alan

A pop top that is that loose is not safe to jump in my opinion. There are quite a few rigs out there that don't have issues associated with an exposed reserve pc top. You can find good bargains on them as well. Why mess with an exposed reserve pc top when you don't have to? Because they deploy quicker? Ya, right. I'd like to see any real evidence of that. alan

No rig is tamper proof. I can take a razor blade and cut the seal and thread, open the reserve, do whatever I want and pinch it closed. You'd have to be looking for it to know that I did it and even then it would not be all that easy unless you knew what to look for. alan

A flat turn is initiated by smoothly applying downward pressure on one toggle. As the turn commences, you apply slightly less pressure to the opposite toggle, just enough to maintain altitude AND airspeed. Slight adjustments with either toggle can be used to control the radius and rate of the turn. If both toggles are eased back to neutral in a coordinated manner, the turn can be executed with very little loss of altitude and will recover at about the same airspeed as when the turn was initiated. It takes lots of practice and really has nothing to do with 1/4 brakes or 1/2 brakes, it is about applying pressure and feeling/seeing/hearing how the canopy is responding and then making smooth adjustments. Going to brakes and then letting one up a little is a braked turn, not a flat turn. The difference is subtle but important in terms of lost airspeed and altitude. If you find yourself too low to complete the turn you can finish it in a flare, which you want to have conserved as much airspeed as possible for. You flare with both toggles from the flat turn positions but slightly faster with the outboard toggle to "catch up" with the inboard toggle. The real trick is to be very smooth and be ahead of the canopy. You have to fly it and not respond to it. Make it do what you want it to. Practice this a lot up high, every jump if you can safely. Most important is to land with your wings level and keep them that way. Do a search of my posts in the Incidents forum......there is a very recent one that I quoted a very nice posting to the rec.skydiving ng from Skratch Garrison. You must read it. If you can't find it, e-mail me and I'll forward a copy. alan

Man, I've explained this one sooooo often. Have someone video your opening and watch the time on the camera. Do you chuck at 3200' or is that what you perceivce your altimweter reading to be at the time you decide to chuck? How do you define a snivel? Chuck until slider down or canopy out of bag and slider down? How about slider 3/4 down, which is generally taught as a good canopy? Do you realize you are moving at 176'/sec while you look at the alti? Do you know that there is a lag of a hundred or twohundred feet on your alti in freefall?I've seen/video'd a few tandem *openings* that have taken a thousand feet, but they have been pretty rare in my experience. I have yet to see anyone verify 1000' "snivels every time" on video, but then I've only been doing this for over ten years and have only been on a few thousand jumps, more than just a few on several different Crossfires. See if this scenario fits. Assume you have the pc in your hand and are "waiting" for 3200' Look at alti and "see" 3200' (after you have tracked and waved off) Possible parallax error, lose 50' to 100' Brain processes image, lose another 50' Lag in altimeter catching up with descent, lose 100'to 200' Actually decide to release the pc, lose 50' Line stretch and canopy out of bag, lose 100' Actual "snivel" portion of deployment, lose 500' Get "squared away" and check alti, lose 50' Using the conservative side of the numbers that gets you "in the saddle" at about 2300'. Maybe you get a 600' snivel and your alti lags 200'. At any rate, you are sure going to "see" something that looks a lot like a 1000' snivel, especially if you are a newer jumper, although I see some very experienced people do the same thing. Hell, maybe you pitch at 3200' and are in the saddle at 2000'. You may have travelled 1200' during your opening, but the actual snivel would still only be around 800'. I'll bet you've guessed by now that this 1000' "snivel" thing is a pet peeve of mine.

