ChangoLanzao 0 #51 December 19, 2005 QuoteSee, charts like this raise questions for my own downsizing. If I were following it, I'd still be under a 230, the same size canopy I used on my first jump. And yet with direct recommendation and permission of my instructors, I'm just getting under a Pilot 188... about 100 jumps ahead of myself per the chart. The low-timer jumper who's under a canopy that might be too small! ...... But the point of this post is that things like this can be confusing, particularly to low-timers who don't know their own abilities... or lack thereof. People can debate the appropriate size of canopies until the cows come home, but until something like this becomes a BSR, instructors and mentors will just keep on doing what they do. And we'll probably keep having the occasional student dig a hole. Quote The more I read this and other threads on this subject the more convinced I'm becoming that charts and graphs should be left to the manufactures. There are far too many variables involved to make the chart approach useful as a BSR or license requirement. Graphs can be more confusing; they make it too easy for people to interpolate their way into a very precise result that has no basis in reality for their particular situation. I'm really starting to think that the most fruitful approach is going to be one that is based on determining, as accurately as possible, whether a given individual can demonstrate that they have the experience and the skills to safely pilot a particular canopy. Quote Share this post Link to post Share on other sites Silverchic 0 #52 December 19, 2005 Isn't it really up to the DZSO or the CI to give the final yay or nay? I mean even if someone is ok to jump a 150 on the chart but has shown consistently that they don't have the skills to land safely then wouldn't the CI/DZSO refuse to let them jump anything smaller than say, a 170/190? If your CI doesn't have confidence in your abilities to land (SAFELY) the canopy you want to jump - then too bad! You don't jump it! I'm planning a trip to NZ and a couple of the dz's I've spoken to are a little wary of me jumping the canopy I'm on (Safire 169) at 40 jumps. I've been jumping this for the last 20 jumps so I'm confident about landing it - I don't try any low turns, swooping or anything like that. And it's still large enough that I'm usually one of the last in the air so I don't really have to worry about people swooping in front of me. I know I still have a LOT to learn about my canopy but I'm planning to be on it for at least another 100 jumps (or more probably). But the point I'm trying to make is that my CI made the decision to let me jump this canopy based on my abilities. Not my jump numbers... If I couldn't demonstrate a text book set up and awareness under canopy consistently he wouldn't have let me jump it! Sorry this turned into "my $1.00" instead of "my $0.02)... How is it that we put man on the moon before we figured out it would be a good idea to put wheels on luggage? Quote Share this post Link to post Share on other sites nathaniel 0 #53 December 19, 2005 QuoteI did a cursory search on the internet for facts & figures about the SCUBA business, unfortunately I found nothing...would you happen to know if there are any good references, online or off? Without wanting to sidetrack this thread, I came across this SCUBA site which has this SCUBA safety forum.I think it makes for a remarkable case of comparative literature.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites kelpdiver 2 #54 December 19, 2005 Quote I wasn't thinking so much about grandfathering so much as the cost of overregulation on people who have yet to join the sport. At least three people I can think of in the last 5 years have told me they abandoned SCUBA (in the US) at least in part due to the hassles of upgrading and keeping their licenses current. It's by no means a scientific measure, but it inspires me to think of how we could avoid overregulating this sport. There is no regulation in the US. There are no licenses to keep current, no FAA that is concerned with out of control divers falling to the bottom. Your friends' problems are something else. If they're in Illinois, they're probably once a year resort divers. Many operators try to milk these customers by insisting they need a refresher dive for $$ if they haven't been diving in X (6 often) months. Some resort divers badly need it, others can know better to avoid such BS. Scuba has been going the opposite direction of the USPA. Courses are easier, with the allowed ages going down further and further, all to attract more potential customers. The wrong direction, imo, but it has not resulting in a change in the accident rate. I do believe it has resulted in people doing easier dives. There's something not possible in skydiving - the need to open the canopy and land yourself never gets easier. ---------------- I think we do this discussion of Brian's chart injustice by focusing on it as a potential regulation as a BSR. The USPA has already indicated a disinterest in doing this, and we've made many long threads arguing it. Instead, why not focus on the merits of it as a guideline. Does it make sense, does it improve upon his earlier more simplistic chart as published in his book. Flesh it out, and even if it remains just a reference, any person or DZ can choose to use it. Quote Share this post Link to post Share on other sites billvon 2,991 #55 December 19, 2005 >Several of us posting in this very thread have exceeded this proposal >and haven't been killed or injured. Of course. You could put every first time jumper on a Stiletto 120 without any additional training, and many of them (likely most of them) would land without serious injury. But it's a bad idea because a large number of them would