alan

All manufacturers do not trim all canopies the same and mfgr's trim some models differently. Typically, most canopies are trimmed slightly nose down from best glide. They do this for a variety of reasons, including but not limited to, attaining desired opening characteristics, higher pressurization, and stability. Some canopies are trimmed closer to best glide than others. alan

Was it indeed a lineover or a slider hang up? Did he discuss whether or not a hook knife would have helped in his situation? If yes, why did he use/not use it? FWIW, I'm not trying to bash or promote hook knives, just get some real info regarding how valid their use is for dealing with a reserve lineover. alan

When I started getting interested in "hook turns" back in the early 90's, everyone was doing toggle turns. Not much advice. "Just pull the toggle all the way down and make sure you are higher than normal," was about the extent of it. I'd fly a normal pattern and gradually got more aggressive on the last 90 turn. Gradually, I learned to do it higher and as my confidence built, the 90's slowly grew into 180 degree turns. No one around my DZ was talking about "sight picture" yet. I'm not sure when or where that was coined. Using my eyes and experience along with the wrist alti led to more consistent swoops. Along the way, I lost quite a bit of skin and "bounced" several times. Just dumb luck that I never broke anything......or worse. As I became more proficient, I began to experiment with front risers and began reading about more experienced jumpers recommending them as safer and more efficient. Not everyone was convinced. I took a step back when learning front riser approaches. I went a route similar to the one described by billvon above, flying a "normal" pattern and using double fronts on final. I found myself flying the whole pattern lower so that when I finished my 90 onto to final, I could go immediately into fronts and be in the swoop before the riser pressure got to high for me to hold them down. Only when I started doing gradual front riser turns onto final did I realize I needed to start them with more altitude. Cool, no pain this way and was soon doing carving 180's. All the while I was downsizing and going to more HP canopies as they started to gain in popularity, maybe around 1993 or '94. By '97 I was jumping a 136 Jedei at 1.7 and thought it would be cool to move onto 270 degree approaches. There still wasn't much available at that time in trems of advice, mostly "just do what ever you are going to do but do it a lot higher." I decided to experiment way up high. H&P from 10.5 and set up on a heading at a specific altitude. Then I experimented with turns and when the canopy planed out. I was looking for a pattern of how much altitude my canopy would loose in an aggressive 270 degree front riser turn. Then I took that information and used an approach similar to what Rhino describd above. I started out higher than what my tests had shown me and sure enough, I was finishing my 270's too high. Not being patient, I then tried going lower, about 400' as I recall. I found myself having to bail out of turns from that alti. Of course I hadn't given any thought to density altitude. Things were getting better now as far as info. Blade running was catching on and organized swoop meets started to happen. Information was starting to be shared. In 1999, I started to jump the new x-braced canopies starting with an FX. By then 360 and 540 and even some 720 degree appraoches were being used by a growing number of jumpers. In Oct of '99 I made jump number 1201 on my 89 VX and it wasn't long before I wanted to do carving 360 degree approaches, useing rear risers for the surf, and stearing with harness input. Advice from the manufacturers reps still wasn't much more than "whatever you decide to do, make sure you do it real high." Back up to altitude and do some experimenting. It did not take more than a few jumps using my wrist alti to realize that an aggressive, carving 360 front riser approach on this canopy would nead nearly 1000' of altitude. The front riser pressure was so high on that canopy that I learned to set-up in brakes. During slow flight the pressure was fairly light and it much easier to transition to aggressive fronts. What a hodge podge of experimenting, improvising, reading, researching, observing, and talking to others. Today, I advise "experienced" canopy pilots to make a lot of H&Ps up high and learn all of the flight characteristics and ranges of the canopy. Make several jumps just noting how much altitude it looses in 180, 270, and 360 turns. Once that is mastered, start with the straight in front risers and progress slowly up to what ever their goal is. That is a very over-simplified version because there is so much to learn and that really needs to start at jump number 1. alan

I liked this method posted by billvon over in S & T a while back. Unfortunately we are a shortcut society. Some pilots want to jump right in with 90's or even 180's. alan

And the PM feature is still working. alan

I would hope not, since I believe you either wrote the manual or played a mojor role in its' development.

