Definition
The angle of attack at which a wing produces its maximum coefficient of lift. Beyond this angle, airflow over the upper wing surface separates and the wing stalls, regardless of airspeed, weight, bank angle, or power setting.
Plain English
The steepest angle the wing can meet the oncoming air before it stops producing enough lift to keep the airplane flying. Go past that angle and the wing stalls, no matter how fast you are going.
Context Anchor
You will see this term in stall awareness, slow flight, steep turns, and any discussion of why an airplane can stall at different airspeeds and attitudes.
Derivation
Critical' comes from the Greek 'krisis,' meaning a turning point or decisive moment. Here it marks the exact angle that separates flying from stalling — the turning point of the wing's behavior.
Why Pilots Care
Exceeding the critical AOA is what actually causes a stall, independent of airspeed, and remains a leading factor in loss-of-control accidents.
Grounding Statement
No matter the airspeed, attitude, or weight, the wing always stalls at the same angle of attack — the critical AOA.
Intuition Check
Critical AOA is not a specific airspeed, and it is not the same as pitch attitude. It is the wing’s angle to the oncoming airflow.
Example Sentence 1
The instructor reminded the student that the wing will stall at the critical AOA whether the airplane is in a level glide or pulling hard out of a dive.
Example Sentence 2
A stall can occur at any airspeed once the wing reaches its critical AOA, which is why the same airplane may stall at a lower speed in slow flight than in a steep turn.