RiggerLee

Why an G4? This is just my opinion but I prefer the G3. I don't like any of the changes that they made between the G3 and the G4. Again this is totally my opinion but I think they let some marketing guy dictate all of the "improvements" made to what was a very good container. Many of the bells and whistles are non functional and some of them are detrimental such as the change to the reserve bag which serves no functional purpose and reduces the volume it may contain. I also do not like some of the changes to the pattern set that they have made to try to offset there errors. I could go on but you get the idea. This is just my opinion but get a G3. It's one of those cases of them getting it right the first time. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

There isn't any thing special about the housing. It's the puller unit. It has a tight cylinder and piston with O-rings forming the seal. It also has the cable on the other end passing through another seal formed by an o-ring compressed between two threaded plugs clamping it around the cable. Both could cause an increase in pull force. Particularly the seal around the 7*7 cable. The o ring could get compressed into the rough surface of the cable with temp, age, chemical issues harden and create a hard pull. Is it really a problem? I don't know, but I think it could be. I don't think it's insurmountable but it does raise questions. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Is it really so impossible to put a after market puller on an AAD? Please correct me if I'm wrong but no one not cypress not vigil, no one makes their own cutters. I was under the impression that all of these were contracted to their specs from stand alone firms specializing in ballistic cutters. How is this really different? It's going to have to evolve a little bit beyond Sherman's home made prototypes It will have to be tested just like the original cutters. It will take money but there is enough evidence of the short comings of cutter activated deployments to make it desirable as an option. It might take a year but I can see this happening. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

How would that work with the QC and materials tracking system required for the TSO? How could you write it up in a way that they would accept with out any ability to get testing specs, tracking, or certification for any of the materials? Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

You have to have something to push or pull against. And it needs to be solid. Back when pin pullers were in vogue they would use a metal clamp to hold the end of the housing. Not just tacking. If it slips, breaks, or comes lose you're fucked. Often they would use a metal plate to reinforce the top flap so that there would be no give and to provide a solid mounting for the housing of the puller. A lot of the current rig as they are designed today to not provide that kind of firm footing. A lot of the housings do not even reach to the top flap. They have a... soft mounting farther forward on the yoke. Changing that would be a significant alteration not just a simple housing replacement. It could be done but it's not trivial. The micro puller style of design, because it provides it's own perches, eliminates that need to tack, bolt, mount the puller or housing. Just thread it through and you're done. It also has the potential to be completely sealed. With the cable and charge at one end and the piston at the other it can be completely sealed just like a cutter. Much simpler the this business of having a Y with a gas port. Much smaller and cleaner. And I think a modern version could be even smaller and sleeker. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Not really the same. You are trying to tack or mount the puller to the flap. It makes you dependent on that instillation for your perches to pull or push against. The micro puller was self contained acting between the loop and the flare of the pin. It was not reliant on tacking. I think it could be made a bit cleaner and more stream lined particularly at the piston end but I think it could also be mounted with no alteration of any kind as ether a puller or a pusher simply by turning it around. I think it would work for most things with out the need for multiple variants. The only exception would be like a strong tandem. For that I would build one with a pig tail It plugs into the AAD the next is a standard one that would plug into it. You could daisy chain ten of them if you had to but it's hard to imagine a rig that would need that. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Some one posted a link to the other thread I'm not sure if people looked at it. I keep coming back to it. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?do=post_attachment;postatt_id=141070; A design like this seems better then all the things we've been talking about. Are there any real disadvantages to it? Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

