What does "ground effect" refer to in aviation?

"Ground effect" in aviation refers to the increased lift and decreased drag that an aircraft experiences when it is flying close to the surface of the Earth. This phenomenon occurs when an aircraft is within a distance approximately equal to its wingspan from the ground. In this position, the airflow around the aircraft is affected by the surface, leading to a reduction in induced drag and an increase in lift.

As the aircraft gets closer to the ground, the pressure difference created by the wings allows for more efficient performance, which is especially beneficial during takeoff and landing. Pilots need to be aware of ground effect, as it can influence the handling characteristics of the aircraft during these critical phases of flight, allowing for smoother landings and shorter takeoff distances.

This understanding helps pilots manage their approach and landing speeds appropriately, ensuring that they remain safely above the aerodynamic limits as they transition through ground effect.