Private Pilot License (PPL) Aerodynamics Practice Exam

What happens to lift as the angle of attack approaches the critical angle?

1. It increases significantly

2. It decreases gradually

3. It reaches a maximum

4. It remains constant

The correct answer is: It reaches a maximum

As the angle of attack approaches the critical angle, lift reaches a maximum value. The critical angle is the point just before airflow separation begins to significantly affect the airflow over the wing. At angles of attack lower than the critical angle, lift increases as the angle of attack increases, due to the greater airflow pattern around the wing, which generates more lift. However, once the critical angle is reached, the lift begins to level off and will not increase further; in fact, if the angle of attack continues to increase beyond this point, lift will decrease due to flow separation. Understanding this behavior is crucial for pilots because it highlights the importance of managing angle of attack during flight to avoid stalling, which occurs when the wing can no longer produce sufficient lift.