Turbulence and Wind Shear Flashcards
What is turbulence?
Small scale, short term, random and frequent changes to air velocity
What are the 5 main causes of turbulence?
- Convective
- Mechanical
- Orographic
- Frontal
- CAT
What is convective turbulence?
A rising heat source causing an obstruction to wind
What is mechanical/frictional turbulence?
Caused by physical obstructions such as mountains or buildings
What is orographic turbulence?
Mountain waves
What is frontal passage wind shear?
Changing wind directions at the point where 2 fronts meet
What is CAT?
Strong wind shear both horizontal and vertical, associated with Cb and mountain waves, can be severe and difficult to detect
What is wind shear?
When wind sped or direction changes within a shallow layer, vertical or horizontal
Where is wind shear common?
- Thunderstorms
- Microbursts
- Temperature inversion
- Valley inversion
- Friction layer
- Topographical
What are techniques to avoid wind shear?
- Holding
- Diverting
- Delaying take-off
How often are wind shear reports updated?
Every 1 minute
Who can report wind shear?
Pilots
What detects CAT?
Pilot reports
What is moderate turbulence?
Moderate changes in aircraft attitude and/or altitude, aircraft remains in control
What is severe turbulence?
Abrupt changes in aircraft attitude and/or altitude, aircraft may be out of control for short periods
