What is the influence of ground effect on landing distance?

• A. Decreases
• B. Increases
• C. Depends on approach speed
• D. No effect

Answer: (B)

Ground effect means the wing is very close to the surface, so lift increases and induced drag decreases for a given airspeed. On final approach, that extra lift makes the airplane float more and touch down later than it would in free air. Because you touch down further along the runway, you need more distance to decelerate and stop. So the overall effect is an increase in landing distance. The extent of the float can vary with approach speed and configuration, but the general tendency is longer landing distance.