Turbulence: The Invisible Hazard

Atmospheric turbulence can be a significant hazard when flying a ram-air canopy. It is important for all skydivers to understand the nature of turbulence and its potential effects on a canopy in flight. Skydivers should know how to avoid turbulence, but must also understand effective techniques for flying in turbulence if it is encountered. Some knowledge of basic aerodynamics is helpful when discussing turbulence: When flying a canopy you feel relative wind created by the movement of your body and canopy through the air. Lift is generated by the flow of relative wind around the canopy. The speed of this flow (airspeed) can affect the amount of lift generated by the wing. Angle of attack is the angle at which the relative wind intersects a particular section of a wing. As with changes in airspeed, changing the angle of attack can affect the amount of lift created. In normal flight the wing will have a positive angle of attack. If the angle of attack at a particular section of the wing reaches zero, that part of the wing will not create lift. An extremely high (critical) angle of attack will cause the wing to stall. A negative angle of attack can cause lift to be created in the “wrong ” direction. For example, aerobatic planes are able t