billbooth

Pilotdave; What happened to you is getting more and more common. Although I hold the patent on the hand deploy pilot chute, I never charged anyone a royality to use it, and therefore never published construction details. I'm afraid this has led to some poorly made pilot chutes as people have copied, but not copied EXACTLY, my original design. As a matter of fact, last Sunday, a jumper came up to me, said that he was having "pilot chute hesitations" on his Vector, and asked me to have a look. His problem, it turned out, was the same one I've seen countless times before...His pilot chute was made by "God knows who", and made incorrectly. I don't know about you, but one of the the scariest malfunctions I can think of, is a streamered main pilot chute that has enough drag to open your main container, but not enough drag to lift out the bag. What do you do? If you just lie there and wait, the ground may "rise up to smite thee". If you pull your reserve, your main is going to simultaneously deploy, and main/reserve entanglements are rarely much fun either. What to do...Easy, don't jump an incorrectly manufactured or adjusted pilot chute. So, how can you tell if your hand deploy pilot chute is OK? First, some basic definitions. 1. Apex - The center of the fabric part of your pilot chute. 2. Skirt - Where the mesh and fabric meet. 3. Base - The center of the mesh part of your pilot chute. 4. Centerline - One or two pieces of tape, of fixed length, that lead from the apex to the base. 5. Bridle - A piece of tape, doubled in the case of a collapsable pilot chute, leading from the base to the deployment bag. 6. Kill line - A single piece of line, on a collapsable pilot chute only, that runs from the apex, through the center of the pilot chute, and down through the bridle to the pilot chute attachment point at the bag, or in some designs, to the apex of the canopy. 7. Support tape - 4 pieces of thin tape, sewn to the mesh, leading from the base to the skirt. 8. Bias - Simply put, the direction the mesh stretches the most (a diagonal line, at 45 degrees to the little squares that make up most mesh used in hand deploy pilot chutes). Sorry for all that defining, but if you don't understand those terms, you won't understand what comes next. OK, now the easy part. If you want your pilot chute to always function properly, simply make sure, in the inflated state, that no part of the skirt is above the apex. In other words, make sure neither your centerline nor your kill line is too short. I pulled the apex on my hand deployed pilot chute for two reasons. 1. It makes them open faster. 2. It yields 11% more drag. However, IF THE APEX IS PULLED DOWN BELOW ANY PART OF THE SKIRT, THE PILOT CHUTE WILL NOT FUNCTION PROPERLY. How do I check that? First cock you pilot chute like you would during packing. Now hold your pilot chute UPSIDE DOWN by the bridle at the base. Simultaneously pull downward on the apex (handle) and each support tape where it touches the skirt. The apex should be equal to, preferable slightly "below", but never "above" the skirt. (Please remember, the terms "above" and "below", in quotes, refer only to the "upside down" pilot chute you are holding in your hands for this test.) Now look how your support tapes are sewn to the mesh. If they are sewn "on the bias" your pilot chute is properly constructed. If they are not sewn on the bias it means that the mesh halfway between each support tape IS on the bias and will stretch more than enough to allow the skirt to get way "below" the apex. Try it. It's like a round parachute with several different line lengths. It simply doesn't work very well. This extremely common construction error might not let your pilot chute fully inflate, or in extreme cases, inflate at all. If your pilot chute is "borderline" when it is new, then things will get worse and worse as it ages. Now to "adjusting" a correctly manufactured pilot chute. Kill lines are usually made out of Spectra (Microline). Friction generated during the collapse sequence causes heat, and Spectra SHRINKS when heated. This means that your centerline could eventually get short enough to prevent your pilot chute from inflating correctly. Use what you have learned above to recognize this situation, and correct it. This is just a BASIC primer on pilot chute construction, and does not address several other important design considerations such as fabric and mesh choices, and how pilot chute size vs. the weight of your main canopy affects seperation velocity, snatch force, opening shock, and malfunction rate. More about these another time. Bill Booth

