What is 'ground effect'?

Ground effect refers to the aerodynamic phenomenon that occurs when an aircraft is flying close to the ground, typically within a distance equal to or less than its wingspan. In this situation, the lift generated by the wings is increased while the drag is decreased. This occurs because the ground disrupts the airflow patterns around the wings, effectively reducing the induced drag that is typically present when the aircraft is operating in free air.

As the aircraft approaches the ground, the airflow under the wings is compressed between the wings and the surface, which increases the air pressure under the wings, thereby enhancing lift. This effect is particularly significant during takeoff and landing phases of flight when the aircraft is operating at lower speeds and is in closer proximity to the ground. Understanding ground effect is essential for pilots as it can influence landing and takeoff performance, requiring careful management of the aircraft's approach and departure profiles to ensure safe and effective operations.