Wake Turbulence Avoidance

Private Pilot License (PPL) Notes

This section covers the concept of wake turbulence and practical tips for avoiding it during flight operations.

Understanding Wake Turbulence:

1. Wake turbulence is invisible, caused by a pair of counter-rotating vortices behind an airplane's wingtips, generated whenever a wing is developing lift.
2. It becomes hazardous when the airplane rotates for takeoff and ends only upon landing.
3. The strength of wake turbulence is determined by:
   1. Wing shape.
   2. Speed.
   3. Weight of the airplane.
4. Wake turbulence is strongest behind large, slow airplanes that are taking off or landing.
5. The turbulent rolling motion can exceed the control capability of smaller aircraft, posing significant danger.

Characteristics of Wake Vortices:

1. Vortices descend about 400 to 500 feet per minute.
2. They level off approximately 900 feet below the flight path of the generating airplane.

Avoiding Wake Turbulence During Takeoff:

1. Visualize the location of the wake turbulence and plan to avoid it.
2. When taking off behind a large airplane:
   1. Observe where the large airplane rotates (lifts off).
   2. Take off before that point.
   3. Climb above the large airplane's climb path.
   4. Turn away from the path of the generating airplane.
   5. If there is a crosswind, make the turn into the wind.
3. For intersection takeoffs:
   1. Be alert for large airplanes operating nearby.
   2. Their vortices could drift into your flight path.
4. Avoid crossing under a large airplane's flight path.

Avoiding Wake Turbulence During Landing:

1. When following a large airplane to land on the same runway:
   1. Stay above its flight path.
   2. Watch where it touches down.
   3. Land beyond that point.
2. If landing behind a large airplane on a parallel runway closer than 2,500 feet:
   1. Be aware of possible drift of vortices to your runway.
   2. Stay above the large airplane's flight path.
   3. Note where it touches down and land beyond that point.
3. If landing behind a large departing airplane on the same runway:
   1. Note where it rotates.
   2. Land before that point.
4. If landing on a crossing runway behind a large departing airplane:
   1. Watch where it rotates.
   2. If it rotates beyond the runway intersection:
      1. No vortices will have been generated on your runway.
   3. If it rotates before the intersection:
      1. Avoid flight under the large airplane's flight path.
      2. If unable to land before the intersection, plan to go around.
5. Allow at least three minutes to elapse before taking off or landing behind a large airplane to let the turbulence subside, if possible.

Avoiding Wake Turbulence En Route:

1. Avoid flying below and behind a large airplane's flight path.
2. If a large airplane is above you on the same track, either meeting or overtaking:
   1. Adjust your position laterally.
   2. Preferably move upwind.

Additional Tips:

1. Expect air traffic controllers to advise of possible wake turbulence.
   1. Whether they do or not, you are expected to adjust your flight path as necessary.

Remember, understanding wake turbulence and taking proactive steps to avoid it are crucial for safe flight operations, especially during takeoff and landing.