Wing Angle of Attack

The airfoil angle of attack is the angle between the chord line of an airfoil and the direction of the relative wind. The angle of attack is a critical aspect of aircraft performance, as it affects the lift generated by an airfoil and plays a key role in determining an aircraft's stability and control.

The airfoil angle of attack can be either positive or negative, and each has different effects on the lift generated by an airfoil. A positive angle of attack refers to the angle between the chord line of an airfoil and the direction of the relative wind when the airfoil is pitched upward. A negative angle of attack refers to the angle when the airfoil is pitched downward.

In aircraft design, the angle of attack must be carefully considered to ensure safe and efficient flight, taking into account the weight of the aircraft, the airspeed, and the desired flight characteristics such as takeoff and landing performance, cruise speed, and climb rate. The angle of attack can be adjusted by the pilot through the control surfaces on the wing, such as flaps and slats, or through changes in the pitch of the aircraft.

Positive Angle of Attack

A positive angle of attack results in lift generation as the air that flows over the curved upper surface of the airfoil moves faster than the air that flows over the flat lower surface, creating a pressure difference that lifts the airfoil. The amount of lift generated is directly proportional to the angle of attack, up to a certain critical angle where the air flow over the wing becomes disrupted and results in a loss of lift, known as a stall.

Negative Angle of Attack

On the other hand, a negative angle of attack can result in a loss of lift and increased drag. At high angles of attack, the flow separation over the airfoil can lead to a stall, where the air flow becomes disrupted and results in a sudden drop in lift. This can be dangerous for an aircraft, as it can result in a loss of control and a potential crash.

Posted February 4, 2023