polarbear

Ideally, the lines don't unstow from a freebag pouch all at once. They should be carefully s-folded into the pouch such that they unstow in a smooth, controlled fashion, one layer of the s-fold at a time. It isn't too difficult to pack the reserve in this manner, but in my experience it takes a bit more time and patience then using the rubber bands on a main bag.

Interesting...I guess I believed the propaganda that the wider reserve bridle might provide enough drag to deploy a horseshoed reserve. Thank you, that is worth knowing.

In reply to: Given that, being able to accurately compare canopy sizes is important. I've already heard of two examples of people going from a Sabre 150 type canopy to a Safire 149, thinking that the only thing that will change is the higher landing performance from the elliptical shape. Instead, they found out they had also gone one size smaller. This is exactly what I am asking about. About a year and a half ago, I was jumping a sabre 170 and was interested in trying out a Safire. Icarus suggested a 189 based on the fact that PD canopies measure large by PIA standads. I understand/agree that the only way to really be sure is to try the canopies before buying...always the best advice. I am just curious if in general people find that PD canopies (which measure larger when measured by PIA standards) fly big compared to other brands which are measured by PIA standards.

I've always thought of it as fewer line stows=less chance of a baglock. Having only two line stows in the center of the bag (as opposed to the outside of the bag, where most main bags have stows) translates to greater chance of an on-heading (or un-twisted) opening. Also, reserves are designed so that they have a chance to open in a horseshoe condition. This is why the reserve bridle is so wide and may have some sort of assist device like nylon pockets sewn on it. The idea is that if the reserve PC gets caught/tangled on some part of the jumper, the bridle is supposed to supply enough drag to unstow the lines and alow the reserve to deploy. It takes more force (in my opinion) to strip lines from a line stow rather than a pouch, meaning that the bridle may have an "easier" time getting the reserve out. Stowing lines in a pouch takes a bit more finese/time to keep them organized. I would also expect that lines in a pouch *may* be more susceptible to line dump. This is all speculation on my part...I don't really know for sure.

It's come up in some other threads about the differences in canopy pack volume and area that arise from measuring the canopies differently. Different manufacturers use different measuring techniques; thus when an attempt is made to standardize the techniques (ie the PIA chart), some different numbers come up. I started thinking about this more in depth because I am preparing to change main canopies. My question is this: What are people's experience with canopies of the same advertised area from differnent manufacturers? Canopies are sometimes referred to as "flying big" or "flying small", does this come from the differences in measuring area? I am specifically interested in switching from a PISA canopy to a PD canopy. By the PIA method, PD canopies measure bigger in area than what PD advertises. Do people find that PD canopies "fly big"?

I have also heard people say that a Cypres makes needing an RSL uneccessary. That is really a pet peeve for me...the two are NOT substitutes for each other; they are designed for different circumstances. It is also true that having an RSL deploy the reserve is much cheaper than having a Cypres deploy it. Hey, whatever gets the nylon over your head. Just make sure its there! (and square, and flyable...)

People do jump Stilettos at higher (above 1.8) wingloadings. PD claims that if you want to jump at higher than 1.7, either a vengeance (up to 1.8) or a velocity will give you "better" performance. The newer high-performance mains (cross-braced mains, cobalt, etc.) are really designed for the wingloadings you are talking about. Jump what YOU like best.

I am really surprised that more people haven't argued against using an RSL; most of the jumpers I know don't use them. I think RSLs are a good thing. If you look at the accident reports, you will find incidents that were made worse by an RSL. But, there are more that happen because someone cut away low and didn't get a rserve out, or because someone cutaway and didn't pull the reserve, or becasue someone couldn't find/pull the ripcord handle... There are reasons for using one or not using one. You have to take the time to hear both sides of the argument and apply it to your personal situation. In this sport, knowledge is the first step to survival!

Silicone...Do this once a month. Remove the cutaway handle. Wipe the cables clean with a cloth that has been sprayed with silicone. Do not leave excess silicone on the cables; it will atract dirt. While the cutaway is removed, take apart the 3-ring assembley and flex the end of the riser (where the 2nd largest ring is attached). Also flex the loop that holds the small ring and the loop that holds the cutaway cable. Check your container owners manual for procedures and/or get a rigger to help out. The above maintenence should be performed (and we all actually do it, right?) once a month. The cutaway cables can dirty and the riser ends will get stiff and aqcuire a "set"; by cleaning and flexing everything you can reduce the likelihood of a hesitation on cutaway.

