Using Ground Effect

The lack of respect many pilots give to ground effect sort of makes it the Rodney Dangerfield of aerodynamics. Its that momentary sag right after takeoff, and that little bit of float on landing. We know about it, but its often an afterthought: Oh, thats how I screwed up that flare. We all should know ground effect is only encountered...well, close to a flat surface, be it liquid or solid, but sometimes we forget.

Editorial Staff

Friday, September 25, 2015 at 12:00 AM ET

Verified

Key Takeaways:

Ground effect is an aerodynamic phenomenon where an aircraft experiences a reduction in induced drag when flying very close to a flat surface, caused by the deflection of the wing's downwash.
This drag reduction improves aircraft performance, making it particularly useful for operations like soft-field takeoffs, where pilots can get airborne at lower speeds and accelerate in ground effect.
Leaving ground effect during climb increases induced drag and thrust requirements, while entering it for landing reduces drag, enabling slower touchdown speeds but also causing changes in stability and indicated airspeed.
Effectively utilizing ground effect demands a gentle and anticipatory touch on the controls, as performance and control effectiveness change significantly when entering or leaving this low-altitude environment.

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The lack of respect many pilots give to ground effect sort of makes it the Rodney Dangerfield of aerodynamics. It’s that momentary sag right after takeoff, and that little bit of float on landing. We know about it, but it’s often an afterthought: “Oh, that’s how I screwed up that flare.” We all should know ground effect is only encountered…well, close to a flat surface, be it liquid or solid, but sometimes we forget.

Ground effect is a result of an airfoil’s so-called “downwash” changing velocity when a solid surface is close by. But how do we use it, and why? Any instructor worth his or her E-6B teaches students how to use ground effect on takeoff, especially from soft fields, so we all should know the basics. We can use it for other operations, too, and for other purposes.