Pilotdave; What happened to you is getting more and more common. As a matter of fact, last Sunday, a jumper came up to me, said that he was having "pilot chute hesitations" on his Vector, and asked me to have a look. His problem, it turned out, was the same one I've seen countless times before...His pilot chute was made by "God knows who", and made incorrectly. It seems that dozens of people, who have little idea what they are doing, are making and selling hand deploy pilot chutes. I don't know about you, but one of the the scariest malfunctions I can think of, is a streamered main pilot chute that has enough drag to open your main container, but doesn't have enough drag to lift out the bag. What do you do? If you just lie there and wait, the ground may "rise up to smite thee". If you pull your reserve, your main is going to simultaneously deploy, and main /reserve entanglements are rarely much fun either. What to do...Easy, don't jump an incorrectly manufactured or adjusted pilot chute. So how can I tell if my hand deploy pilot chute is OK. First, some basic definitions. 1. Apex - The center of the fabric part of your pilot chute. 2. Skirt - Where the mesh and fabric meet. 3. Base - The center of the mesh part of your pilot chute. 4. Centerline - One or two pieces of tape, of fixed length, that lead from the apex to the base. 5. Bridle - A piece of tape, doubled in the case of a collapsable pilot chute, leading from the base to the deployment bag. 6. Kill line - A single piece of line, on a collapsable pilot chute only, that runs from the apex, through the center of the pilot chute, and down through the bridle to the pilot chute attachment point at the bag, or to the apex of the canopy. 7. Support tape - 4 pieces of thin tape, sewn to the mesh, leading from the base to the skirt. 8. Bias - Simply put, the direction the mesh stretches the most (a diagonal line, at 45 degrees to the little squares that make up most mesh used in hand deploy pilot chutes). Sorry for all that defining, but if you don't understand those terms, you won't understand what comes next. OK, now the easy part. If you want your pilot chute to always function properly, simply make sure, in the inflated state, that no part of the skirt is above the apex. How do I check that? First cock you pilot chute like you would during packing. Now hold your pilot chute upside down by the bridle at the base. Simultaneously pull downward on the apex (handle) and each support tape where it touches the skirt. The apex should be equal to, preferable slightly "below", but never "above" the skirt. (Please remember, the terms "above" and "below" refer only to the "upside down" pilot chute you are holding in your hands.) Now look how your support tapes are sewn to the mesh. If they are sewn "on the bias" your pilot chute is properly constructed. If they are not sewn on the bias it means that the mesh halfway between each support tape is on the bias and will stretch more than enough to allow the skirt to get way "below" the apex. Try it. This construction error might not let your pilot chute fully inflate, or in extreme cases, inflate at all. If your pilot chute is "borderline" when it is new, then things will get worse and worse as it ages.

I don't know about the other manufacturers, but Relative Workshop is already working on an aerodynamic, retractable landing gear pod, with a drogue for after touchdown deceleration, and a small reserve parachute, in case you get a bad spot and can't make the runway. I figure we can sell it for about the same price as a Vector, but the neat part is that we figure it will be pretty much destroyed after each use. So the customer will have to buy a new one for each jump. Wait a minute...if the pod is destroyed after each jump, the customer probably won't need a new one... Oops!... Never Mind.

Nathan; Generally, risers are easily interchangeable. Just make sure the whole system, once assembled, meets the requirements posted on the Relative Workshop website under "technical". However, if you add new risers that are more "bulky" because of the introduction of dive loops or short hard housings, tuck tab riser covers on certain rigs might not stay shut as well as they used to. Bill

Ramon; I assume you mean PdF's "Integrity", or backward facing risers, which have no grommet through the main body of the riser. Instead they have a small tab with a grommet on it for the locking loop to go through. (This type of riser came about because of the belief that the through grommet weakens the riser. This is not true, however. Risers actually break where they go around the harness ring.) Nonetheless, the ring alignment rules also apply for this type of riser. However, because the white locking loop does not double back on itself, forming a 2 to 1 pulley, these risers generally have only have half the mechanical advantage of properly made risers. I have tested several different incarnations of this design, and found that while some were better than others, none were as good as the "normal" 3-ring design. Another problem here is that I can't find any published design or performance specs for this type of riser to refer you to. So there is no way, other than dynamometer testing, for you to determine how good or bad your risers are. Sorry. Bill

"Cutaway forces have been very low on previous cutaways on this system." On the previous cutaways, were you spinning? A poorly designed 3-ring system might work fine on a 1 "G" malfunction, but yield a hard or impossible pull on a 3 to 5 "G" spinner. After you check out your risers at the Relative Workshop web page under "technical", let me know how far off they are. Your soft housings may also be a problem. They cannot stretch to meet riser stretch during a high "G" malfunction, and therefore put a lot of force directly on the white loop, instead of letting it be reduced by the rings. Without actually looking at your "breakaway rig", I can't offer any more guidance than that.

