Which of the following is NOT a factor that causes turbulence?

In the context of aviation, turbulence refers to the chaotic and irregular movement of air that can affect an aircraft during flight. Turbulence is typically caused by various atmospheric conditions and phenomena.

Stable air, characterized by a consistent temperature and minimal vertical movement, does not create the kind of disturbances in airflow that lead to turbulence. In contrast, factors such as wind shear (which involves a sudden change in wind speed or direction), jet streams (fast flowing air currents high in the atmosphere), and mechanical disturbances (caused by obstacles like mountains or buildings that disrupt airflow) are known to induce turbulence.

Therefore, stable air remains calm and is not conducive to the turbulent conditions that pilots must navigate during flight. Understanding the conditions that lead to turbulence is crucial for pilots and is an important aspect of safe flying practices.