A parachute is like a little nylon machine with all of the parts designed for light weight, durability and as few problems as possible during deployment. Considering the speed at which a skydiver is typically free falling -- about 120 mph (193 kph) -- and the lack of options if something goes wrong, a parachute rig needs to be incredibly reliable.
There's a lot of popular interest in the fine art of parachute packing. It has all the elements of great drama -- a person is folding a piece of fabric and stuffing it into a very small bag, and there's another person whose life literally depends on that fabric unfolding properly. When a parachute deploys, it needs to:
- Unfold reliably, so the entire parachute inflates correctly
- Unfold consistently, so the skydiver knows what to expect when the parachute opens
- Unfold without twisting, so the skydiver is facing the right direction after deployment
- Unfold without tangling the lines
- Unfold at the right pace - If it unfolds too quickly, it can hurt the skydiver and/or damage the equipment.
The best way for a skydiver to make sure that all of this happens is to pack the parachute carefully and follow the manufacturer's folding instructions. Most experienced skydivers do their own packing, and it takes 10 to 15 minutes to do the job.
One of the things that makes modern parachute packing so interesting is the use of zero-porosity fabric. Zero-porosity means that the fabric has a coating so that air cannot move through it. Zero-P gives the canopy better performance, but it also means that it can be very hard to get all the air out of the parachute during folding.
Now let's take a detailed look at what happens when a parachute is deployed.