Ummm, corect me if I'm wrong, but even when you induce the extra speed and lift, doesn't the canopy still have to slow down and cross the same speed/lift threshold that you have on a normal straight in approach with no extra or induced speed/lift? Wouldn't that mean that from that point on they would fly and land the same? So, wouldn't the extra speed just lenghten the surf *before* that threshold and have no real effect on the performance after it? Double fronts can teach you to surf longer and ease you in to faster, higher performance landings, but they don't teach you how to finish your landing. Learning the low speed performance characteristics of your canopy does that. You can/should do that up high. I guess, indirectly, the longer surf closer to the ground does contribute to learning slow flight, but it is a myth that induced speed will allow you to land better on a canopy that you *can't* land straight in. alan

You were lucky. I think much better advice would have been to make a few jumps on at least one canopy size in between. All is well that ends well and your Tri is a good choice. I am sure it will treat you well for many, many jumps to come and give you the opportunity to learn more about being a good canopy pilot......if you make the effort and take the time and jumps to learn. There are many good articles with advice in them, many right here in this web-site, just do a little searching. PD's web-site also has some great stuff as well as Icarus. Try this article, it is a little on the technical side, but if you gloss over the numbers and formulas, the basics are there. http://www.afn.org/skydive/sta/highperf.pdf alan

Hook, I've watched video of quite a few tandem drogues and they seem to really wander around a lot, maybe even enough to make it more work for the TM to keep the ride nice and smooth. Ever wonder why they don't put a vent at the apex to reduce the oscillations? alan

When the conventional canopy breaths, that implies that it "exhales". During the exhale, the canopy is less pressurized and therefore more distorted and less efficient, providing less lift. In addition to that, during the exhale the canopy "accordians" in, giving it less wing span (effectively giving you less wing area) and also adding more curveature to the top skins between the ribs, which increases the vectored lift component and decreases the vertical lift component. What this means is that you have it backwards. The conventional canopy will be less efficient in turbulence and be more likely to drop you a few feet more than the airlocked canopy. alan

Dan, you also used to claim (and still do) that your non-cross braced canopy (Cobalt) was (is) the superior choice to over the popular cross braced canopies. Yet, cross bracing seems to found its way into your line of canopies, such as the competition cobalt with the cross braced nose....where it really counts. Your Onyx also utilizes cross bracing. alan

This was preceded by: Along with a few other observations that should have made it obvious that the question was rhetorical in nature. I was around when motorcycle helmets were used by skydivers. Want to have some fun? Get a 12 oz boxing glove, then let a trusted friend clobber you on the back of the head. Then put on your $300 high tech composite helmet and ask them to clobber you again with as close to the same force as they can. I know, it is not very scientific and very subjective, but it will be funny as hell. And, just for kicks, if you have a full face helmet, let them lay a shot right on the chin part of the helmet. If you are not in the emergency room yet, try to get a set of the foam rubber protective head gear used for sparring and take the same shots. That may give you some idea how effective the hard shell is at distributing the load over a larger area. There is nothing wrong with always wearing a helmet if you so choose, but if you go that route, then wouldn't it make sense to ensure that the helmet you are wearing is actually the best one for the job? alan

You have misunderstood. The reason we do a speed building turn has nothing to do with the flare or shutting down. The turn and resulting speed only serve to increase the surf. How much the surf is increased greatly depends on how efficiently the pilot flies the canopy. The point is, that whether the canopy is doing 70, 60, 50, 40 or 30 on approach, at some point all of them slow past the 30 threshold which is close to what the majority of sport mains in use today do on a straight in approach. Once they reach that point, they fly flare and land the same for a given canopy. You don't shut the canopy down at 60, you surf it and bleed off the excess speed. Deuce's problem doesn't lie with the initial speed, it is with his flare technique and how to fly at the low end. I usually advise people with new canopies or little experience to make a few high hop and pops and do a lot of flying in brakes and flaring to learn the slow flight characteristcs of their canopy. I can do a 360 degree front riser turn onto final under my 89 X-Mod VX (at about 2.45#/ft2) and be doing close to 80 mph at the bottom of the recovery arc and after over 200' of surf it slows down to under 30, where I start shutting it down. On a hot light or no wind day, I can slide or run it out in 5 or 6 steps. I can fly the same canopy doing a straight in approach where it normally is going about 40 or 45 in full flight and use the same technique, except now the surf is only 50 or 60 feet but the canopy slows to under 30 and I shut it down just the same. I don't think Deuce ever stated he didn't want or had a problem the extra initial speed, he just said he has a problem running out the landings and he'll always have that problem until he learns the slow speed flight. Anyone having trouble shutting down their canopy should take a second look at the trim and brake setings, perhaps re-evalute their piloting skills and wing loading, or maybe get some video and coaching. You should not need to do a speed building manuever in order to get a good landing. If you can't get a good landing, with a decent little surf, on a straight in approach, then you really should not be doing anything approaching a high performance landing. So, while Deuce perhaps shouldn't be doing the turn, simply stopping it will make him a little safer, it won't improve his landings until he learns how to fly the canopy at the low end of its' speed range. I hope this makes a little more sense to you. alan

