How do Parachutes Work?
Parachutes were very amusing when you're a kid. They are common science projects at school. They are fairly easy to make and require only inexpensive materials. However in the real world, using a parachute while free falling has serious implications. If the parachute does not deploy at the right moment, the person can fall to their death.
Fortunately they have gone through developments and trials throughout the decades for safer landings. Understanding the principle behind a parachute is easy but understanding how parachutes work is essential. By knowing the correct sequence of deployment you'll know that you will be able to make it to the ground in one piece.
Parachutes are packed by the owners themselves or riggers. They must be packed properly so that they will deploy correctly. It would take a lot of effort to pack a parachute. Modern designs have zero porosity which means the air can't pass through the fabric, making harder to fold.
A reserve is also packed along with the main parachute in case something goes wrong. The reserve is also packed by rigger. Is taken out and repacked again every couple of months so that it won't get stiff.
In a normal situation the deployment sequence has steps. To start the sequence the skydiver pulls out the drogue chute. It's inside a little pouch placed at the bottom of the container or knapsack. When the drogue inflates it pulls the bridle.
The bridle is a nylon webbing which is ten to twenty feet long. This in turn pulls the closing pin. The pin holds the canopy. When the pin is pulled it gives out a small pop.
The other end of the bridle is connected to the deployment bag. The deployment bag contains the lines placed in a zig zag pattern underneath and the parachute. As the drogue and the bridle continue to pull upward, all the lines will be unfolded and stretch out. The line in turn, pulls out the risers as it continues to unfold. The risers have nylon straps that connect the lines and the parachute to the container which is carried by the skydiver.
The parachute is pulled out of the deployment bag by the tension in the lines. The wind then inflates the canopy. Modern designs called Ram-air parachutes have sliders. They hold the lines together and prevent the canopy from opening to quickly. If that opens it can cause a tear in the canopy and/or hurt the skydiver.
When the parachute is completely out and opened the skydiver can grab the toggles to be able to steer the parachute towards the landing site.
Unfortunately there is still the possibility of something going wrong. A part of the main canopy may not inflate or entirely at all, it may get tangled in the lines, rips or never comes out of the deployment bag. If any of this happens the skydiver can deploy the reserve.
You have to cut away the main canopy first to be able to do this. A release handle can be pulled out of your shoulder straps to cut away the main canopy.
After that, either the reserve deploys automatically due to the reserve static line. On other designs the skydiver has to pull out a second handle to release the reserve. Let's just hope in both of these cases he reserve deploys correctly.