PLT509: Wake Turbulence
What code PLT509 covers, why the FAA tests it, and how to study Wake Turbulence before your checkride.
Recall wake turbulence - characteristics / avoidance techniques
What this means for your checkride
Wake turbulence is the pair of counter-rotating vortices trailing from a wing making lift, strongest behind a heavy, clean, slow aircraft. The vortices sink and drift, so avoidance means staying above and upwind of a preceding aircraft's flight path.
Wake turbulence can roll a light aircraft beyond its control authority, so the FAA tests where the vortices go and the techniques to stay clear.
Pilots assume the wake stays on the centerline. The vortices sink and drift with the wind, so the timing and geometry of a takeoff or landing behind a heavy matter.
Where to study it
Practice questions on this code
Real questions from the Aviator IQ bank that test this exact area. Answer each to see the correct choice, the full rationale, and the FAA source.
Wingtip vortices from a generating airplane are greatest under which condition?
The strength of an airplane's wingtip vortices varies in what way?
Oral checkride defense
A code on your report is an area the examiner can revisit. Here is how an examiner might probe it, and how to explain it out loud.
Where are wake vortices strongest, and how do you avoid them landing behind a heavy?
Vortices are greatest when the generating aircraft is heavy, clean, and slow. Landing behind a heavy, I stay at or above its flight path and land beyond its touchdown point, because the vortices sink and drift with the wind.
You are departing behind a large jet. What is your plan?
I note its rotation point and plan to lift off before it, staying upwind and above its climb path, or I wait the advised interval. Vortices sink several hundred feet per minute and drift downwind, so I avoid the area below and downwind of its path.
A code on your test report is an area of deficiency. An authorized instructor must review it with you and endorse that review before you take the practical test, and the examiner may revisit it during the oral. Study it until you can explain it out loud, not just recognize the answer.