Gary; Call Relative Workshop at (386) 736-7589. Bill

Lummy; After landing, isn't it nice to know, every time, that your main protector flap was tightly shut during your entire jump, not flapping open, waiting for just the right wind angle to grab your pilot chute bridle, and pull out the curved pin. Especially if you were just head down doing 200 mph. It was specifically designed to stay shut all the way through deployment. This also gives your suspension lines a lot less to tangle with while they're "bouncing around" in the burble. Say thank you. Bill

Skydiverek; You're right. The smoother the surface of the hardware, the less friction. Since 3-rings do not depend primarily on friction, the smoother stainless steel surface lowers their "efficiency" by only about 5%. So this is not a factor in correctly made mini 3-rings. However, if other things are wrong with the construction of your 3-ring, it certainly doesn't help, does it. Electroless nickel plating is the least "slippery", with cadmium somewhere in between. Where slipperyness (is that a word?) does matter a great deal is in friction adapters, especially your leg strap adapters. Some early attempts to simply make copies of cadmium plated carbon steel adapters out of stainless resulted in adapters that slipped a lot, especially when the webbing gets old or dirty. We just replaced the stainless adapters on a rig made a couple of years ago with 500 jumps on it. They worked fine for a while, then started slipping as the webbing got older and dirtier. New stainless designs slip a lot less, but the jury is still out as to how well they will hold up at 1 or 2 thousand jumps, under all possible conditions. The dirt or sand at different drop zones seems to affect webbing differently. All I can say is, when you buy the latest and greatest, be prepared to be a "test jumper". It is impossible for the manufacturer to test a new product for thousands of jumps, under every possible set of conditions. I hate to say it, but that task, traditionally, has been up to the users. To my knowledge, slipping hardware has never endangered anyone life. It's more of a nuisance than anything else.

Lindsey; I'm glad I can still make someone's heart go pitter-pat. Thanks.

Dan; Measurements "A" and "B" are OK. It bothers me that your short (right) 3-ring housing will not stretch upward to accept opening shock a minimum of 1". That's how much the riser grommet moves upward as the risers stretch during a HARD opening shock. The dimensions you gave me for "B" lead me to believe that measurement "C" is not as bad as you say, unless you have "no stretch" 3-ring housings. Anyway, your risers are OK, and better than most I see. Last year I was at a gear show in Europe, and EVERY riser on EVERY new display rig was far worse than yours. Since the 3-ring release system is a child of mine, I hate to see it corrupted like that, especially because it costs no more to correctly manufacture 3-ring risers than it does to make them incorrectly. Bill Booth

Mike, Since there are about 10 million possible variations of length, color, ring size, ring material, webbing size, dive loops, toggle types, and RSL options, nobody in their right mind stocks risers...except by accident...That is when you make 'em wrong because of all the stinking options. I looked through the Relative Workshop's rather large box of mistakes today, but sorry, not one set like you describe is there. Bill Booth

Dave, The fact that you are asking the question, "Which brands are safer?, is a wonderful thing. I means that you understand that just because something is TSOed, doesn't mean that it is made to the highest standards. What equipment is best for you is a hard question to answer without knowing a lot more about you. First find someone who has been around for a while, and will not directly profit from selling you something that has been sitting on the shelf for three years. Then ask that person for his or her opinion. Making a careful, sensible choice when buying parachute gear is one of the most important things you will ever do in your life. There is a lot of good gear out there, but there are a few "stinkers".

Tom; I'm not sure I understand your question. If you have a complete "large" 3-ring setup on 1", type 17 risers, then the mechanical advantage of the system is the same as if you were using 1 3/4", type 8 risers. However, if you have a large ring on the harness only, and are using a normal mini 3-ring riser, then you have even less mechanical advantage than if you had a "small" ring on the harness. (ie. a normal mini 3-ring setup) The "fatter" cross section of a large harness ring lessens the lever arm" of the first riser ring, giving the whole system less mechanical advantage. The difference isn't drastic though, and if the riser is made correctly, everything should work just fine.

