A byproduct of lift is a rotating spiral of air that is attached to the wing and travels with the airfoil. At the wing-tips, the vortex, sometimes called wake turbulence, is shed and produces a net descent relative to the air around it. The slower or heavier an air- craft, the more air it must redirect, and the larger the circulation in the vortex. The vortex, like a thermal, is subject to the air around it and can drift with the air-mass for a significant distance. Care should be taken when flying a paraglider in the vicinity of other aircraft as vortices are equivalent to turbulence and can cause deflations. Vortices from powered aircraft and even tandem paragliders with relatively high wing loading can create strong wake turbulence.
Section Number
3