What is the primary cause of an inadvertent spin?

The primary cause of an inadvertent spin is exceeding the critical angle of attack. When an aircraft exceeds its critical angle of attack, the airflow over the wings begins to separate, which can lead to a loss of lift. If one wing experiences a greater loss of lift than the other, it can result in a yawing motion toward the wing that is still producing lift. This differential lift creates a stall on the wing with less lift, which can then lead to a spin as the aircraft enters an uncontrolled rotation around its vertical axis.

Understanding the context of this phenomenon is critical for pilots, as avoiding spins requires maintaining awareness of the aircraft's angle of attack and ensuring that it does not exceed the critical value, especially during maneuvers that might require higher angles of attack. Pilots must be trained to recognize the signs of an impending stall and to respond appropriately to recover before a spin develops.

While insufficient elevator control, improper weight distribution, and excessive speed can contribute to loss of control or poor handling characteristics, they do not directly lead to a spin in the same primary manner as exceeding the critical angle of attack does. Recognizing and managing angle of attack is, therefore, essential for flight safety.