Paul; Precision makes a good product. Many thousands of people have used their reserves without incident. Mini 3-rings are NOT dangerous if correctly made. Almost everyone uses them, and people are not dropping like flies. My point here is to educate jumpers to the point where they know enough to demand the very best from the manufacturers. I'm sorry if I have unnecessarily scared you, and will be glad to talk to you personally about your specific gear. Call me at Relative Workshop after visiting www.relativeworkshop.com, and looking at the mini 3-ring photos in the "Technical" section. Bill Booth

CAUTION; Read this entire post before going to the pictures! I have posted, at WWW.Relativeworkshop.com, under "Technical" - " 3 ring risers", photographs of "correctly" made mini 3-ring risers. Our website uses "frames in frames", so you may have to use both right side up and down arrows to view all 4 pictures. Three ring systems that match these pictures can be expected to release even a 6 "G" spinning malfunction with relative ease. The pictured riser was manufactured to my August, 1998 specifications. Mini risers manufactured before that date may differ somewhat, even those manufactured by the Relative Workshop. This DOES NOT mean that your risers are necessarily dangerous if they do not match these pictures exactly. It does mean that the closer your risers are to these pictures, the easier it will be for you to release a high "G", spinning malfunction. This specification change was made necessary by the advent of super high performance elliptical canopies, which generated super high performance malfunctions. If you jump more conventional canopies, risers made to these "new" specifications may not be necessary. These specs were immediately made available to all parachute manufacturers, worldwide. Complete construction plans are available from the Relative Workshop. Here's what to look for: Picture "A". The greater the gap (arrow) between the top of the harness ring and the bottom of the loop of tape which holds the smallest riser ring, the greater the pull force required to release the riser at high "G's". Picture "B". The shorter the white closing loop (arrow), the greater the chance of damaging your yellow breakaway cable during a hard opening shock, and the higher the release force under high "G's". Picture "C". If your short (right hand) breakaway housing won't stretch "upward" to accept riser stretch during a hard opening shock, you might damage or even "suck through" the yellow breakaway cable, making a cutaway hard or impossible. In addition to these parameters, I highly advise anyone jumping a highly loaded elliptical main to add short hard housings to your riser channels, to prevent the free ends of the yellow breakaway cable from being "grabbed" by severe risers twists. If you want to jump super high performance canopies, you need super high performance risers. You should also clean and lubricate your breakaway cables every month. WARNING: This is only a guide. Not every parameter which makes your 3 ring release as good as possible has been included.

Amir; First, mini 3-rings are safe, IF they are correctly made. Secondly, the TSO is just a MINIMUM performance standard. Some versions of the TSO include no standards, or even the requirement, for a main canopy release of any description. In the years since the mini 3-ring was introduced, new canopies and new suspension line have upped the standard to which mini ring risers must be built, and some manufacturers simply have not kept up. A mini 3-ring riser made to a perfectly acceptable standard 5 years ago, might not work too well when you have a 6 "G" spinner on your new "Starfire 77". Try getting hot new computer software to work on a 5 year old computer. As annoying as a "crash" is on your computer, it's a lot more annoying when you're skydiving. Bill Booth

John; Properly made mini 3-rings, with hard housings, both on the rig, and on the risers WILL give you an easy cutaway up to 6 "G's", even with spun-up risers. I am in the process of building, and testing a bunch of mini-risers with common construction errors. This will enable people to determine exactly how bad, or good, a particular set of risers might be. Even though the study is not yet complete, I will post a few pictures of correctly made mini risers for you at Relative Workshop's website by tomorrow. The further your risers differ from these pictures, the worse they will perform. If you still have doubts after viewing the pictures, give me a call at Relative Workshop. Most mini 3-ring risers I've seen can handle a 1 "G" malfunction. The problems start happening when a highly loaded elliptical produces a badly spinning malfunction, producing 3 or more "G's". Some companies do a good job at making risers, some don't. And because risers tend to travel with canopies, you may or may not have risers made by the same company that made your rig. Bill Booth

Zennie; If your rig doesn't have hip rings, we, or any master rigger, could shorten your main lift web in a couple of hours, for not too many bucks. If it does have hip rings, it needs a whole new harness, which takes a while and costs a lot. Of course, if you had bought it from us, we would do the work for free. We do offer a satisfaction guaranteed warranty. As suggested above, simply tightening the chest strap does effectively shorten the main lift webs. If your chest strap doesn't keep hitting you on the chin on opening, you're home free. Shortening your leg pads can also help. If you jumped in Deland, you'd have 6 or 7 master riggers fighting over the job.