be seriously injured or killed. Similarly, right now large numbers of jumpers are downsizing too rapidly, and injuring or killing themselves as a result. You need only hang around a gear store for a few days to see how bad this has become; someone with 25 jumps ordering a Sabre2 135 loaded at 1.6 to 1 isn't uncommon. "Hey, Jimmy Swoop got a Sabre2 135 at 100 jumps, and I'm much better than him!" So we have to do something differently. A chart like this is a good start. Quote Share this post Link to post Share on other sites nathaniel 0 #56 December 19, 2005 Quoteit's a bad idea because a large number of them would be seriously injured or killed. There's some risk inherent in jumping out of airplanes. Where do we draw the line between acceptable & unacceptable risk? I'm not looking for an empirical answer, a chart was already used to start this thread. What I'm asking is what basis do we use to decide where the threshold should be.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites kelpdiver 2 #57 December 19, 2005 Quote>Several of us posting in this very thread have exceeded this proposal >and haven't been killed or injured. Of course. You could put every first time jumper on a Stiletto 120 without any additional training, and many of them (likely most of them) would land without serious injury. But it's a bad idea because a large number of them would be seriously injured or killed. Could we avoid using the rare examples as the norm? On this chart, a Sabre2 190 may be outside the limits. Quote Share this post Link to post Share on other sites Ron 10 #58 December 19, 2005 QuoteIt's particularly evident to me when people propose greasing this one through by grandfathering people under their current licenses or canopies, and screwing up only those people who aren't around to express their displeasure--and who may not stay around long enough to reverse it. Two reasons: 1. People can't afford a new canopy if they just bought one. 2. If the person already is jumping the canopy and is not dead they might be OK. Case in point is alcohol laws in the states. If you were able to drink before they raised the law you could still drink. There was not a doubt that it would be better to raise it to 21 period. But you have to balance what is fair and equitable. Same thing here. BTW bring whatever test you want for me....I qualified for a PRO with my Stiletto 107 which is the same canopy I jump every weekend. QuoteAt least three people I can think of in the last 5 years have told me they abandoned SCUBA (in the US) at least in part due to the hassles of upgrading and keeping their licenses current. It's by no means a scientific measure, but it inspires me to think of how we could avoid overregulating this sport. UH I have a Master rating and it costs me NOTHING to keep it. IMO SCUBA is *much* less regulated, but common sense works much better in SCUBA than skydiving."No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334 Quote Share this post Link to post Share on other sites davelepka 4 #59 December 19, 2005 QuoteWhat I'm asking is what basis do we use to decide where the threshold should be. Well, lets start by first acknowledging that there is a problem. Do you agree that the current system is inadequte given the performance potential for the modern canopy? Assuming yes, lets look at how one would 'draw the line' in any case similar to this. The first, and most obvious answer would be to consult availalbe and relevant data. The problem with this as it applies to this situation, is that the only data we have is that of those who have already been invovled in an incident, and even some of that data is incomplete. In order to make a data-driven decision. we would need to know the total number of jumps made, who made them, under what canopies, what conditions, what WL's and the experience of the pilot. Given that this information is not availalbe to us, what is our recourse? The best I can think of is to consult an expert, and rely on their experience to rough out a idea. Take that idea, and pass it around to similaly qualified experts, and see what sticks and what doesn't. The end result is the best we can come up with. Which is what we have here. One thing I tend to notice regarding your posts is that for all of your opposition to certain ideas, you never seem to present any suggestions as to what you believe to be viable solutions. I'm also noticing a pattern that posters who refuse to identlfy themselves or their qualifications, and who seem to always be playing the contrartian, rarely do provide any useful input to the subject at hand. Quote Share this post Link to post Share on other sites MakeItHappen 15 #60 December 19, 2005 QuoteThere's some risk inherent in jumping out of airplanes. Where do we draw the line between acceptable & unacceptable risk? I'm not looking for an empirical answer, a chart was already used to start this thread. What I'm asking is what basis do we use to decide where the threshold should be. For background info see Risk and Safety About Risks For this case (WL restrictions), you'd want to avoid risks that fell into these categories: Severity - Probability Catastrophic- Frequent Critical - Frequent Catastrophic- Probable Critical - Probable Catastrophic -Occasional The 'problem' is that some people think such-n-such scenario (eg 100 jump wonder with a WL > 1.4) is ok and other people think it is not ok. Generally, it is the people with very little experience that think that is ok. One group may think that scenario has a risk of Critical-Remote, when it really has a greater risk. Now consider some lesser evils, say maximum 1.1 WL until 100 jumps. The place you draw the line is in the gray area. Not everyone will agree with what ever is used. Even USPA does not agree with Brian's chart from his book. That's why USPA recommends a maximum WL of 1.0 all the way to 100 jumps. Another consideration that we all should remember is that the probabilities change with training, experience level, number of jumps at a WL, canopy size, canopy type, DA, ability to judge distances and speeds, spatial disorientation, reaction time among other things. In a nutshell, for abc scenario ask what the severity of occurrence and the probability of occurrence is. Then find out where that lies in a risk matrix. Personal risk tolerance (aka safety) is not always the same as society's risk tolerance. