The Evolution Of Small

By Jim Slaton

Some of the top canopy pilots figured it out many years ago that a larger canopy at the optimal wing loading would go further than a smaller one. This is why the sport went from swoopers flying small parachutes as they could get their hands on to upsizing and strapping on extra weight. Team Extreme put this to the test almost a decade ago but the PDFT was the first to start using it it competition. Lets look at an example of why this works:

-A swooper has two canopies that are exactly the same except one of them is a 60sqft and the other is 111sqft. He is flying them both at the optimal wing loading of 2.5 (optimal loading is based off many things including wing type, wing shape, material, cell structure, etc).

Parachute wings like the wings of an aircraft (and all other types of wings) are designed so air flows faster over the top than the bottom. As the "velocity" of air increases the pressure decreases and the wing produces "lift" over the TOP of the wing. So to be clear you have low pressure above the canopy and high pressure below. If the high pressure from below the canopy gets around or through to the low pressure they can cancel each other out. Stabilizers are help reduce this.

When the canopy reaches max speed (from a dive, turn, etc) it carries its maximum "low" pressure over the wing in the form of "lift". If he is flying his 60sqft canopy then he has 60sqft of lift over the wing. If he is flying a 111sqft canopy then he has with 111sqft of lift over the wing, a big difference! Entering the swoop with more lift has its advantages including you can maintain level flight longer. As the canopy starts to decelerate it looses low pressure over the wing. Drag, airfoil distortion and pilot inputs determine how fast the canopy decelerates.

This is why larger parachutes come in slower than smaller canopies but they carry more lift allowing them to swoop further. It also allows them to make more inputs, more corrections and more mistakes. In contrast a small parachute comes in faster but runs out of steam (low pressure/lift) faster too! The VX46 demonstrated this in early 2000 as Luigi flew it in competition a few times getting his ass kicked by me :) Seriously, the 46 would come in much faster (and louder) than but it would slow down twice as fast too. It could only carry 46sqft of lift over the wing and the smallest input would create drag magnifying the deceleration process.

Its not an exact science since we are, in the words of skydiving's most successful parachute engineer, flying an object similar in shape to a mattress! There are limits on both ends of the spectrum as there is "too small" and there is "too big". If you fly a canopy too small you cannot carry enough lift over the wing, its too sensitive to inputs and hard to maintain your speed. If you fly a canopy too big it has too much parasite drag giving it trouble to maintain speed and a long list of other issues.

So the game in the second half of this decade was to fly the largest canopy possible at its optimum loading. So if you flew at 70sqft canopy at an optimal loading of 2.5 without any additional weight then you would throw on your maximum allowable weight and get the largest canopy you could fly but at the 2.5 loading. Before there was a weight control system in place there were swoopers flying 100+sqft canopies wearing 60+ pounds of extra weight! It had become a contest to see who could wear the most weight! I rushed to fix the problem with weight classes, not the current weight control rules. Don't limit, eliminate!

Generally speaking and with the canopies of today a larger canopy at the same optimal loading would swoop further. However, if the design of the canopy improves beyond the technology of today and the materials continue to improve we may see pilots flying much smaller canopies at the same loadings. The new technology would allow pilots to fly smaller wings and maintain performance from reducing parasite drag and maintaining lift.

This is exactly what happened in the hand gliding community over the past several decades as competitors winning with much larger gliders and ballast (extra weight) got replaced by smaller and better built gliders with no ballast. New designs, composites and materials gave gliders a better wing shape which gave them less drag and less distortion (less flow separation).

This is our future.

Sail material has done the same thing to parachutes but its only a small part of the equation for the next generation of high performance canopies. Sail material is thicker than ZP and has special coatings that allow the wing to hold its shape better during flight with less distortion/flow separation. This is the reason why JVXs made of all sail can be flow smaller than their ZP counterparts with equal or more performance. Just take a look at the two canopies setting the world records in distance. Nick Batsch is setting world records of 165 meters (541ft) flying canopies between 60 & 75sqft while jay Moledzki is setting a record of 175 meters (574ft) flying Velocity's between 80-111sqft.

The reason why sail material has not caught on with the rest of the market is because its large pack volume and high maintenance. These canopies cost more, pack larger and are harder to pack. The larger pack volume may even force some pilot to purchase a larger rig to fit the canopy.

Its funny because the two technologies that can take swooping canopies to the next level is going down the same road again. Tri-bracing technology was created a full decade before it actually caught on with skydivers because you guessed it....it packed bigger, cost more and was higher maintenance. Sound familiar? Skydivers went from Stiletto to a tri-braced canopies that packed 30-40% bigger! At first the skydiving community dismissed them as too specialized but in 1996 pond swooping was born which created a market for these specialized wings. These new canopies not only cost more (because it took more material and time to make them) but most skydivers had to purchase larger rigs in order to fly them. Oh, I forgot to mention, skydivers complained because they were harder to pack!

Sail material and Z bracing is the next generation of elite canopies.

Both cause greater packing volume and more maintenance. I have flown and tested the Z braced technology for over five years now. Certain guys in blue got their first glimpse of the Z braced technology in 2004 when they showed up at the Team Extreme room at Perris and saw the "JSX" laying on the team room floor. I was in the air and forgot to lock the door! Unlike current tri-brace canopies which divide each cell into three chambers the Z brace cell structure divides each cell into five chambers making the canopy even more rigid.

Fast forward to today.

Sail material is now taking that pack volume even bigger with tri-braced canopies and when the industry goes to Z brace they will pack even larger! Even if you build a Z braced canopy with all ZP it would still pack 20-30% larger then its tri-braced counterpart. Trust me on this. If you want the ultimate swoop canopy then you would make a Z braced canopy out of sail! Then you would have the best of both worlds. The canopy would have 4-5 times the rigidity compared to the canopies of today but it would pack 4-5 times bigger too!

Maybe not 5 times larger but you get the picture.

I own a 83sqft Z braced canopy made of ZP that packs like a 150 conventional and another made of sail that packs like a 190! So the competitive swoopers of the future will be wearing large CRW style rigs with little (60-80sqft) canopies:) There is no way around this at the moment which is one of the biggest reasons the industry is in no hurry to replace their current tri--braced wings.

P.S. The added rigidity gained using sail material was one of the contributing factors to the success of Luigi landing the JVX 37