What is aerodynamic stall and what causes it?

Aerodynamic stall occurs when the angle of attack exceeds the critical angle (typically 14-18 degrees), causing flow separation from the wing's upper surface. This results in a sudden loss of lift and increase in drag. Stall is caused by the boundary layer's inability to follow the surface curvature against an adverse pressure gradient. Stall can occur at any airspeed depending on load factor and is characterized by buffeting, reduced control effectiveness, and potential loss of altitude.