Wingtip vortices are also referred to as wake turbulence.

• A. Boundary layer separation
• B. Induced drag
• C. Wake turbulence
• D. Thermal lift

Answer: (C)

Wake turbulence is the disturbed air left behind an aircraft as it generates lift, and wingtip vortices are the classic manifestation of that wake. When a wing creates lift, high-pressure air from below pushes around the wingtip to the low-pressure region above, curving around the tip and forming a pair of counter-rotating vortices that trail behind the airplane. These vortices can persist and spread, especially from heavier aircraft or at lower speeds, creating gusts and roll forces for following airplanes if they get too close. So the term wake turbulence specifically describes this trailing, turbulent air, with wingtip vortices being the most recognizable example.

Boundary layer separation involves the flow along the surface peeling away from the wing and is not the same phenomenon as trailing vortices. Induced drag is the pressure-difference drag that arises because lift is produced, not the vortical wake itself. Thermal lift refers to buoyant lift from rising warm air, unrelated to wingtip vortices.