What is the effect of Extreme Turbulence on an aircraft?

Extreme turbulence is characterized by very severe and unpredictable movements of the air. In such conditions, the aircraft experiences rapid and significant changes in altitude and velocity that can make control difficult for pilots. The forces acting on the aircraft can exceed normal operating limits, leading to a situation where conventional flight control inputs may be ineffective. This level of turbulence can cause passengers and crew to be thrown against restraints, and could lead to substantial risks, including structural stress on the aircraft itself.

In contrast to the other options, which suggest either minor effects or manageable situations, extreme turbulence presents a unique challenge. It's essential for pilots to recognize the severity of extreme turbulence and to prepare for the potential inability to maintain stable flight control. Understanding this helps pilots prioritize safety and take appropriate action in such conditions, including diverting or changing altitude to regain smoother air.