A phenomenon that occurs when an aircraft develops lift and forms a pair of counter-rotating vortices. (PCG definition).
Wingtip vortices that are created when an airplane generates lift. When an airplane generates lift, air spills over the wingtips from the high pressure areas below the wings to the low pressure areas above them. This flow causes rapidly rotating whirlpools of air called wingtip vortices or wake turbulence. (PHAK definition)