AirlockPosted Monday, November 8, 1999
By Brian Germain
There is a considerable amount of chatter about “valved” parachutes going around these days. Many skydivers believe that airlocked parachutes are the way of the future, while others see the introduction of this new technology as a temporary fad. In this article I will discuss the pros and cons, as objectively as I can, to this new development in parachute design.
Simply put, an “Airlock” is a system designed to contain the internal pressure of a ram-air canopy, and therefore its airfoil shape. In short, the air goes in, but it doesn’t go out. If the wing’s shape is not reliant upon the relative wind (created by airspeed), then the performance range is consequently expanded and enhanced in every respect. In addition, the theory holds, such a self-contained airfoil will not distort or be otherwise adversely effected by turbulent flying conditions.
Parachute designers have worked towards the goal of a valved parachute since the very birth of the ram-air canopy. Domina Jalbert, the man to whom credit is given for developing the world’s first ram-air canopy, was among the first to design such a system. Although his “valve” didn’t exactly revolutionize the industry, the spirit of Jalbert’s concept of a self-contained airfoil continued to possess (and obsess) the minds of inventors worldwide. Some twenty years later, I too got enthralled with this quest.
I got involved with the airlock project as the result of a near-fatal collapse of my paraglider in 1993. From my wheelchair, I began designing various systems to keep the air in the wing, with mixed success. I built scores of miniature parachutes, experimenting with every type of valve I could imagine. I discovered that regardless of the type of valve, I had to retain the leading edge “scoop” of the airfoil in order to maintain adequate internal pressure. I realized that there are many ways to achieve this end, but found only one method that stood head-and-shoulders above the rest. So I brought my idea to the only person I could think of that might be crazy enough to actually build it: Tony Uragallo. He hired me on the spot.
Tony and I did extensive research on the valve concept over the course of three years. Some of our designs were incredible, while others weren’t worth the fabric we built them out of. It was an age of synthesis, a time of wild creative genius and misdirected insanity. We eventually developed a product that we were proud of, and marketed it as “The Jedei”. As expected, the market received it with mixed emotions. Now that there are literally hundreds of these canopies flying all over the world, the pros and cons of valved parachutes have become much more readily observable. The safety and performance advantages of the design seem to be very well received. Pilots of valve parachutes have observed significantly longer landing surfs, even without dangerous acceleration maneuvers. This is due to the lack of “wing shrinkage” as the airspeed decreases. Furthermore, owners report that the wing feels far more stable in turbulence, exhibiting little or no spanwise compression, even in the nastiest of conditions. The most exciting news is what has not been reported: there have been no documented canopy collapses due to turbulence whatsoever...Not One.
Clearly the primary objective has been achieved. Consequently, a valved-parachute “cult” has formed; a sector of the skydiving population that refuses to jump anything that isn’t valved. Supporters of the movement shun the use of “open-celled” parachutes in much the same way as early Zero-P jumpers avoided F-111 canopies. Although the supporters are adamant, they all have reported similar shortcomings to the airlocks.
The disadvantages to the design seem to be born of the same attribute that attracts airlock customers in the first place... the air doesn’t come out of the wing, whether you like it or not. For instance, after landing on an excessively windy day, you may be in for a bit of a fight if you haven’t developed a technique for “downing” the parachute. No one has reported any injuries as a result of being dragged after landing, and the hassle is something the owners seem to be willing to trade for the performance gains. The bottom line is: "would you rather have a bit of struggle with getting the air out on the ground, or a whole lot of struggle getting it back in during flight?"
The drop zone packers usually have a bone to pick with the airlock concept as well. As the air tends to stay inside the wing longer, the airlocks sometimes require an extra step in the packing process. Most packers have adapted a technique of laying the parachute in a side-pack configuration, and then rolling their bodies across the canopy from tail to nose. Once most of the air is out, the parachute packs up the same as any Zero-P canopy. Although the packers’ gripe is valid, one must keep in mind that if it were solely up to the packers, we’d all be jumping F-111 parachutes.
Lastly, there is the issue of cutaways. It is true that a few people have lost their valved canopies after cutaways. An undeniable side-effect to the airlocks is that the parachute can sometimes drift further after a cutaway than an “open-cell” canopy. This is usually not the case, but the possibility does exist. Interestingly, all of the despondent owners have replaced their lost parachutes with new valved canopies, an unarguable sanction of the technology.
The final question still remains: “Is it all worth it?”... Is the theoretical safety margin afforded by parachute valve systems worth the new problems that they create? The fate of the airlock parachute remains in the hands of the skydiving community... the future is still to be decided. The airlock may be just another passing facet of the “Techno Fad”, or a permanent feature of the sport that will develop into the industry standard. As always, the direction and nature of the accepted technology is determined solely by the consumer, not the inventor.
Brian S. Germain
April 8, 1997
Also known as a competitive freeflyer and lecturer, Brian Germain is the CEO of BiG Air Sportz, a new Colorado-Based parachute manufacurer. An avid skydiver with over 5000 jumps, Brian is the sole Patentholder on the “AirLock”, (U.S. Patent 5,573,207).
The airlock technology is currently available through BiG AiR on a limited basis, and will shortly be available from Performance Designs, Inc., and Precision Aerodynamics, Inc once PD's exclusice license expires. Although the airlock technology available from BiG AiR is arguably significantly different from that licensed to Performance Designs, Precision has decided to wait until the expiration of PD's license (July 31) to release BiG AiR's line of canopies in the U.S.
Subject: Airlock Article by Brian
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