Flight in known/knowable turbulence

In Early July at about 0900 an intermediate rated paraglider pilot impacted the ground on the east end of the South Side soaring ridge.  The pilot reported that earlier the wind meter behind and above the ridge reported 20-25 SSE.  The pilot was flying a 13 meter zero for the first time.  The pilot was flying east of the main gash and turning to the west when a large collapse occurred on the left side of the glider.  Despite weight shifting to the open side the collapse rotated the pilot around and into the hillside.  After the incident the trimmers were found to be set differently with the right trimmer at trim and the left fully let out.  The pilot reported that other pilots also concurred that the conditions were “weird.”

Strong winds from the east (20-25 SSE) have long been known to cause turbulent conditions at the South Side.  Even before construction of all of the homes in front of the ridge this has been the case.  If you look SSE of the ridge you will see small hills not too far away out in front of  the ridge.  They are far enough away to be overlooked by most pilots.  Nonetheless, mechanical turbulence is known to reach as far as 10 times the height of objects downwind of those objects.  The stronger the wind the farther the turbulence reaches.  Turbulated winds in excess of 20 mph is more than enough to cause a serious collapse in even a mini wing. 

The wind meter at the south side is more that 50 feet above the ground and does not measure the compressed wind speed found just out from the edge of launch.   It is likely that the wind that collapsed this glider was in excess of 25 mph. 

Flying in strong winds is an advanced skill.  Many advanced pilots will not fly when conditions are as strong as cited in this incident.

From the UHPGA website safety briefings for the South Side:

Known Hazards:

Strong east wind rotors off the hills south-east of launch and become turbulent enough to collapse paragliders.

From the Book of Risk:

How to avoid it.  (Flying in known turbulence)

Study the weather a lot, read a lot of books about weather especially related to paragliding and hang gliding:

Understanding the Sky by Dennis Pagen

Thermal Flying by Burkhard Martens

Mastering Thermaling by Kelly Farina

Weather for Dummies

Talk about the weather to other pilots you fly with.