What is ground effect?

Ground effect refers to the phenomenon where an aircraft experiences a reduction in induced drag and an increase in lift when flying close to the ground. This occurs primarily due to the interference of the surface of the Earth with the airflow patterns around the aircraft. As an aircraft approaches the ground, the air pressure builds up under the wings, resulting in a cushion that enhances lift.

This effect is particularly pronounced during takeoff and landing, where the aircraft is flying at lower altitudes. The presence of the ground disrupts the vortices produced by the wings, leading to more efficient lift generation when the aircraft is within a certain height, typically about one wingspan above the surface. Understanding ground effect is crucial for pilots, as it affects landing approaches, takeoff performance, and overall handling of the aircraft during low-altitude operations.

The other options do not accurately capture the essence of ground effect. For instance, turbulence caused by wind is a separate phenomenon; aerodynamic losses during descent typically refer to situations outside the influence of ground effect; and a sudden increase in lift is not the defining characteristic of ground effect, as the increase in lift occurs gradually as the aircraft descends into this influence.