Frankly, I think it is your rigger that is misinformed. It seems to me that he/she is the only one who believes that the elastic keeper should be down at the friction adapter. I would suggest you talk to the manufacturer of your container and see what they have to say.

My experience has been that the used gear market is pretty strong. I have had good luck with it. My recommendation is to start with used gear...it's cheaper (generally) and it is very likely you will want to downsize in the somewhat-near future. In addition, after you have accumulated a few hundred jumps, you will have a much better idea of exactly what type of gear you want (do you want stainless hardware? Rings on your harness? Collapsible PC? Spectra or Dacron Suspension lines? Soft or hard reserve ripcord handle?) so you will be less likely to plunk down hard earned cash on equipment you won't want after a short period. Your 3rd option also seems reasonable...just keep in mind that you can only safely downsize 1 or *maybe* 2 sizes with a given container. Whichever route, you should be able to get quality equipment for a reasonable price. Get the riggers and instructuors you jump with to help you make a decision.

Now that you mention it, I think you're right. I was just remembering what I read in the Parachute Manual about ZP-coating contributing to lower tear strength. I do seem to recall seeing that the specs on Soar-Coat dictate a higher tear strength. I suppose there are other factors than just the coating. billvon is right; the MZ reserves are only zp-topskin.

I have heard people say in the past that zp will continue to tear under a lower force than F-111. Both fabrics are ripstop, but the coating process on the zp fabric "traps" the fibers in place, so when a tear starts, the fibers can't redistribute themselves as easily to resist the tear. In F-111, the fibers can move a little to resist the tear more. I have seen several zp canopies with small holes in them that have not propagated or gotten larger with use. I don't usually consider the lower tear strength as a serious detractor of zp material.

I don't doubt that. But, you have to consider that Triathlons and Sabres come from different manufacturers and are made of different materials. The area of the canopies may even be measured differently, meaning that maybe one of the 135's isn't really 135 square ft. In the examples I mentioned earlier, we are comparing canopies made by the same manufacturer, using the same materials, using the same construction methods, and measured using the same techniques. I personally have packed both a spectre 170 and a sabre 170 into my container; I know from experienece that the sabre packs larger. It still remains to be explained how (according to the PIA chart) the sabre packs smaller in the 170 size, but the spectre packs smaller in the 190 size. I still say, read the article on PD's website and use the PIA chart with a grain of salt.

Vol I doesn't really discuss much "modern" gear, but it should be pointed out that even Vol II. was written before a lot of the gear you see in skydiving today was brought out. It does, however, discuss the ram-air parachute and piggyback-style container systems, which is what we use today. I would agree that Vol I. contains more of the basic information for maintenence/repair/etc. As far as aerodynamics goes, neither manual is really thorough. I guess it depends on the level of aerodynamics you want. If you just want the basics, it will be in the parachute manual. If you want a more detailed description of what happens when you pull a toggle, what happens when you pull a riser, etc, check out the on-line resource mentioned above...it's pretty good. If you are thinking of becoming a rigger, you will eventually want/need both Volumes. Most riggers/DZs will have copys of the manual. Check 'em out and see if they have the kind of information you want.

The technology may be at hand, but I'm not sure we could just grab it "off the shelf". I would guess that new materials would need to be developed, or at least refined, and the design and TSO processes would take some time.

Its basically exactly the same as the difference between packing an F-111 main vs. a ZP main. The biggest difference, as I see it, is that when packing a reserve, you are much more careful to make sure things stay in place (especially the lines). The slippery ZP might lend itself to having things slip out of place during packing, as well as the usuall difficulties of getting the air out of the canopy and getting the canopy into the bag.

Me personally, I go with the carve. I do agree that it is "harder" to get good accuracy and is "harder" to perform it at the right altitude, but I think that aerodynamically, a carving maneuver puts the canopy in a better position to build up speed. One thing I have noticed is that on my canopy, if I time the carve such that I come out of the carve at the right altitude so I don't have to double-front the rest of the way down, I get more speed than if I come out high and have to double-front to get lower. One observation I have is that a canopy with a large/negative recovery arc will do better with a snap turn...since it will not recover as fast, it is in the "dive" configuration longer and has time to build up speed. A canopy with a short recovery arc (A lightly-loaded stiletto?) will not stay in the dive very long, and thus will not build up as much speed. During a snap turn, the quick-recovery canopy (I think) gets most of the benefit from the pendulum effect of the pilot. Thus, I think that a quick-recovery canopy will do better with a carve. A second observation is that good swoops seem to depend mostly on how smoothly the entire landing maneuver is executed. Whether it is a snap or a slow turn, I think the ability of the pilot to perform the maneuver in a smooth manner is crucial. Thus, I would expect that a pilot who had better technique with a snap hook to get better swoops than he would from a carve. I'm not a very experienced jumper; my observations come mostly from watching the experts, my understanding of aerodynamics, and maybe 150 agressive landings.

