Explain the term "ground effect" in relation to aircraft performance.

Ground effect refers to the aerodynamic phenomenon that occurs when an aircraft is flying close to the ground, typically within a few wingspans of the surface. In this situation, the presence of the ground significantly influences the airflow around the aircraft, leading to an increase in lift and a decrease in drag.

As the aircraft approaches the ground, the airflow gets compressed between the wings and the surface, which reduces the risk of airflow separation over the wings. This effect allows the aircraft to generate more lift at lower airspeeds, which is particularly beneficial during the takeoff and landing phases. Pilots can experience a “floating” sensation during landing because the aircraft requires less speed to maintain altitude just before touchdown, making ground effect an important factor in flight operations near the runway.

This phenomenon enhances performance during critical phases of flight, whereas the other options describe unrelated concepts or misinterpret the nature of ground effect.