When the wing exceeds its critical angle of attack, what occurs?

• A. The airfoil's pitch moment becomes zero
• B. Center of gravity becomes unstable
• C. The airplane accelerates uncontrollably
• D. A stall occurs

Answer: (D)

Pushing past the critical angle of attack causes the wing to lose its ability to generate lift because the airflow can no longer follow the wing’s surface. This flow separation creates a turbulent wake, so lift drops off dramatically while drag rises. The airplane will tend to descend unless you lower the nose to reduce the angle of attack and, if needed, add power to regain airspeed and reattach the flow.

Other options aren’t describing what happens: the pitching moment isn’t inherently zero at stall, and the center of gravity doesn’t become unstable simply from exceeding the critical angle of attack. The stall isn’t a situation where the airplane accelerates uncontrollably; typically, lift is lost and speed management becomes critical. The correct outcome is that a stall occurs.