What is the primary reason for entering a spin?

The primary reason for entering a spin is stalling at a high angle of attack. A spin occurs when an aircraft exceeds its critical angle of attack, leading to an aerodynamic stall. At this point, one wing may start to stall more than the other, causing the aircraft to enter a state of autorotation. This is characterized by a yawing motion towards the stalled wing, resulting in the aircraft descending in a tight, spiraling path.

Understanding this concept is essential for pilots, as it emphasizes the importance of maintaining proper speed and control during flight maneuvers, especially when approaching steep angles or executing turns. Other options, while they may lead to loss of control in different contexts, do not specifically lead to a spin in the same direct manner as exceeding the critical angle of attack and inducing a stall.