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be able to provide useful information on any problems with the local ridge. 

## Tips and Techniques 

Observe the ridges slope for collectors or dividers of the wind flow. Plan to determine which of the slopes is gathering wind flow. [Figure 10-26] Due to the changes in wind directions and or sun angles, any portion on the ridge can change in only a few minutes. 

• Collectors are mountain/ridge bowls and canyon ends that can offer extreme areas of lift when the wind is blowing into them. Remember to have a way out. 

• Dividers are ridges parallel with the wind and tend to have airflow separation. A collector that may be downwind from a divider may receive more airflow, making better lift possible. 

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The downwind side of any ridge or hill produces turbulence and sink. The larger or higher the ridge and the greater the wind velocity, the wider the turbulence may be. During these conditions, remember to ensure that seat and shoulder harnesses are tight. Sink calls for speed. Turbulence and speed are very hard on the glider airframe and pilot comfort. Pilots must obey glider limitations set forth in the GFM/ POH. Also, do not exceed the design speed for maximum gust intensity (V$_{b}$ ). [Figure 10-27] 

The ridge crest is where all airflow starts down. Steep ridges with narrow ridge tops can collect thermal action from both sides of the crest. The best lift could be directly above the crest. However, this terrain can be very hazardous as a pilot cannot see it or may not have visual cues. If wind is the only source of lift, the crest can be very dangerous. Always stay upwind of the crest. [Figure 10-28] 

Areas along the ridge that are in deep shade is where the air goes down and sink can be found. If there is strong lift on the sunny side of the ridge, then chances are that strong sink 