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites nathaniel 0 #61 December 19, 2005 Quote In order to make a data-driven decision....We solved the exit separation problem in a data-driven fashion without collecting elaborate statistics. The plane moves at velocity X, an open canopy moves at or below velocity Y, you need 3-5 seconds to detect and react to a potential collision, etc... Like others have posted recently, a first step to understanding the nature of canopy flight would be to identify isolines of a particular level of performance. Say canopy speed on a well trimmed canopy of a particular make, with various weights and with no control input, with 25% input, 50% input, etc. at known density altitudes. How about this next year we all resolve to buy a portable anemometer (froogle search has them for between $50 and $300) and put together our measurements for the canopies we have. Get a few people from each of our dropzones to do a few test runs on as many different combinations of people <-> canopy as is safe / reasonable.QuoteGiven that this information is not availalbe to us, what is our recourse? I don't have the answer for you. The absence of a clear recourse does not justify any.QuoteOne thing I tend to notice regarding your posts is that for all of your opposition to certain ideas, you never seem to present any suggestions as to what you believe to be viable solutions. From time to time I've posted ideas, and they've been shot down duly. You're free to draw any conclusion you want from that... I draw none.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites nathaniel 0 #62 December 19, 2005 Quote Personal risk tolerance (aka safety) is not always the same as society's risk tolerance. Aha, now we are getting somewhere One thing that's confused me (and I think some of the other people in and around here have picked up on it too) is why we're focused on a single threshold, all or nothing, unsafe or (presumably) safe. If we can come up with one chart, we can come up with two or three, lower risk, medium risk, higher risk, etc as guidance and let jumpers at least make an informed choice about how they prefer their skydiving. Every dropzone might not be able to accommodate every jumper...but already today there are compromises made in the course of ordinary business.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites MakeItHappen 15 #63 December 19, 2005 QuoteQuote Personal risk tolerance (aka safety) is not always the same as society's risk tolerance. Aha, now we are getting somewhere One thing that's confused me (and I think some of the other people in and around here have picked up on it too) is why we're focused on a single threshold, all or nothing, unsafe or (presumably) safe. If we can come up with one chart, we can come up with two or three, lower risk, medium risk, higher risk, etc as guidance and let jumpers at least make an informed choice about how they prefer their skydiving. Every dropzone might not be able to accommodate every jumper...but already today there are compromises made in the course of ordinary business. I think you missed another issue that I mentioned. Risk assessment of an identical scenario varies among a group. Generally, an acceptable consensus can be found to make the society happy. I specifically mentioned that newer jumpers tend to under-estimate the risk level of a scenario. That is primarily because they do not have the experience to make good risk assessments. They do not have the off dz landings, high canopy traffic landings, etc. Most new jumpers will ask for guidance and follow it. The ones that do not want to follow what the 'society' tells them will still merrily assume that they are 'special - an exception to the rule'. The fundamental flaw in their thinking is that they assess the risk level improperly, not what risk level they are assuming. Do you see the difference? As for the different charts with risk level denoted---- how about the attached file? .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites nathaniel 0 #64 December 20, 2005 Quote ... Risk assessment of an identical scenario varies among a group. I specifically mentioned that newer jumpers tend to under-estimate the risk level of a scenario. That is primarily because they do not have the experience to make good risk assessments. ... Do you see the difference? I do and I don't. I hear what you are trying to say, but I don't think it matters with respect to physics much whether newer jumpers take more risk due to preference or ignorance. I do think there's ample reason to believe new jumpers are more likely to be both less risk averse (I bet newer jumpers tend to be younger than experienced jumpers--I actually don't know this as fact but it's easy for me to believe) AND less knowledgeable about their risks. So to address the unknown, is there any information on whether the demographic of skydivers has been aging, or growing among the middle aged or older at the expense of the young? I think that having multiple charts would accommodate some of both. I don't want to get into the particulars of exact numbers yet. I think we have greater opportunity that it may seem to gather raw data if we would only pool & coordinate our resources. See the note I had about anemometers and such.