The angle between the airfoil's chord line and the relative wind is called what?

The angle between the airfoil's chord line and the relative wind is called what?

• A. Angle of Attack
• B. Angle of Sideslip
• C. Pitch
• D. Roll

Answer: (A)

The angle of attack is the angle between the airfoil’s chord line and the relative wind. This angle is what primarily controls lift: as you increase the angle, the airfoil deflects more air downward, producing more lift up to a critical point where the flow may separate and stall. It’s measured at the airfoil itself and is independent of the aircraft’s attitude, unlike pitch or roll, which describe orientation of the aircraft. The angle of sideslip, by contrast, is about the wind’s direction relative to the fuselage in the horizontal plane, not the airfoil’s blade. So the best term for the described measure is angle of attack.

The angle of attack is the angle between the airfoil’s chord line and the relative wind. This angle is what primarily controls lift: as you increase the angle, the airfoil deflects more air downward, producing more lift up to a critical point where the flow may separate and stall. It’s measured at the airfoil itself and is independent of the aircraft’s attitude, unlike pitch or roll, which describe orientation of the aircraft. The angle of sideslip, by contrast, is about the wind’s direction relative to the fuselage in the horizontal plane, not the airfoil’s blade. So the best term for the described measure is angle of attack.