F-111 is supposed to be 0-3 cfm porosity, which is "almost" like zp. The problem is the fabric opens up after a few jumps, which increases porosity. ZP doesn't do this. However, as reserves are usually not used often, the porosity issue doesn't show up much. Most reserves have a lifespan-PD reserves are good for 25 jumps or 40 repacks, then they must be porosity tested at the factory. Tempo reserves (I think) are good for only 5 jumps. I don't know about Precision reserves. ZP is harder to pack...I have met some riggers who will not pack a zp reserve. A jumper at my DZ looked into getting a Raven MZ, but was told that it would not fly/flare any better...the only benefit is that it lasts longer. Personally, I stick with F-111 reserves strictly for the easier packing.

Bill, one question I have to ask is that is there any consideration as to actual altitude loss during the 3 seconds required by the TSO? To me, altitude loss is the real consideration. It seems as if a subterminal opening might eat up less altitude per time unit, thus meaning that it would be OK to let a sub-terminal opening take a little longer. Might it be reasonable to redefine the TSO in terms of altitude loss? I imagine it would be hard to certify that a canopy used up a predictable amount of altitude during opening at a given speed. One thing I have to say is that I'm not sure that an idea you discussed in an earlier post is such a good idea. You mentioned a sort of "high-speed" reserve, meaning one that was designed to open acceptably at high speeds, but would fit in its own TSO class and thus would not need to obey the 3-second rule. I guess I think that while some high-speed deployment accidents would be prevented with a "high-speed" reserve, there would be at least as many that came about from the "high-speed" reserves not opening in time in a sub-terminal situation. I think there could be some real potential in using energy absorption methods, like materials that are designed to stretch or break at higher forces and thus eat up some of the high-speed deployment energy.

I am also by no mean an expert, but I can throw in $.02 here: While it is true that the slider sees less air pressure holding it up during a subterminal opening, it can still develop a large amount of force. Try driving down the road at 30 mph holding a slider open. Then try driving down the road at 60 mph holding the slider open, and you will see what I mean. Also, during a subterminal deployment, the canopy itself will see less air pressure trying to spread it open and push the slider down, meaning that the forces trying to push the slider down are less. I think it is true that many years of experience tell us that subterminal openings are often (usually?) slower/softer than terminal ones.

For the most part, this is true. The chart does have some discrepancies...the chart I have seen (which is in the back of the para-gear catalog) says that a sabre 170 packs smaller than a spectre 170, even though the spectre has two fewer cells and line groups with asociated seams. Move further down the chart, and it says that a spectre 190 packs smaller than a ssabre 190. How does the spectre pack smaller in the 190 size, and the sabre pack smaller in the 170 size? Another example that PD cites in their article is that the chart shows a PD 235 7-cell has a larger pack volume than a PD 260 nine cell. Both canopies are F-111, with simillar construction and airfoil profiles, and the seven cell has 25 ft2 less area, two fewer cells, and two fewer line groups. How can it pack larger? I could list other examples, but I am sure this is already getting boring. I don't mean to say that the PIA chart is useless, just that I think it is more appropriately used as a guideline, nothing more. In my limited experience, the container manufacturers seem to be able to give good advide as to what fits and what doesn't in their containers.

The pack volume chart is useful, but I think it should be pointed out that it is only a guideline. The different pack volumes can be measured by different people under different conditions, giving different results. PD has a great article on pack volume on their website...I suggest anyone using the PIA chart go and read the article.

Interesting notion...yet another variable in the equation of what gear to buy! I suppose something like this could have its nitch.

Hey Clay, Glad you like the new canopy so much...the ellipticals can be a lot of fun! They also can seem "easier" to land...you have a more efficient wing, and thus have more ability to fly your way out of trouble if something isn't quite right. It does, of course, require that you recognize the problems and respond correctly to them. Keep in mind that many people don't get hurt on the first few jumps on a new canopy. Its when you find yourself in an undesirable/unfamiliar situation...landing in a bad spot, landing at high altitude, getting surprised by the altitude loss during a hook turn, etc. that the higher performance wings can REALLY get tricky. Remain vigilant, treat it with respect, and have fun!