When taking off or landing at an airport where heavy aircraft are operating, one should be particularly alert to the hazards of wingtip vortices because this turbulence tends to

• A. Sink into the flightpath of aircraft operating below the aircraft generating the turbulence
• B. Rise into the flightpath of aircraft above
• C. Move sideways away from the flightpath
• D. Stay at the same altitude

Answer: (A)

Wingtip vortices are the swirling, rotating air created by lift on the wings of a heavy aircraft. These vortex pairs generate a downward flow in their core and tend to descend as they move away from the aircraft. When you're taking off or landing near a heavy aircraft, this descending turbulence can reach the flightpath of aircraft operating below it, posing a hazard. It’s not rising into the path of aircraft above, nor moving primarily sideways, nor staying at the same altitude—the vortices naturally sink and can therefore affect aircraft below the generating airplane.