the airflow can’t follow the surface and stalls.

The other terms describe different things: relative wind is the actual airflow direction, camber is the curvature of the airfoil, and the chord is simply that straight line from front to back. None of those define the orientation between the wing and the oncoming air the way the angle of attack does.