What causes an aircraft to experience induced roll when flying into a vortex?

When an aircraft encounters a vortex, it experiences induced roll primarily due to downward turbulence caused by the vortex. Vortices are generated at the wingtips of an aircraft and create spirals of air that rotate downward and outward. When another aircraft flies through this region, particularly at low altitudes or in close proximity to the generating aircraft, the downward-moving air can disrupt the airflow over the wings of the encountering aircraft.

This turbulence can result in a differential lift, where one wing may gain more lift than the other due to the downward motion of the air. This imbalance produces a rolling motion toward the side of the aircraft affected by the vortex. As a result, the aircraft rolls in the direction of the vortex because one wing is subjected to increased lift while the other is experiencing reduced lift. This phenomenon is especially critical for smaller and lighter aircraft that are more susceptible to the effects of wake turbulence.

Understanding this mechanism helps pilots manage their flight paths more effectively to avoid the adverse effects of wake turbulence and maintain control of the aircraft.