I have found stuff like Hook has pointed out here coming from the bigger shops with master rigger seals on it. The last time it was reserve brake lines not tied on evenly. alan

Ok, for the Very experienced swoopers, please share with the newer pilots how you went about learning your "sight picture" and what (if anything) you would do different in teaching it to someone else. alan

To add some balance and depth to the discussion. It would be nice if it was just between more experienced canopy pilots, exchanging information. But, as I am sure you know, you can't control who reads the thread. There are people with 400 jumps, some even less, who will read it because they are interested in learning to swoop. The altitudes you were given in the responses ranged from educated guesses to digital readouts to unspecified sources. How is one, including yourself, to evaluate and judge their accuracy and therefore usefulness? The responses also seemed to contradict what has been posted in Incidents/Safety and Training regarding the usefulness of altimeters as tools. I apologize if my posts eroded your nice little exchange of information, I thought I was contributing. From my perspective, the posts by Diablo Pilot led it into a debate on semantics and contributed nothing of substance. I feel my replies were appropriate. I don't think any of us ever stop learning, regardless of jump numbers and experience and that is how I interpreted your post based on your profile. I hope this clears up the confusion you have about my motives. Chris, if you desire any further clarification, perhaps a PM would be the most appropriate vehicle. alan

I agree. That is pretty much the point I have been trying to get across. The alti is a tool and and it is OK to use it. I do not agree with giving out the advice that one should never use an alti when learning the correct sight picture for initiating a swoop landing as was done in a different forum/thread a while back. I think one can learn to do it safely without an alti, I just don't believe the use of a tool like an alti should be dismissed entirely. The comments in this thread seem to support that notion. alan

It looks as if you have been a little close minded and chose the one definition that suited your purpose(and a weak interpretation of it as well). Close minded is how I would describe your position with respect to the use of an alti as a tool for learning the correct sight picture for swoop approaches. My position was, and is, that it is OK to use the no alti approach described by billvon in another thread/forum. I also believe it is OK to use it as a tool. I do not believe either method should be excluded/discounted when giving advice about learning. I believe we each learn a little differently and should tailor or methods to our individual needs. The majority of the people that have responded "so far" have indicated they use or have used an altimeter of some sort when setting their approach to 270 degree approach. None, so far, including myself, have indicated that they have relied soley on an alti or wish they hadn't used it. Until a majority of the responces indicate that they didn't use an alti when learning, or don't currently use one, and/or express an opinion that they shouldn't have, I'll stand by my opinion. 3 entries found for consensus. con·sen·sus ( P ) Pronunciation Key (kn-snss) n. An opinion or position reached by a group as a whole: “Among political women... there is a clear consensus about the problems women candidates have traditionally faced” (Wendy Kaminer). See Usage Note at redundancy. General agreement or accord: government by consensus. -------------------------------------------------------------------------------- [Latin cnsnsus; see consent, from past participle of cnsentre, to agree. See consent.] Source: The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2000 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved. consensus \Con*sen"sus\, n. [L. See Consent.] Agreement; accord; consent. That traditional consensus of society which we call public opinion. --Tylor. Source: Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc. consensus n : agreement of the majority in sentiment or belief [syn: general agreement] Source: WordNet ® 1.6, © 1997 Princeton University alan

Doesn't the harness/container manual take precedent over the canopy manual? alan

Well then, based on what has been posted in this thread "so far", what would you say the consensus has been? Please use some quotes from this thread to support your answer, I'm curious as to what I missed. I am aware of your opinions from the other thread. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=756776;#756776 alan

So, it looks like the consensus so far is that it is OK for jumpers learning swooping to use an alti as a tool to help learn the sight picture and then continue to use it as confirmation. The better the alti (tool), the better the result. I was confused by the guy over in incidents/safety and training posting that one should never use an alti to learn the sight picture for setting up the entry. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=750667;sb=post_latest_reply;so=ASC;forum_view=forum_view_expanded;#750667 http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=752237;#752237 alan