Zennie; We have been offering "tuck tab" BOC handles for quite a while now. Since I don't do a lot of free flying, I have no opinion on whether that style of handle is safer than any other. However, I do listen to the local free flyers, and several of them really like it. Bill

I REALLY LIKE IT! Signed - Bill Booth

If I've learned one thing in my 35 years in the sport, it's that it is very difficult to get most skydivers interested in safety. Years ago, when it became obvious that my hand deploy pilot chute and 3-ring release made it possible to deploy a malfunction, and then breakaway from it, 500 feet faster than the existing internal pilot chutes and Capewell canopy releases allowed, a lot of jumpers simply started deploying their mains 500 feet lower. Utterly negating the increase in safety these systems offered. Even today, most jumpers think that because all gear has a TSO tag on it, one piece of gear is as safe as another. Unfortunately, that is not true, and most jumpers will choose "fashion" over safety every time. Here are just a few examples of what I mean, starting in the '60's, right up to the present day. (1.) The army found out that if you put 2 foot band of fine netting around the skirt of a round parachute, you eliminate the most common deployment malfunction, the partial inversion. The trick worked so well that airborne troop static line malfunctions went from 1 in 250 to 1 in 250,000. WOW! So, a company that made round sport reserves (there were no square reserves yet) came out with an "anti-inversion netted" reserve. NO ONE bought it. You know why, of course...It packed up 10% bigger. Jumpers past up a proven 1,000 times increase in safety for smaller pack volume. (2.) Believe it or not, there is a similar, thought not nearly as drastic, choice jumpers are making when they buy a square reserve today. Let me explain. The first square canopies came without sliders, so they had to be built tough. This meant, among other things, that there was tape running spanwise (from right to left) between the line attachment points. With the advent of the slider and softer opening canopies, some companies began leaving the spanwise reinforcing tapes out of their square reserves. Why? Because they cost less to build, and (you guessed it) they packed smaller. This proved to be a wise choice, (at least in the marketing department) because although jumpers very often choose their mains for performance and durability, the almost always always choose their reserves base only on price and pack volume. While reserves without spandwise tapes are fine in most situations, as we have seen recently, they tend to fall apart when skydivers push the envelope. (ie. big people on tiny canopies, going head down at high altitudes.) Safety doesn't seem to be any larger a consideration than it was when they passed up anti-inversion netted round reserves in the '60's. (3.) Standard size (large) 3-ring release systems have never given a solo jumper any problem. They ALWAYS release easily and NEVER break. However, mini 3-rings look neater, so that's all people will buy. No matter all the reports of hard or impossible breakaways or broken risers. Don't get me wrong, Properly made, and maintained, mini 3-ring release systems will handle anything even the newest ZP canopy with microlines can dish out. Unfortunately, because they are now being pushed right to their design limit, they must be made EXACTLY right. And a lot of manufacturers either can't or won't. On the other hand, a large 3-ring system has so much mechanical advantage, that even a poorly made system will still work just fine. But then fashion is much more important than safety, isn't it? (4.) Spectra (or micro-line) is strong and tiny, so it reduces both pack volume and drag , which means you get a smaller rig and a faster canopy. Unfortunately, It has a couple of "design characteristics" (this is manufacturer talk for "problems") It is very slippery (less friction to slow the slider), and stretches less than stainless steel. This is why it hurt people and broke so many mini risers when it was first introduced. Now, I must say that the canopy manufacturers did a wonderful job handling these "characteristics" by designing new canopies that opened much slower than their predecessors. However, the fact still remains, that if you do have a rare fast opening on a microlined canopy, Spectra (or Vectran) will transmit that force to you (and your rig) much, much faster, resulting in an opening shock up to 300% higher than if you have Dacron lines. (It's sort of like doing a bungee jump with a stainless steel cable. At the bottom of your fall, your body applies the same force to the steel cable as it would to a rubber bungee cord, but because steel doesn't stretch, your legs tears off.) So why would I have a fast opening? Well for one thing, you, or your packer might forget to "uncollapse" your collapsible slider. BAM! Or perhaps you're zipping along head down at 160 mph with a rig that wasn't designed for it, and you experience an accidental container opening. BAM again. The point is this: If you want to push the envelope, and get all the enjoyment this sport has to offer, and do it "safely", you need to make careful choices in the gear you jump. If you weigh 200 lbs. and do a lot of head down, perhaps you really shouldn't be using a reserve without spanwise reinforcement, mini 3-rings, or a canopy with micro lines. No matter how much you weigh, you should educate yourself about gear, and then only jump gear that is designed for how you jump. So many fatalities occur because of decisions jumpers make BEFORE even getting in the airplane. Don't join that group. Be smarter than that. Fashion, at least in skydiving, can get you killed. Bill Booth

