Basic Principle

The vortices generated at the wing tips of an airborne fixed wing aircraft, or from the rotors of a helicopter in forward flight, create transient rotational turbulence, which trails behind the aircraft in a descending and down wind direction, and may cause sudden uncommanded roll to affect a following aircraft, perhaps at a sufficient rate of roll to disconnect the autopilot if engaged. Light aircraft may also experience marked pitching moments when traversing a vortex from the side, such as when turning finals from base leg behind a larger aircraft.