A cracked shell in and of itself is not necessarily a sign of a superior helmet, neither is one that doesn't crack. The foam liner and fit interact with the shell to provide varying levels of protection. A Protec for example may not crack or split because of the soft shell, but it flexes to absorb energy. Combine that with a good fit and thick foam padding, you have a helmet that offers a high level of protection. The weight of the helmet is also a factor. A heavy helmet can cause neck injuries because of the kinetic energy they generate. It seems that protection is a series of trade offs and that a helmet that is a good choice for one application may not necessarily be good for another. I have to wonder why skydivers don't use premium motorcylce helmets or auto racing helmets? I would also wonder what is more effetive, spreading the force of impact over a larger area (in this case most of the skull, which is a somewhat limited area) or absorbing the enegry before it is transmitted to the skull. alan

Building up speed will give you a longer surf, how much longer depends on how efficiently you fly the canopy. But, as you surf, the speed bleeds of until you reach a threshold the same as if you had done a straight in approach, so the flare is not really changed by the added speed.....just the surf. Well, unless you flare to early while you still have too much speed, then you will find yourself popping up. The trick to a Safire is to be patient, it will surf longer than most people realize, so don't put your feet down too early. Then finish the flare with a deep stroke, deeper than you would expect, especially if you have been accustomed to PD canopies such as the Sabre. alan

That is a myth. You can do a straight in approach at 30 mph or front riser carve at 60 mph, but either way the canopy still crosses a speed threshhold when slowing down. The canopy doing 60 still slows down to 30 during the approach and from that point on flies just like the canopy that did a straight in at 30. alan

Many knowledgeable people posting here will tell you that a helmet shell that cracks has absorbed much of the impact energy that would have been tranferred to your head, skull and brain, while one that doesn't, such as carbon fibre composites, tranfer much of that energy to your skull and can result in more serious injury to the brain. A lot of the newer jumpers like to advocate always wearing a helmet because of the added safety and protection, yet when you see what they are wearing it becomes obvious they are only concerned with the added protection as long as it looks cool. They would prefer to wear a more expensive helmet that looks neat rather than a less expensive model that offers more protection. alan

I think they are. You do realize that AFF is not the only learning method? I believe that under the new ISP, which integrates SL, IAD, AFF and AFP, that flat turns are a required part of the canopy instruction. alan

My post wasn't intended to endorse jumping either with or without a helmet, it was intended to provide some information that could be useful in making an informed decision (we should at least acknowledge the cons) and to try to get a few of us to look at what really happened in this incident. The issue of the premature opening, I think, is far more critical than the decision to wear protective head gear. The focus of this thread seemed to jump right to a rash of endorsements for helmets because of one comment and no one questioned the root cause of the accident or what may have been done to prevent it. I find that disheartening. There is an old saying, "An ounce of prvention is worth a pound of cure.", that was kinda my point and maybe it was a little foolish of me to try to point out that there even are any risks associated with something we all already know does more good than harm. My bad for even considering both sides of an issue. alan

