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Free PSTAR practice Wake Turbulence

What effect would a light crosswind have on the wing tip vortices generated by a large aeroplane that had just taken off? A light crosswind

  1. Acould cause one vortex to remain over the runway for some time.Correct answer
  2. Bwould rapidly dissipate the strength of both vortices.
  3. Cwould rapidly clear the runway of all vortices.
  4. Dwould not affect the lateral movement of the vortices.

Why this is the answer

Per TC AIM-AIR (Wake Turbulence / Vortex Characteristics), vortices spread laterally at about 5 kt, so a light crosswind can hold the upwind vortex stationary over the runway for some time (and push the downwind one toward a parallel runway) rather than clearing it.

Reference

TC AIM-AIR – Wake Turbulence / Vortex Characteristics / General

Question reproduced verbatim from Transport Canada’s PSTAR Study and Reference Guide (TP 11919E). The answer key is Transport Canada’s; the explanation is ours.

A study aid — not a substitute for the official guide, the CARs, or your instructor.

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