Canopies for Skydiving
Canopies are the actual material of the parachute that opens above you and that allows you to descend to the ground at a faster or slower speed.
A larger sized canopy will allow you to descend slower and give you more control of your descent. The smaller the canopy, the faster you will descend and the more skilled and comfortable you need to be at descent. Finding the canopy that suits you is a personal preference but if you are a beginner, it is often suggested by the experts that you choose a larger canopy.
Having more control is important for beginners and intermediate skydivers. As you become more skilled and have at least several jumps under your belt and even a license, you can change your canopy preferences. More injuries occur to people who prefer smaller canopies for faster descent. Injuries most often occur because the new smaller canopy user thinks he has the same control of descent as he/she does with a larger canopy.
The fact is, the smaller canopy user is descending faster and needs to make more adjustments in his/her descent than with larger canopies. Smaller canopies are not always better even though there are many people today who love the thrills of faster descent.
Technically, a canopy should be chosen according to the jumper’s ‘exit weight’ – that is, your total weight after you have all your gear on and anything else you are wearing or carrying + 25 pounds. Your canopy has to be able to handle your exit weight and in fact, canopies are rated by exit weight. Many skydivers take extra care to make sure their canopies are proper for their weight.
One more factor that plays a big part in choosing the right canopy for you is called ‘wing loading’. The wing load is your exit weight in pounds divided by your canopy’s surface area in square feet. For example, a person weighing 180 pounds with a 180 square foot canopy would have a wing load of 1 pound per square foot. If the same 180 pounder got a 120 square foot canopy, his wing load would be 1.5 pounds per square foot (180 / 120 = 1.5).
A higher wing load increases the forward speed and descent rate of a canopy. The smaller canopy won’t be able to fly and glide as slowly as the canopy designed for the 1-pound per square foot canopy.
The smaller canopy turns more quickly, and loses more altitude in a turn thus giving the flyer less time to react to problems that may occur. A smaller canopy with a higher wing load will show up the weaknesses of the skydiver very quickly.
Canopies are designed individually by canopy designers like John LeBlanc who often design their canopies for certain effects they want. Different size canopies will fly differently even when flown with the same wing load. Certain effects will increase or decrease when you change from one design to another. It is often said for example that zero-porosity canopies will normally glide farther and flare better than ones made of low¬-porosity and larger “F-111” type material.
In order to help customers choose the right canopy, manufacturers publish wing loading recommendations for the canopies they build. Unfortunately, these recommendations are often misunderstood, and end up being used incorrectly. The bottom line of all this is that you must understand that there is no standard formula for determining a main canopy’s weight limit.
The numbers manufacturers give are usually numbers given to them from the designers who determine how their canopies should fly, and who often are the same people flying them. So think carefully before you go out and buy a canopy. Try it out if you can before you finalize the purchase.
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