So, other than the guys with Neptunes, how do you come up with the altitude estimates you are using? I'm aware that we aren't looking at altimeters during this phase of the landing because we have to keep ours eyes open for traffic. Is everyone just that good at estimating these distances to +/- 50' from altitudes of 300' to 900' and a moving sight picture that is accelerating to more than 60 mph? I can recall someone posting in another thread that an error of 10 or 20 feet can have fatal results, even advised someone learning to swoop to never use an altimeter for learning the set up. What were we using before Neptunes? alan

http://usff.com/hldl/report/3rdEditiona.html The source is referenced here, it should be sufficient for you to find the original if you wish. Not the gospel by any means, but enough for me to ask questions. I'm not anti helmt by any means, but have a problem with the mentality of not questioning their effectiveness and or safety. Apparently there are those that feel we should just all agree that they are a good thing based on their personal observations or experiences and let it go at that. Who needs real empirical data to eveluate. I guess we can all agree that the Earth is flat and the Sun orbits the Earth. Tangential or rotational forces to the head/neck are the cause of the majority of head impact injuries. Most are in the frontal and lateral areas, with very few from the back. Ah hell, here is the link to the report. http://www.kena.net/phd/docs/deadpilot.htm alan

http://usff.com/hldl/report/3rdEditiona.html http://www.kena.net/phd/docs/deadpilot.htm alan

The Navy did some studies years ago, may not be relevant. They concluded that the helmets Navy pilots were wearing at the time were the cause of death during high speed ejections. I believe they used the terminology of hangman's noose syndrome. alan

In principal, I agree. Now I can't help but wonder, are skydivers more likely to sue than an injured BMXer, for example? Seems as if with the large market thay already have and the relatively extreme activities the target markets have, wouldn't the legal issues have surfaced by now? Maybe they have and they just don't want to add to them. Would not be logical to me, but then who knows. alan

Pro-Tec Ace Fullface BMX Helmet Item no: 1058367 OUR PRICE: $59.99 Features Hand-laminated, 1-piece, multi-layered carbon/Kevlar® Ultra-lightweight materials and design Head ventilation channels Moto-x style visor Certified to ASTM, CPSC & CE helmet standards This is from the the information provided by Aggiedave and Ian. $60 Hmmmmmm...... It is too bad that there isn't an organization representing skydivers that could put pressure on the industry to produce a lightweight, carbon/kevlar helmet to some standards and for $60 no less! alan

"My face left a four inch divot where my factory diver hit. " "There is no way you can tell me that the helmet was a bad thing - if it weren't for that helmet, I would most certainly not be here today. " It would appear that the Pro-tec is not the only helmet that offers protection, or at least if you are going to collide face first. It seems to me that we as skydivers don't want an industry standard for safety in our helmets, like the DOT motorcycle helmets. Seems as if their stats are good enough to satisfy us and we don't want to put pressure on the fly by night manufacturers looking to make a quick easy dollar. I wonder how using a safety device such as a helmet for a camera mounting platform affects its' performance in a collision? Now I wonder about all of those motorcycle stats. Do they routinely attach cameras to their helmets? How would that affect those stats? One more question. About that face induced divot with the facory diver, would a Pro-tec offered the same level of protection, being that it is open faced? There is always a better way, we just have to find it. alan

You must mean acceleration injury or it can also be expressed as a negative acceleration injury. It was pointed out to me in no uncertain terms a short time ago in a different forum here that deceleration is just a layman's term and that from a Physics perspective they are the same thing, with no real difference. Apparently it has something to do with relative movement. I was fairly well called a fool and/or a common troll for suggesting that one does not accelerate up to a stoplight. At any rate, I think that if we are going to endorse and promote the use of helmets, we ought to at least encourage the manufactuers to provide some testing data and adhere to some type of standard. Of course that will mean testing, liability issues, etc., and ultimately raise the cost of a helmet. That's OK though because if it means saving a life then it is cheap insurance. You know, like a Cypres. People seem to have no problem with paying $1000 for the benefits they offer. I also think it is unfair to limit the discussion to collisions with the ground while using a high performance canopy. Collisions occur with aircraft tails, other skydivers in freefall, and even big slow canopies can go fast enough to cuasa a head injury. alan

