Angle of Attack: The angle measure between the ______ and the chord line.

Angle of Attack: The angle measure between the ______ and the chord line.

• A. Angle of incidence
• B. Resultant relative wind
• C. Total aerodynamic force
• D. Tip path plane

Answer: (B)

Angle of attack is the angle formed between the relative wind and the airfoil’s chord line. The relative wind is the airflow that the wing experiences as the aircraft moves through the air; it points opposite to the aircraft’s velocity. The chord line runs from the leading edge to the trailing edge of the airfoil. This angle directly controls lift: increasing it increases lift up to a critical point, after which the flow separates and a stall occurs. The other terms aren’t describing this angle—angle of incidence is the fixed angle between the wing’s chord line and the aircraft’s fuselage, the total aerodynamic force is a combination of lift and drag rather than an angle, and the tip path plane refers to rotor blade motion, not the airfoil’s angle of attack.

Angle of attack is the angle formed between the relative wind and the airfoil’s chord line. The relative wind is the airflow that the wing experiences as the aircraft moves through the air; it points opposite to the aircraft’s velocity. The chord line runs from the leading edge to the trailing edge of the airfoil. This angle directly controls lift: increasing it increases lift up to a critical point, after which the flow separates and a stall occurs. The other terms aren’t describing this angle—angle of incidence is the fixed angle between the wing’s chord line and the aircraft’s fuselage, the total aerodynamic force is a combination of lift and drag rather than an angle, and the tip path plane refers to rotor blade motion, not the airfoil’s angle of attack.