Private Pilot Private Exam

What is ground effect in aviation?

1. The impact of turbulence on the aircraft

2. The interference of the surface of the earth with airflow patterns

3. The primary cause of stalling

4. A method for improving fuel efficiency

The correct answer is: The interference of the surface of the earth with airflow patterns

Ground effect refers to the phenomenon that occurs when an aircraft is close to the surface of the Earth, typically within about one wingspan's distance from the ground. In this proximity, the airflow patterns around the aircraft are significantly influenced by the presence of the ground or water surface beneath it. As an aircraft approaches the ground, the wings generate lift more efficiently due to the compression of air between the wings and the ground, reducing induced drag. This effect allows an aircraft to experience a better lift-to-drag ratio during takeoff and landing phases, thus enhancing performance. This is why understanding ground effect is essential for pilots, especially during landings and takeoffs, as it can lead to a false sense of security regarding altitude and climb performance while in this proximity to the ground. Knowing this allows pilots to understand how to manage their approach and landing more effectively, maximizing the benefits of ground effect while minimizing risks associated with it.