Slider (parachuting)

A slider is a small rectangular piece of fabric with a grommet near each corner used to control the deployment of a "ram-air" parachute. A ram-air parachute has a tendency to open very rapidly. At high velocities, the opening shock from such a rapid deployment can cause damage to the canopy or injury to the jumper. The slider was developed as a way of mitigating this. During deployment, the slider slides down from the canopy to just above the risers. It is slowed by air resistance as it descends and reduces the rate at which the lines can spread and therefore the speed at which the canopy can open and inflate.^[1] This invention solved the rapid deployment problem with ram-air designs. Sliders also reduce the chance of the lines twisting to cause a malfunction.

In BASE jumping, when a rapid canopy deployment is desirable, the slider may be constructed of mesh, packed at a lower position on the lines ("slider down") instead of up by the canopy, or removed completely.

References

http://adventure.howstuffworks.com/skydiving4.htm

http://www.basejumper.com/Articles/Gear/Sliders_673.html

http://www.skydivewestpoint.com/skydiving-information/Soft-Parachute-Deployments.aspx