What occurs to the downwash when an aircraft enters ground effect?

When an aircraft enters ground effect, the behavior of the airflow around the wings changes notably. Ground effect is a phenomenon that occurs when an aircraft is flying close to the ground, typically within a wingspan's height above the surface. In this condition, the downwash, which is the downward flow of air generated by the aircraft's wings during flight, decreases significantly as the aircraft approaches the ground.

This reduction in downwash occurs because the ground interrupts the airflow pattern. The presence of the ground creates an increase in pressure beneath the wings, which essentially compresses the airflow and reduces the amount of air that is deflected downward. As a result, the lift produced by the wings increases, and the overall aerodynamic efficiency of the aircraft is enhanced. This explains why the correct answer emphasizes that the downwash does not remain the same; rather, it is affected by the proximity to the ground.