The bad news dude is that this can of worms you are opening is a binary solution set. It's ether black or white. Legal or illegal. And there is no leeway in the fact that there are tens of thousands of units so installed out in the field. That would only make the lawyers salivate all the more. 85% of all the rigs in the world are un airworthy and illegal to jump. Now right now this very minute. It doesn't mater if there is a fatality or not. Every jump is a violation. It's a violation for the jumper. It's a violation for the pilot. It's a violation for the rigger. It's up to a thousand dollars fine per jump. And if this is found to have been the case, say in the event of a accident, Then I shudder to think what a lawyer would make of the way you have all knowingly conspired to suppress this knowledge for years to protect your profits. That bloody lump cartilage on the floor, that's your nose. Would you like to rethink this position? Because you can't dance around it. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Interesting question. All the force that is applied to the pin must be transferred through the housing unless you try to fix the cutter in some which has it's own issues. The force is in compression. I'm not sure exactly how the coil of the housing fits together. I think it would be more then strong enough but I don't think I've ever seen numbers for the failure point. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I hear serious tap dancing in you're reply. I think you are actually going to have to make a choice on your position here. I just don't see why this has to be made an issue. With the track record of the cypress and vigil cutter I don't believe there is a bases for you statement. But if this truly is your belief then stand up and own it and lead the whole industry in to a new era... Personally I think you would be cutting your own throat but you've never been adverse to falling on your own sword. You are a major manufacturer. This is a public forum for the whole industry. It may not be on letter head but a lot of people are lessening to what you say. You can't just attack other peoples products and then compound the insult by trying to side step the consequences of such a statement. I'm sorry but you need to ether commit to and defend this statement or with draw it. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

That's actually a good argument for the micro puller design. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I've been watching how this facet of the conversation has been developing. You have made some very strong and unambiguous statements about your feeling concerning the legality of cutter instillations on TSO'd containers. Just to be clear are you saying that it is illegal to install any cutter based AAD in a Racer sport or tandem rig? Are you saying that the presents of a cutter based AAD voids the TSO of the Racer and makes it un airworthy and illegal to jump? Are all Racers grounded till the cutters are removed? Since this has been your position for years ever since the Argus debacle. Why did you not make this announcement then, or did I miss the memo making rigs equipped with Cypreses and Vigils un airworthy? Please give us a clear policy statement on this. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Perhaps because wing loading is not a fixed parameter of the design. In fact you might be able to say that size, loading, and density altitude are all a juggling act that could in theory balance out in the same way at radically different numbers. It's kind of like Reynolds Numbers where you could get equivalent performance at a relative scale. It's just not the place where I would start to examine the fundamental characteristics of a design. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Found his page http://pcprg.com/ Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Have you contacted Gary Peek? He's on here I think under the name PEEK http://www.dropzone.com/cgi-bin/forum/gforum.cgi?username=peek; He has actually taught classes in parachute design. He was involved in the early efforts to put accelerometers and load cells on rigs. He has a lot of his data and reports on his web site. There's another group you should try. I'm brain locking, can't think of their name, but they were at the last PIA symposium giving lectures. They built a load cell/data acquisition system that is being used by a number of companies in their certification process and to prosue government contracts. They have the best equipment around. They are part of or associated with Performance Design. So if you talk to the right people there they can help you. See if they or any of their client's, like PD, would be willing to share some data. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Vague, yah a little vague. But more then that a little ambitious. You've listed half a dozen different things that you might do a study on any one of which would probable be enough to keep you busy. You've casually tossed around a number of questions any one of which would actually entail solving a number of non trivial problems. If you're looking for advice there are people here that can give it to you. If you're looking for information, there is some. A lot of it resides within companies that make their living off of it. And some of it just isn't around. A lot of people have tried to study and analyze parachutes with only limited success. They are not as... nice as, for example, an airplane. It's hard to do a model when you have trouble even saying what shape they are. I mean that's pretty basic and with the... Let's just call it aero elastic issues, even that is non trivial. Up till recently there wasn't even any "good" experimental data on them. There has been some work done in a few wind tunnels large enough to hold a scale model. Gyro did some of that. Recently there has been a lot of work done with data gathering putting instrumentation on to canopies. It's kind of the next big frontier that people are looking at. For the first time we are starting to get measurable quantifiable data but I don't think there is that much of it yet. All though there are people doing it most of them don't seem to be all that organized. There way a guy from Europe that seemed to be accumulating some pretty good data. I met him at PIA, he gave a lecture four five years ago. If he pursued it then he might have some good GPS date on flight paths, turn and sink rates, and speeds for you. So my advice is that if you're going to try to do some thing... theoretical, like a model, then pick ONE problem or question and try to create some thing to examine it. If on the other hand you're looking to do an analysis of empirical data, start by cheating. Look around and find some data that you think you can work from, that will actually be the hardest part, then based on what is available to work with define what you want to try to study. I know that seem back ward but it's the only way you'll avoid running into a dead end. Just some thoughts. Pick a question and we'll try to help. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