Thanks, I'm glad you found it informative. I realize you have gotten a lot of information from Scott Miller, and he is an abolute good source......better than me. I don't think there is as much conflicting information as just insufficient communication. Please feel free to share what I have posted with Scott and get his feedback on it. Scott presents info based on PD canopies and I agree with him, they do give the best glide in deep brakes. What I think did not get communicated is that even the Stiletto, for example, has a point where going to deeper brakes causes it to sink more and erode the glide ratio and yet deeper brakes results in a stall. Yes, I don't think there is a "one size fits all" solution to getting the best glide. A glance at several aircraft manuals might verify that. Some may specify putting some degree of flaps and a best glide speed for best glide in a loss of power situation. Others don't, but just give a best glide airspeed. Think of the rear risers as serving the function of the elevator and the brakes as the flaps. My intent is not to give information that conflicts with anything you have gotten from people like Scott, but to supplement or expand on it and perhaps even clarify. alan

The idea is to find the wing loading without weights that gives the best glide for the distance and carving competitions, etc.. The weights are added for the speed competition where the length of the glide is not important. alan

The beginning of yet another canopy myth. Every canopy in neutral and static conditions has an L/D, or lift to drag ratio. The L/D is also often commonly referred to as the glide ratio. The ratio will vary from one canopy design to another. Let's say a typical sport canopy today has a glide ratio or L/D of about 4/1. That means in neutral flight under static conditions, the canopy will travel forward 4 feet for every foot it sinks. Like most every aspect of areodynamics, if you change one element, it has an effect on another. In this case, going into brakes has the effect of changing the airfoil, which in turn has an effect on the L/D of the canopy. With most modern sport canopies in use today, a certain amount of brakes will have the effect of improving the L/D, but that can depend on the manufacturer and specific canopy model. Once again, as with most other aspects of aerodynamics, there is a point where changing something too much will lead to a different result than what a similar change, but to a lesser degree, will yield. In this case, if you add too much brake, the L/D will will stop improving and decline, eventually to the point of a stall where the canopy ceases to fly. You see, any airfoil will stall (cease to create enough lift to fly) when it exceeds its' critical angle of attack for any given airspeed. Deeper brakes give the airfoil more camber and a steeper angle of attack and thus more lift, but that lift comes with a cost. When you create more lift, you create more drag. More drag results in less forward speed and so at some point you add enough brakes to where the cost of the added lift is so much drag that the airfoil, canopy, can no longer generate enough lift to fly at the angle of attack and airspeed at that point. The angle of attack is simply the angle at which the relative wind hits the airfoil as measured along its' chord line. Another option for effecting a change in your canopy's L/D would be to change the trim angle. This can be done in flight by pulling down on the rear risers, or even the front risers, depending on whether you want to increase or decrease the AOA. Again, too much, and you may distort the airfoil, resulting in poorer performance or loss of enough airspeed to create a stall, just like with too much brakes. Yet another option is to combine inputs. Leave your brakes in the set position and then spread or pull down on the rear risers. The bottom line is, get to know your canopy. Have fun and experiment to see what works best on your canopy and gives you its' best glide ratio. A lot of what you will perceive will be "seat of the pants" and therefore pretty subjective, but if you play around enough, your impressions should become reasonably accurate. Then you'll buy a different canopy and you can learn how it will perform! Why does what method you use vary from model to model and perhaps more noticeably from manufacturer to manufacturer? Because of variations in the design. Such things as the airfoil, trim angle of the canopy, planform, contruction, aspect ratio, and even brake design. I hope this helps. alan