I do the exercise below with my stall/spin/upset students to simulate the disorienting effect of a wake-turbulence encounter. We perform 1-1/2 aileron rolls to inverted and then push and roll to recover to normal upright flight. The exercise is confusing at first, and the nose always drops well below the horizon during the “upset.” It’s a great way to help pilots understand what could happen if they were caught in a wintip vortex.
Wake turbulence caused by wingtip vortices is major hazard to small aircraft.
The wingtip vortices are a by-product of lift. You can find detailed information about wake turbulence in FAA Advisory Circular AC 90-23 and in the Aeronautical Information Manual (Chapter 7, Safety of Flight; Section 3, Wake Turbulence).