What is the definition of the airplane angle of attack?

The angle of attack is defined as the angle between the wing's chord line and the oncoming relative wind. This is a critical concept in aerodynamics because it directly affects the lift generated by the wing. When the angle of attack increases, the lift produced by the wing generally also increases, up to a certain point. Beyond that point, known as the critical angle of attack, further increases can lead to stall conditions, where lift dramatically decreases.

Understanding this definition is essential for pilots, as controlling the angle of attack is fundamental to maintaining flight safety and performance. When pilots manage their aircraft's angle of attack appropriately during various phases of flight—such as takeoff, cruising, and landing—they can better manipulate lift and improve their overall flying efficiency.