Wingtip vortices created by large aircraft tend to sink below the generating aircraft, causing turbulence to

• A. Rise above the lead aircraft
• B. Move forward
• C. Sink below the generating aircraft
• D. Drift sideways

Answer: (C)

Wingtip vortices are produced by lift and form two counter‑rotating streams that trail behind the aircraft. These swirling flows have a downward component, so they sink below the generating aircraft. As a result, following aircraft entering the wake will encounter turbulence in the air beneath the lead plane’s path, rather than above it, ahead of it, or off to the side. This downward sinking of the vortices is why wake turbulence is most problematic for aircraft in formation or in the downwind path at lower altitudes.