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites MakeItHappen 15 #65 December 20, 2005 QuoteI do and I don't. I hear what you are trying to say, but I don't think it matters with respect to physics much whether newer jumpers take more risk due to preference or ignorance. It does matter - a WHOLE lot. Say I asked you to walk across a 10 foot long 2 by 6 board supported by two cinder blocks on level ground. Then I said 'Well, what if the there was a 5000 ft drop in-between the two cinder blocks?' Is the risk the same? Seeing or not seeing that crevasse means a whole lot. QuoteI do think there's ample reason to believe new jumpers are more likely to be both less risk averse (I bet newer jumpers tend to be younger than experienced jumpers--I actually don't know this as fact but it's easy for me to believe) AND less knowledgeable about their risks. So to address the unknown, is there any information on whether the demographic of skydivers has been aging, or growing among the middle aged or older at the expense of the young? I'm pretty sure that the average age of USPA members has floated up in recent years. That is partially because the new jumpers (age-wise) take themselves out of the sport or out of life completely. So the average age creeps up because the new kids die off or cripple-off. We are going to see a missing gap of males that were born in 1975-1995. They keep maiming or killing themselves off. I started jumping when I was 24, so you really can't say that because I'm old (now) that I don't understand the new kids. I am an old skydiver because I actually followed advice from the elders. You know what, some of those 'elders' are still here today and still USPA members and still jump. They bring that age average up. QuoteI think that having multiple charts would accommodate some of both. Well, I added that later. Please re-read the post. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites nathaniel 0 #66 December 20, 2005 Quote Well, I added that later. Please re-read the post. I saw that, and I like the style of it better than an all or nothing proposal, but I still don't want to commit to a quantification yet. Although the second one definitely has an African feel to it My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites justinb138 0 #67 December 20, 2005 Damn.... I hit "Black Death" on your chart about 30 jumps ago. Quote Share this post Link to post Share on other sites MakeItHappen 15 #68 December 20, 2005 QuoteDamn.... I hit "Black Death" on your chart about 30 jumps ago. Give it some time - it is a probability thing after all.... Besides the 'Red line' demarcation is the Germain rule: 0.1 per 100 jumps increment. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites MakeItHappen 15 #69 December 20, 2005 Quote[ I still don't want to commit to a quantification yet. Me neither. But tell me what you think B4 the next BOD mtg because I am one of the ones that fiddles with the lines. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites kelpdiver 2 #70 December 20, 2005 QuoteQuoteDamn.... I hit "Black Death" on your chart about 30 jumps ago. Give it some time - it is a probability thing after all.... Besides the 'Red line' demarcation is the Germain rule: 0.1 per 100 jumps increment. The probability of "black death" for jumpers at 1.1 is pretty damn low, Jan. Virtually non existent, even. These threads would be more useful without such hyperbole. Quote Share this post Link to post Share on other sites mr2mk1g 10 #71 December 20, 2005 For those worried about grandfathering vs. people suddenly being banned from jumping their current canopy; the answer is to make the chart advisory for the first* year and than mandatory from then on (maybe even first 2 years). As everyone would know the published regulations well ahead of time and the fact that they would be mandatory by a known deadline, they will have plenty of time to either upsize or get enough jumps/training to fall within the allowed bracket on their current wing. If the jumper can't get inside their bracket in that time then hell, they probably ARE too far outside their safety brackets and should be prevented from jumping the canopy (or just damn uncurrent anyway and then the same goes) On the other hand, a previous history of hundreds of jumps on a canopy much smaller than allowed by the chart could mean they fell within the individual skills exclusion appended to the chart and may therefore still be allowed to jump their canopy if the S&TA saw fit to sanction it. Quote Share this post Link to post Share on other sites justinb138 0 #72 December 20, 2005 QuoteQuoteQuoteDamn.... I hit "Black Death" on your chart about 30 jumps ago. Give it some time - it is a probability thing after all.... Besides the 'Red line' demarcation is the Germain rule: 0.1 per 100 jumps increment. The probability of "black death" for jumpers at 1.1 is pretty damn low, Jan. Virtually non existent, even. These threads would be more useful without such hyperbole. Yep. I guess I'm going to have to go find a 260 for the next 6 jumps, as my "Black Death" 230 at just under 1.1 isn't survivable until I have 100 jumps. I guess I could just stick to a 280 so it's only a "medium risk". So should I buy a Navigator or a Navigator? Quote Share this post Link to post Share on other sites MakeItHappen 15 #73 December 20, 2005 QuoteThe probability of "black death" for jumpers at 1.1 is pretty damn low, Jan. Virtually non existent, even. The fundamental flaw in new jumpers' thinking is that they assess the risk level improperly, not what risk level they are assuming. This picture has the current USPA suggested WL limits displayed with the risk zones noted. