Floating due to ground effect during an approach to land will occur when?

Floating due to ground effect during an approach to land occurs primarily when an aircraft is flying at a low altitude above the runway, typically when it is less than half the length of the wingspan above the surface. Ground effect is a phenomenon that occurs as an aircraft approaches the ground, where the airflow around the wings is affected by the proximity of the ground, resulting in increased lift and decreased drag. This effect is most pronounced when the aircraft is just above the ground, which is why the specified height is crucial in experiencing floating during landing.

The situation described in the correct answer reflects the dynamics of lift generation in close proximity to the ground. When the aircraft is less than half a wingspan's length from the surface, it tends to maintain higher lift than what is required, causing the aircraft to "float" along the approach path instead of descending as expected. This can lead to landing delays or the need to manage touchdown more carefully.

Other factors such as stall speed or an increased angle of attack do not directly cause floating due to ground effect. While being close to stall speeds may impact performance, it does not specifically relate to the effect of flying near the ground. Similarly, a higher than normal angle of attack affects lift generation but is not the primary reason