Wake turbulence vortices may linger the longest over a runway under which wind condition?

• A. Light quartering tailwind
• B. Calm wind
• C. Strong headwind
• D. Moderate crosswind

Answer: (A)

The main idea is that wake turbulence dissipates most slowly when winds are light and there isn’t a strong breeze to move or mix the vortices away from the runway area. A light tailwind component, especially when the wind is quartering (from behind and to the side), tends to carry the vortices along the runway and keep them over the critical area longer, rather than pushing them clear of the approach or departure path.

With a calm wind, there’s little horizontal movement, but the vortices still dissipate over time through atmospheric turbulence; the tailwind adds a steady advection that keeps them in the hazardous zone longer. A strong headwind pushes the vortices away from the runway more quickly, reducing linger, while a moderate crosswind mixes and disperses them laterally, also reducing the time they remain above the runway. So the light quartering tailwind creates conditions that let wake vortices linger longest over the runway.