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites justinb138 0 #74 December 20, 2005 I was at medium risk in your chart on my first Aff jump, and was at "High risk" by the time I had my A. If people are going to be expected to follow the chart, the requirements at least need to be reasonable. Quote Share this post Link to post Share on other sites billvon 2,991 #75 December 20, 2005 >If people are going to be expected to follow the chart, the requirements at least need to be reasonable. The possibility exists that your downsizing progression, rather than the chart, is the unreasonable progression. "I didn't die" is not proof of a reasonable progression. Quote Share this post Link to post Share on other sites Prev 1 2 3 4 5 6 Next Page 3 of 6 Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. 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Silverchic 0 #52 December 19, 2005 Isn't it really up to the DZSO or the CI to give the final yay or nay? I mean even if someone is ok to jump a 150 on the chart but has shown consistently that they don't have the skills to land safely then wouldn't the CI/DZSO refuse to let them jump anything smaller than say, a 170/190? If your CI doesn't have confidence in your abilities to land (SAFELY) the canopy you want to jump - then too bad! You don't jump it! I'm planning a trip to NZ and a couple of the dz's I've spoken to are a little wary of me jumping the canopy I'm on (Safire 169) at 40 jumps. I've been jumping this for the last 20 jumps so I'm confident about landing it - I don't try any low turns, swooping or anything like that. And it's still large enough that I'm usually one of the last in the air so I don't really have to worry about people swooping in front of me. I know I still have a LOT to learn about my canopy but I'm planning to be on it for at least another 100 jumps (or more probably). But the point I'm trying to make is that my CI made the decision to let me jump this canopy based on my abilities. Not my jump numbers... If I couldn't demonstrate a text book set up and awareness under canopy consistently he wouldn't have let me jump it! Sorry this turned into "my $1.00" instead of "my $0.02)... How is it that we put man on the moon before we figured out it would be a good idea to put wheels on luggage? Quote Share this post Link to post Share on other sites
nathaniel 0 #53 December 19, 2005 QuoteI did a cursory search on the internet for facts & figures about the SCUBA business, unfortunately I found nothing...would you happen to know if there are any good references, online or off? Without wanting to sidetrack this thread, I came across this SCUBA site which has this SCUBA safety forum.I think it makes for a remarkable case of comparative literature.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites
kelpdiver 2 #54 December 19, 2005 Quote I wasn't thinking so much about grandfathering so much as the cost of overregulation on people who have yet to join the sport. At least three people I can think of in the last 5 years have told me they abandoned SCUBA (in the US) at least in part due to the hassles of upgrading and keeping their licenses current. It's by no means a scientific measure, but it inspires me to think of how we could avoid overregulating this sport. There is no regulation in the US. There are no licenses to keep current, no FAA that is concerned with out of control divers falling to the bottom. Your friends' problems are something else. If they're in Illinois, they're probably once a year resort divers. Many operators try to milk these customers by insisting they need a refresher dive for $$ if they haven't been diving in X (6 often) months. Some resort divers badly need it, others can know better to avoid such BS. Scuba has been going the opposite direction of the USPA. Courses are easier, with the allowed ages going down further and further, all to attract more potential customers. The wrong direction, imo, but it has not resulting in a change in the accident rate. I do believe it has resulted in people doing easier dives. There's something not possible in skydiving - the need to open the canopy and land yourself never gets easier. ---------------- I think we do this discussion of Brian's chart injustice by focusing on it as a potential regulation as a BSR. The USPA has already indicated a disinterest in doing this, and we've made many long threads arguing it. Instead, why not focus on the merits of it as a guideline. Does it make sense, does it improve upon his earlier more simplistic chart as published in his book. Flesh it out, and even if it remains just a reference, any person or DZ can choose to use it. Quote Share this post Link to post Share on other sites
billvon 2,991 #55 December 19, 2005 >Several of us posting in this very thread have exceeded this proposal >and haven't been killed or injured. Of course. You could put every first time jumper on a Stiletto 120 without any additional training, and many of them (likely most of them) would land without serious injury. But it's a bad idea because a large number of them would be seriously injured or killed. Similarly, right now large numbers of jumpers are downsizing too rapidly, and injuring or killing themselves as a result. You need only hang around a gear store for a few days to see how bad this has become; someone with 25 jumps ordering a Sabre2 135 loaded at 1.6 to 1 isn't uncommon. "Hey, Jimmy Swoop got a Sabre2 135 at 100 jumps, and I'm much better than him!" So we have to do something differently. A chart like this is a good start. Quote Share this post Link to post Share on other sites
nathaniel 0 #56 December 19, 2005 Quoteit's a bad idea because a large number of them would be seriously injured or killed. There's some risk inherent in jumping out of airplanes. Where do we draw the line between acceptable & unacceptable risk? I'm not looking for an empirical answer, a chart was already used to start this thread. What I'm asking is what basis do we use to decide where the threshold should be.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites
