How does the stall progress in a rectangular wing?

The stall in a rectangular wing progresses outward from the wing root to the tip due to the way airflow behaves over the wing’s surface. As the angle of attack increases, the airflow begins to separate from the upper surface of the wing. This separation typically starts at the wing root, where the airflow has a higher velocity and greater lift.

As the angle of attack increases further, the stall moves outward towards the wingtip. This happens because the airflow over the root experiences a higher pressure difference which helps maintain flow longer, while the air at the wingtips encounters a more significant angle and ultimately separates sooner. Thus, the stall propagates from the root toward the tips.

Understanding this progressive nature of stall is critical for pilots as it affects control and handling characteristics during flight. Hence, recognizing that the stall starts at the root and moves outward helps address scenarios related to loss of lift and maneuverability as the aircraft approaches stall conditions.