Editor’s note: Last month’s issue included a cover story on wake turbulence and how we may encounter it even when our training suggests it shouldn’t be a factor in our operations. This article is a companion piece, featuring a deeper dive into wake turbulence characteristics and behavior to help us predict where it is and how to avoid it.
Wake turbulence is a mostly invisible and potentially violent byproduct of lift generation. When an airfoil passes through the atmosphere, a pressure differential is produced, with the lowest pressure over its upper surface and the highest underneath. While creating the lift we need, this pressure differential also causes air to roll up and over the wing tip, where it meets and generates a horizontally aligned, high-energy and invisible vortex—a horizontal tornado, if you will—trailing aft of the wing tip. Every aircraft depending on an airfoil to generate lift, including helicopters, generates these vortices while airborne.
