Private Pilot License (PPL) Aerodynamics Practice Exam

What can be inferred about the stall angle for an aircraft?

1. It depends solely on the aircraft's weight

2. It varies with the aircraft's speed

3. It remains the same for a given airfoil regardless of conditions

4. It changes with different flap configurations

The correct answer is: It remains the same for a given airfoil regardless of conditions

The stall angle for an aircraft refers to the critical angle of attack at which the airflow over the wings becomes turbulent and the wings can no longer generate lift effectively. This angle is primarily determined by the design of the airfoil. For a given airfoil configuration, the stall angle is a fixed characteristic that does not change with different flight conditions. Therefore, stating that it remains the same for a specific airfoil regardless of conditions is accurate. Although factors like weight and speed influence the overall performance of the aircraft, including how and when the stall occurs, they do not alter the inherent stall angle of the airfoil itself. Changes in flap configurations can also affect overall lift characteristics and stall speeds but will not change the fundamental stall angle of the airfoil when flaps are either retracted or extended. Understanding this concept is crucial for pilots, as it allows them to predict and recognize stall conditions and handle the aircraft safely.