Wake turbulence requires increased separation under which condition?

• A. Wake turbulence is turbulent air behind an aircraft; apply increased separation when following or preceding a heavy or super aircraft, especially on final or during takeoff/landing.
• B. Wake turbulence is gusts of wind created by ground vehicles; apply increased separation near the runway edge.
• C. Wake turbulence is airflow around wing tips; separation should be increased when aircraft are on final only.
• D. Wake turbulence is icing in clouds; increased separation during crosswind.

Answer: (A)

Wake turbulence is the turbulent air trailing behind an aircraft, caused by wingtip vortices. The strength of these vortices grows with the generating aircraft’s weight, so heavy and especially super aircraft create stronger wake. Because of that, when a lighter aircraft follows or precedes a heavy or super aircraft, there’s a higher risk of encountering those vortices. This risk is greatest during low-altitude phases like takeoff, landing, and the final approach, where aircraft are close together and speeds are slower, giving less time for the vortices to move away or dissipate. So, increased separation is required in these situations to reduce the chance of wake encounters. The other choices describe different phenomena that aren’t the wake turbulence hazard in this context.