Pasha, canopies are inflated because they are pressurized from air ramming into the nose air inlets. More speed increases the pressure until an equilibrium is reached and a stagnation point forms outside the nose. If you radically change the attitude of the wing, the stagnation point will move up or down and create a venturi effect that will suck air out of the parachute, thereby reducing the pressurization. Flying slower will also reduce pressurization. Anything that will reduce pressurization in your canopy has the potential to cause it to collapse. Turbulence can do this. Flying in brakes can do this. Here is a link to a very good article that covers this topic and much more, it may be too technical but if you skip the number crunching and follow the text, it will give you some valuable insights as to how and why are parachutes fly. I hope this helps and isn't too confusing. http://www.afn.org/skydive/sta/highperf.pdf alan

It's graet to give recognition to people/businesses that have treated you well but if we all did this, the Gear and Rigging Forum will get cluttered with atta boys and people with real questions/issues will get lost in the clutter. I would suggest that the Talk Back Forum is a more suitable site for this type of post.....although, finding good gear and dealers is an issue. Tough call for me. Folks, just use your best judgement and be considerate. alan

As has been stated, many variables will affect the drag of a PC. Generally speaking, the most common rule of thumb number I have seen is about 80# at terminal. Just for fun, get a spring scale and attach a PC to it then hang onto the scale outside of a car window. SLOWLY accellerate and observe the scale for as long as you can hang on. I'd bet you'll never get to 120 mph. OK, OK, so this isn't very scientific and you'll most likely dislocate your shoulder, but hey, "guesses are fine" and it will make a good bonfire story. alan

One of the best values for a rig out there, especially entry level. It was way ahead of its' time and has several features that have been incorporated into many of the better known and more popular rigs. Why this rig has remained such a secret puzzles me. I gues that RI has never been very aggressive in marketing it as compared to some of the other big names. The Genera is very rigger friendly. There is always going to be someone who has had a bad experience and will tell of flaps coming open or exposed bridle, etc., but I would consider them to be the exception rather than the rule. Andy was right though, you won't see a lot of them around and therefore the resale value may be weak......but then again, that means you should be able to get one pretty cheap if it is used. In my opinion, it is a bettewr rig and better value than a Dolphin, which by the way is a pretty decent value. alan

With respect to helmets, there is another side to their story. It is indeed great to hear the news of one saving soneone, but a poorly designed helmet also has the potential to injure. They can actually tranfer more energy to the brain than they absorb, especially in the case of frap hats, they can also cause disabling/fatal injuries to the neck and spine, and carbon fiber can shatter into knife-like shards. I'm not against the use of helmets, but I also am wary of jumping on a bandwagon and conferring a blanket endorsement on the basis of a few isolated incidents. I'm not posting this at kizzie92, but thought this might be a good place to throw my thoughts into this thread. Perhaps instead of putting so much emphasis on the helmet, we should be looking at why this happened. Personally, I think a good pin/gear check before exiting will help us avoid having to fall back on helmets/dytters/CYPRES's/ etc.. Maybe just being a little more careful and aware will do more to "save" us than all of the back-ups we use. Just a thought. Best wishes and hopes for the injured jumper, his family and friends. alan

You can generally go both up and down one size. I would advise you to e-mail the manufacture (Sunpath) for a specific answer. alan

...bill, if your frayed Vectran lines are on an FX or VX, I would urge you to consider the X-Mod from Precision. It will cost more, but you will get HMA lines and greatly improved performance, at least in my opinion. Also, in the long run, the rest of the Vectran will need relpacing more often, so the X-Mod actually ends up being less expensive over 800 to 900 jumps. Just a thought. I seem to recall that you have or have had a Safire as well. I don't think that PA is doing an HMA conversion on that canopy though. alan

If your DZ has a test chamber for the Sentinal AAD, you can put it in there for a quick test before jumping. They are relatively easy to disassemble and clean, but it is nice if someone with a little experience is looking over your shoulder. alan