A stall in flight is primarily caused by what phenomenon?

A stall in flight occurs when the angle of attack—the angle between the wing's chord line and the oncoming air—exceeds a critical threshold, leading to a loss of lift. When the angle of attack becomes too steep, airflow can no longer smoothly adhere to the wing's surface, resulting in a sudden drop in lift. This critical angle varies depending on several factors, including the aircraft's configuration, speed, and environmental conditions.

The phenomenon of a stall is particularly significant in aviation as it occurs during critical phases of flight, such as takeoff and landing, where pilots are often operating at higher angles of attack. Understanding this critical angle is vital for pilots, as recognizing and avoiding conditions that lead to a stall is essential for maintaining flight safety.

While other options present scenarios that can affect flight dynamics, they do not directly lead to a stall in the same manner as an excessive angle of attack does.