Certified Flight Instructor - Flight Instructor Airplane Practice Exam

If the same angle of attack is maintained in ground effect as when out of ground effect, lift will?

1. Increase, and induced drag will decrease.

2. Decrease, and parasite drag will increase.

3. Decrease, and parasite drag will decrease.

4. Remain constant.

The correct answer is: Increase, and induced drag will decrease.

When an aircraft is in ground effect, it experiences an increase in lift for the same angle of attack compared to when it is out of ground effect. This occurs because the proximity of the aircraft to the ground alters the airflow around the wings, reducing the strength of the wingtip vortices and the induced drag associated with them. In ground effect, the enhanced lift results from the interference of the ground with the airflow patterns that form as the wing generates lift. The reduction in the vortex strength leads to a more efficient lift generation at the same angle of attack. Additionally, as the induced drag decreases, this allows for an increase in efficiency during flight near the ground. Therefore, maintaining the same angle of attack while in ground effect allows the aircraft to generate more lift, while simultaneously decreasing induced drag, thus validating the correctness of the answer.