What phenomenon is described by the term 'ground effect'?

Ground effect is a phenomenon that occurs when an aircraft is flying close to the ground, typically within one wingspan's height. In this situation, the wings generate more lift due to the interference between the air being deflected downward by the wings and the surface of the Earth. This lead to a compression of the air under the wings, which in turn enhances lift, making it easier for the aircraft to maintain altitude and control during takeoff and landing.

This increased lift can allow an aircraft to become airborne at lower speeds and reduce the stall speed while in close proximity to the ground, which is particularly beneficial during the critical phases of flight such as takeoff and landing. Understanding ground effect is essential for pilots to ensure safe operations, especially while descending and approaching to land.