Line Twists

[mknutson]

Line Twists: Line twists occur most often with skydiving rigs and can render canopies un-steerable and un-landable. Many Bridge Day injuries have occurred to jumpers who were unable to clear line twists and landed in the rocks or trees.

Cause

Bad body position on opening, often head down. You can also get into line twists from being head high as well. I have seen that if you are head high, and have a good 90deg or more off heading, your axis is prone to faster rotation in the direction of the off heading, and you can continue to rotate into line twists due to that momentum.

Prevention

Practice BASE exits into a swimming pool until comfortable. Jumpers can also insure that their eyes remain fixed on the horizon while exiting.

Cause

The most common cause is packing a skydiving canopy in a bag, which can tumble when pulled out of the container at low airspeeds.

Prevention #1

[][/] the skydiving canopy in the container if a tail pocket has been sewn into the tail of the canopy.

Prevention #2

Use a BASE specific container in order to reduce the chances of line twists. Regardless, line twists can be cleared by kicking your legs and pulling the risers apart.

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Maintain a flat or slightly head high position during deployment to reduce the chance of your canopy or canopy bag snagging on the container and spinning during deployment. Regardless, line twists can be cleared by kicking your legs and pulling the risers apart. Don't give up! If unable to clear the line twists, jumpers can "climb" up the lines and pull on the rear line groups to attempt to steer the canopy from danger. High-performance canopies and canopies with higher aspect ratios (9-cells) are much more likely to have line twists than 7-cell or BASE specific canopies.


This video shows the beginning attempts to steer a parachute in line twists

Dealing with Line Twists

The most important rule in any incident:
Get away from the Object!!!!!
You do not want to hit the object, and turning your canopy to avoid object strike MUST come BEFORE getting out of line twists.



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