When asked, "all else being equal, would rubber bands on a freebag slow the reserve opening, compared to a line stow pouch?"...The answer, at least on a low speed opening (such as after a breakaway), is yes. If you ever need to open your main on the ground, pull your bag across the floor slowly and see how each rubber band stow "grabs" the lines as they unstow, and therefore "slows" the bags progress. The pouch on a freebag lets the lines out "easier". Also notice that the rubber bands grab the "outside" lines in each stow group, but not the "inside" lines, causing the "inside" lines to leave the stow first. This rather uneven release pattern looks a lot more "messy" on high speed films of deployments than the lines coming out of a free stow pouch do. Ram air canopies don't malfunction, their lines do. Therefore, it would follow that the "cleaner" the lines deploy, the better the chance of a good opening.

I think the main reason most us manufacturers use the free bag system for reserve deployment is inertia. ParaFlite tested and introduced the first square reserve, the Safety Flyer, with it. It worked well, and nobody (except Jump Shack) has seen much reason to change. I also believe that there is less chance of a bag lock with the system. Why not use it as a main bag system? Some people did at first, but the following problems soon became evident. 1. It takes longer to pack. 2. The Velcro, which holds the line stow pouch shut, wears out quickly, is a pain to replace, and over time, would cause suspension line wear. Let me clear up one myth right now. The free bag system WILL NOT pull your reserve bag out of its container in the event of a horse shoe malfunction. A horse shoed 16 foot long, 2 inch wide, free bag bridle generates only about 2 pounds of force on the bag at terminal velocity. Most reserve canopies weigh over 5 pounds, not counting force required to extract them from the reserve container, especially if the main container is still closed. What the long wide bridle will do, however, is stabilize the bag, (if you reach back and throw it out of the container) so that it won't tumble through its own lines as it deploys. So, if you ever experience a horseshoe malfunction of your reserve, don't just lie there and wait to hit the ground, sit up until you feel the reserve bridle hit you in the back of the head, reach back and pull on it until the free bag is out of the container, and then let go. The drag of the bag itself, helped out by the bridle, will then carry it to line stretch. I put out a film about this about 15 years ago, but a lot of people seem to have forgotten.

I tried Cordura pouches with elastic mouths 20 years ago, but had a lot of complaints about hard pulls. Going to Spandex pouches solved that problem. It was a godsend to manufacturers, because we have to put a pouch on a rig that will safely allow the use of ANY size pilot chute, made out of any material, from a 36 inch F-111 to a very slippery 18" ZP. It must be easy for the smallest girl to extract, but stay in the pouch during a 300 mph head down dive. Nothing I've tried can do all that but Spandex. But, as has been noted, Spandex is easy to damage, especially on tandem rigs. Boy was I glad when DuPont combined Spandex with Cordura to make Spandura. It has the stretch of Spandex and the toughness of Cordura. It comes in dozens of styles, so it took a lot of experimentation to find the right one, but it sure paid off. We have been using it on Sigma Tandem systems for about a year now, and are very happy with the results. It will become "standard" on all Vectors this month. Who says you can't have your cake and eat it too. I'm sure other manufacturers will eventually "discover" it too, and it will become the industry standard. Bill Booth