What effect does induced drag have on aircraft flying close to the ground?

Induced drag is a form of aerodynamic drag that occurs as a result of lift generation. When an aircraft is flying close to the ground, it experiences a phenomenon known as ground effect. This effect occurs due to the presence of the ground beneath the aircraft, which alters the airflow around the wings.

As the aircraft approaches the ground, the airflow is compressed and the vortices that form at the wingtips are less effective, leading to reduced induced drag. This is because the wing is working more efficiently within this altered airflow environment, allowing for increased lift with lower amounts of induced drag compared to flying at higher altitudes where the vortices have more space to develop and create drag.

Thus, in this context, when an aircraft is close to the ground, the induced drag decreases significantly, making the correct option reflective of the aerodynamic principles involved.