2-6 Wake Turbulence and Wind Shear

  1. DESCRIBE wake turbulence
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    • The spanwise airflow that moves around the wingtip creates wingtip vortices (spiraling masses of air that are formed at the wingtip when an airplane produces lift).
    • The vortex is created by the pressure differential above and below the wing.
    • These vortices flow backwards and can cause performance issues and structural damage to other aircraft.
  2. DESCRIBE the effects of changes in weight, configuration, and airspeed on wake turbulence intensity
    Strength of vortex depends on three main factors: Airplane weight, speed, and wing shape

    • Weight
    • A heavier plane must produce more lift and will have a greater pressure differential at the wingtip where the vortex is created.
    • The heavier the plane, the stronger the vortex.

    • Airspeed
    • Vortex strength has a direct correlation to induced drag.
    • The greater the induced drag, the stronger the vortex.
    • Induced drag is dominant at lower speeds, meaning a slower aircraft will have stronger vortices.
    • Faster aircraft will spread the vortices energy over a greater distance, reducing the effect of the vortex.

    • Configuration
    • If flaps are lowered, more lift is created at the wing root, which decreases the pressure differential at the wingtip.

    The greatest vortex strength occurs when the generating plane is heavy, slow, and clean.
  3. DESCRIBE the effects of wake turbulence on aircraft performance
    • Wake turbulence can cause loss of control caused because of induced roll.
    • Another hazard is the induced flow field. It is created by the interactions of both vortices resulting in a downwash, between the vortices, of up to 1500 feet per minute. It is particularly dangerous for planes descending at a low power setting.
    • They are particularly dangerous during takeoff and landing operations.
  4. STATE the takeoff and landing interval requirements for the T-6B
    • Takeoff
    • 2 minutes behind a heavy aircraft (>255,000 lbs)
    • 2 minutes behind a large aircraft (41,000-225,000 lbs)

    • Landing
    • 3 minutes behind a heavy aircraft (255,000 lbs)
  5. DESCRIBE procedure for wake turbulence avoidance during takeoff
    • Takeoff after large takeoff(C)
    • Minimum spacing (2 mins for heavy, large)
    • Ensure your rotation (nose off the ground) point is complete at least 300 feet prior to the larger airplane's point of rotation and conduct climb-out to remain above his flight path.
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    • Takeoff after large lands(D)
    • Minimum spacing (2 minutes)
    • Point of rotation forward of where the large aircraft's nose touched down.
  6. DESCRIBE procedure for wake turbulence avoidance during landing
    • Landing after large lands (A)
    • Minimum spacing (3 minutes)
    • Stay at or above the larger airplane's final approach path and land beyond its nosewheel touchdown point.
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    • Landing after large takeoff (B)
    • Minimum spacing (3 minutes
    • Ensure that your touchdown point is prior to the larger aircraft's rotation point
  7. DEFINE wind shear
    A sudden change in wind direction and/or speed over a short distance in the atmosphere.
  8. DESCRIBE procedures for flying in and around wind shear
  9. DESCRIBE wind shear avoidance techniques
Card Set
2-6 Wake Turbulence and Wind Shear
Enabling Objectives