kelpdiver 2 #57 December 19, 2005 Quote>Several of us posting in this very thread have exceeded this proposal >and haven't been killed or injured. Of course. You could put every first time jumper on a Stiletto 120 without any additional training, and many of them (likely most of them) would land without serious injury. But it's a bad idea because a large number of them would be seriously injured or killed. Could we avoid using the rare examples as the norm? On this chart, a Sabre2 190 may be outside the limits. Quote Share this post Link to post Share on other sites
Ron 10 #58 December 19, 2005 QuoteIt's particularly evident to me when people propose greasing this one through by grandfathering people under their current licenses or canopies, and screwing up only those people who aren't around to express their displeasure--and who may not stay around long enough to reverse it. Two reasons: 1. People can't afford a new canopy if they just bought one. 2. If the person already is jumping the canopy and is not dead they might be OK. Case in point is alcohol laws in the states. If you were able to drink before they raised the law you could still drink. There was not a doubt that it would be better to raise it to 21 period. But you have to balance what is fair and equitable. Same thing here. BTW bring whatever test you want for me....I qualified for a PRO with my Stiletto 107 which is the same canopy I jump every weekend. QuoteAt least three people I can think of in the last 5 years have told me they abandoned SCUBA (in the US) at least in part due to the hassles of upgrading and keeping their licenses current. It's by no means a scientific measure, but it inspires me to think of how we could avoid overregulating this sport. UH I have a Master rating and it costs me NOTHING to keep it. IMO SCUBA is *much* less regulated, but common sense works much better in SCUBA than skydiving."No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334 Quote Share this post Link to post Share on other sites
davelepka 4 #59 December 19, 2005 QuoteWhat I'm asking is what basis do we use to decide where the threshold should be. Well, lets start by first acknowledging that there is a problem. Do you agree that the current system is inadequte given the performance potential for the modern canopy? Assuming yes, lets look at how one would 'draw the line' in any case similar to this. The first, and most obvious answer would be to consult availalbe and relevant data. The problem with this as it applies to this situation, is that the only data we have is that of those who have already been invovled in an incident, and even some of that data is incomplete. In order to make a data-driven decision. we would need to know the total number of jumps made, who made them, under what canopies, what conditions, what WL's and the experience of the pilot. Given that this information is not availalbe to us, what is our recourse? The best I can think of is to consult an expert, and rely on their experience to rough out a idea. Take that idea, and pass it around to similaly qualified experts, and see what sticks and what doesn't. The end result is the best we can come up with. Which is what we have here. One thing I tend to notice regarding your posts is that for all of your opposition to certain ideas, you never seem to present any suggestions as to what you believe to be viable solutions. I'm also noticing a pattern that posters who refuse to identlfy themselves or their qualifications, and who seem to always be playing the contrartian, rarely do provide any useful input to the subject at hand. Quote Share this post Link to post Share on other sites
MakeItHappen 15 #60 December 19, 2005 QuoteThere's some risk inherent in jumping out of airplanes. Where do we draw the line between acceptable & unacceptable risk? I'm not looking for an empirical answer, a chart was already used to start this thread. What I'm asking is what basis do we use to decide where the threshold should be. For background info see Risk and Safety About Risks For this case (WL restrictions), you'd want to avoid risks that fell into these categories: Severity - Probability Catastrophic- Frequent Critical - Frequent Catastrophic- Probable Critical - Probable Catastrophic -Occasional The 'problem' is that some people think such-n-such scenario (eg 100 jump wonder with a WL > 1.4) is ok and other people think it is not ok. Generally, it is the people with very little experience that think that is ok. One group may think that scenario has a risk of Critical-Remote, when it really has a greater risk. Now consider some lesser evils, say maximum 1.1 WL until 100 jumps. The place you draw the line is in the gray area. Not everyone will agree with what ever is used. Even USPA does not agree with Brian's chart from his book. That's why USPA recommends a maximum WL of 1.0 all the way to 100 jumps. Another consideration that we all should remember is that the probabilities change with training, experience level, number of jumps at a WL, canopy size, canopy type, DA, ability to judge distances and speeds, spatial disorientation, reaction time among other things. In a nutshell, for abc scenario ask what the severity of occurrence and the probability of occurrence is. Then find out where that lies in a risk matrix. Personal risk tolerance (aka safety) is not always the same as society's risk tolerance. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites
nathaniel 0 #61 December 19, 2005 Quote In order to make a data-driven decision....We solved the exit separation problem in a data-driven fashion without collecting elaborate statistics. The plane moves at velocity X, an open canopy moves at or below velocity Y, you need 3-5 seconds to detect and react to a potential collision, etc... Like others have posted recently, a first step to understanding the nature of canopy flight would be to identify isolines of a particular level of performance. Say canopy speed on a well trimmed canopy of a particular make, with various weights and with no control input, with 25% input, 50% input, etc. at known density altitudes. How about this next year we all resolve to buy a portable anemometer (froogle search has them for between $50 and $300) and put together our measurements for the canopies we have. Get a few people from each of our dropzones to do a few test runs on as many different combinations of people <-> canopy as is safe / reasonable.QuoteGiven that this information is not availalbe to us, what is our recourse? I don't have the answer for you. The absence of a clear recourse does not justify any.QuoteOne thing I tend to notice regarding your posts is that for all of your opposition to certain ideas, you never seem to present any suggestions as to what you believe to be viable solutions. From time to time I've posted ideas, and they've been shot down duly. You're free to draw any conclusion you want from that... I draw none.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites
nathaniel 0 #62 December 19, 2005 Quote Personal risk tolerance (aka safety) is not always the same as society's risk tolerance. Aha, now we are getting somewhere One thing that's confused me (and I think some of the other people in and around here have picked up on it too) is why we're focused on a single threshold, all or nothing, unsafe or (presumably) safe. If we can come up with one chart, we can come up with two or three, lower risk, medium risk, higher risk, etc as guidance and let jumpers at least make an informed choice about how they prefer their skydiving. Every dropzone might not be able to accommodate every jumper...but already today there are compromises made in the course of ordinary business.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites
MakeItHappen 15 #63 December 19, 2005 QuoteQuote Personal risk tolerance (aka safety) is not always the same as society's risk tolerance. Aha, now we are getting somewhere One thing that's confused me (and I think some of the other people in and around here have picked up on it too) is why we're focused on a single threshold, all or nothing, unsafe or (presumably) safe. If we can come up with one chart, we can come up with two or three, lower risk, medium risk, higher risk, etc as guidance and let jumpers at least make an informed choice about how they prefer their skydiving. Every dropzone might not be able to accommodate every jumper...but already today there are compromises made in the course of ordinary business. I think you missed another issue that I mentioned. Risk assessment of an identical scenario varies among a group. Generally, an acceptable consensus can be found to make the society happy. I specifically mentioned that newer jumpers tend to under-estimate the risk level of a scenario. That is primarily because they do not have the experience to make good risk assessments. They do not have the off dz landings, high canopy traffic landings, etc. Most new jumpers will ask for guidance and follow it. The ones that do not want to follow what the 'society' tells them will still merrily assume that they are 'special - an exception to the rule'. The fundamental flaw in their thinking is that they assess the risk level improperly, not what risk level they are assuming. Do you see the difference? As for the different charts with risk level denoted---- how about the attached file? .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites
nathaniel 0 #64 December 20, 2005 Quote ... Risk assessment of an identical scenario varies among a group. I specifically mentioned that newer jumpers tend to under-estimate the risk level of a scenario. That is primarily because they do not have the experience to make good risk assessments. ... Do you see the difference? I do and I don't. I hear what you are trying to say, but I don't think it matters with respect to physics much whether newer jumpers take more risk due to preference or ignorance. I do think there's ample reason to believe new jumpers are more likely to be both less risk averse (I bet newer jumpers tend to be younger than experienced jumpers--I actually don't know this as fact but it's easy for me to believe) AND less knowledgeable about their risks. So to address the unknown, is there any information on whether the demographic of skydivers has been aging, or growing among the middle aged or older at the expense of the young? I think that having multiple charts would accommodate some of both. I don't want to get into the particulars of exact numbers yet. I think we have greater opportunity that it may seem to gather raw data if we would only pool & coordinate our resources. See the note I had about anemometers and such.My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites
MakeItHappen 15 #65 December 20, 2005 QuoteI do and I don't. I hear what you are trying to say, but I don't think it matters with respect to physics much whether newer jumpers take more risk due to preference or ignorance. It does matter - a WHOLE lot. Say I asked you to walk across a 10 foot long 2 by 6 board supported by two cinder blocks on level ground. Then I said 'Well, what if the there was a 5000 ft drop in-between the two cinder blocks?' Is the risk the same? Seeing or not seeing that crevasse means a whole lot. QuoteI do think there's ample reason to believe new jumpers are more likely to be both less risk averse (I bet newer jumpers tend to be younger than experienced jumpers--I actually don't know this as fact but it's easy for me to believe) AND less knowledgeable about their risks. So to address the unknown, is there any information on whether the demographic of skydivers has been aging, or growing among the middle aged or older at the expense of the young? I'm pretty sure that the average age of USPA members has floated up in recent years. That is partially because the new jumpers (age-wise) take themselves out of the sport or out of life completely. So the average age creeps up because the new kids die off or cripple-off. We are going to see a missing gap of males that were born in 1975-1995. They keep maiming or killing themselves off. I started jumping when I was 24, so you really can't say that because I'm old (now) that I don't understand the new kids. I am an old skydiver because I actually followed advice from the elders. You know what, some of those 'elders' are still here today and still USPA members and still jump. They bring that age average up. QuoteI think that having multiple charts would accommodate some of both. Well, I added that later. Please re-read the post. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites
nathaniel 0 #66 December 20, 2005 Quote Well, I added that later. Please re-read the post. I saw that, and I like the style of it better than an all or nothing proposal, but I still don't want to commit to a quantification yet. Although the second one definitely has an African feel to it My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski? Quote Share this post Link to post Share on other sites
justinb138 0 #67 December 20, 2005 Damn.... I hit "Black Death" on your chart about 30 jumps ago. Quote Share this post Link to post Share on other sites
MakeItHappen 15 #68 December 20, 2005 QuoteDamn.... I hit "Black Death" on your chart about 30 jumps ago. Give it some time - it is a probability thing after all.... Besides the 'Red line' demarcation is the Germain rule: 0.1 per 100 jumps increment. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites
MakeItHappen 15 #69 December 20, 2005 Quote[ I still don't want to commit to a quantification yet. Me neither. But tell me what you think B4 the next BOD mtg because I am one of the ones that fiddles with the lines. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites
kelpdiver 2 #70 December 20, 2005 QuoteQuoteDamn.... I hit "Black Death" on your chart about 30 jumps ago. Give it some time - it is a probability thing after all.... Besides the 'Red line' demarcation is the Germain rule: 0.1 per 100 jumps increment. The probability of "black death" for jumpers at 1.1 is pretty damn low, Jan. Virtually non existent, even. These threads would be more useful without such hyperbole. Quote Share this post Link to post Share on other sites
mr2mk1g 10 #71 December 20, 2005 For those worried about grandfathering vs. people suddenly being banned from jumping their current canopy; the answer is to make the chart advisory for the first* year and than mandatory from then on (maybe even first 2 years). As everyone would know the published regulations well ahead of time and the fact that they would be mandatory by a known deadline, they will have plenty of time to either upsize or get enough jumps/training to fall within the allowed bracket on their current wing. If the jumper can't get inside their bracket in that time then hell, they probably ARE too far outside their safety brackets and should be prevented from jumping the canopy (or just damn uncurrent anyway and then the same goes) On the other hand, a previous history of hundreds of jumps on a canopy much smaller than allowed by the chart could mean they fell within the individual skills exclusion appended to the chart and may therefore still be allowed to jump their canopy if the S&TA saw fit to sanction it. Quote Share this post Link to post Share on other sites
justinb138 0 #72 December 20, 2005 QuoteQuoteQuoteDamn.... I hit "Black Death" on your chart about 30 jumps ago. Give it some time - it is a probability thing after all.... Besides the 'Red line' demarcation is the Germain rule: 0.1 per 100 jumps increment. The probability of "black death" for jumpers at 1.1 is pretty damn low, Jan. Virtually non existent, even. These threads would be more useful without such hyperbole. Yep. I guess I'm going to have to go find a 260 for the next 6 jumps, as my "Black Death" 230 at just under 1.1 isn't survivable until I have 100 jumps. I guess I could just stick to a 280 so it's only a "medium risk". So should I buy a Navigator or a Navigator? Quote Share this post Link to post Share on other sites
MakeItHappen 15 #73 December 20, 2005 QuoteThe probability of "black death" for jumpers at 1.1 is pretty damn low, Jan. Virtually non existent, even. The fundamental flaw in new jumpers' thinking is that they assess the risk level improperly, not what risk level they are assuming. This picture has the current USPA suggested WL limits displayed with the risk zones noted. .. Make It Happen Parachute History DiveMaker Quote Share this post Link to post Share on other sites
justinb138 0 #74 December 20, 2005 I was at medium risk in your chart on my first Aff jump, and was at "High risk" by the time I had my A. If people are going to be expected to follow the chart, the requirements at least need to be reasonable. Quote Share this post Link to post Share on other sites
billvon 2,991 #75 December 20, 2005 >If people are going to be expected to follow the chart, the requirements at least need to be reasonable. The possibility exists that your downsizing progression, rather than the chart, is the unreasonable progression. "I didn't die" is not proof of a reasonable progression. Quote Share this post Link to post Share on other sites