This guy is kind of working through a little home project where he's building his own canopies. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4342216;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread There's a lot of discussion where he's trying to understand some of these issues. As to what makes a canopy the canopy that it is... The shortest answer by my guess... 1. trim angle 2. aspect ratio 3. airfoil thickness There can be other factors but I think those are the driving characteristics. Zp allows you to have a higher internal pressure with out leaking too much air through the surfaces, higher wing loading. Cross bracing reduces the distortion in the wing that reduces the span and makes it less dependent on pressurization to maintain it's shape. Better low speed performance allowing you to land at higher wing loadings. It also allows you to get by with a thinner air foil. Changes to the nose reducing the size of the openings can reduce drag and improve air flow but they can also lead to issues the stagnation point on the front of the canopy. Line length can affect the dynamic characteristics of the canopy. So there are a lot of things that feed into it but I think they all feed back in to the ones above. What are you really asking? Define your question better and we'll refine our answers. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I don't buy the, "Cutters are illegal", thing. I call bull shit. There were problems with the Argus cutter. Bad design, bad production, defective? I don't pretend to know the full story but it does not stand to reason that you can condemn all cutters. There is a long history of success with them. As to the performance of the rig when fired by the cutter, since there are no standards for it I see no requirement that it function in the same manor or to the same performance standards. I'm sure we would all like good performance from the AAD and things have been done to improve that and to give more margin for them to operate in. None of this makes cutters in any way illegal. A well designed cutter in no way interferes with the normal operation of the rig. On the other hand you are talking about using this adjustable seal around the rip cord. A design which WILL crate a higher pull force. And could possible have issues with temp, age, chemicals, etc. One of the fundamental test in the TSO is the pull force on the reserve. You are adding some thing which will change that number and could possible drastically affect that number and you're ability to pull the rip cord. I'm not saying that it can't be made to work but you really are not in a position to throw stones. I don't see this as trivial. I don't think just any one, including a non rigger can perform a modification that could adversely affect the ability of a TSO'd component to meet it's tested parameters with out voiding the TSO. I think this alteration will have to be evaluated and approved by the manufacturers. I think they will have to provide instructions for this approved alteration if they are willing to have it done in the field. Depending on the design I think they may even need to alter their RSL designs to accommodate this puller and may even have to submit those changes along with testing to the MIDO. You have a shiny new toy. We are all interested in your shiny new toy. But I don't think it's appropriate for you to all of a sudden start talking shit about these devices that every one including you have been using successfully for years simply because you now have a new toy of your own. Sorry but I have to call you on this. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

Just as a side note. Some one earlier asked if there had ever been a broken pin and you mention it again now. Yep, saw one. And it was totally unrelated to the capwell pin SB thing. I was at Quincy. It was on an old rig from... South Africa? I think it was called an Intruder? This was years ago but I seem to recall that the reserve tray resembled a Vector 1. The pin snapped in half when I slipped it in the loop and let off on the pull up cord. The pressure of the loop across the grommet snapped the pin cleanly, no sign of bending. I still had a hold of the pull up cord and just pulled the peace's out. Sorry I didn't really take the time to evaluate whether it was locked. I was kind of freaked out and automatically reached for it to see what had happened. It was a clean break but most of the face of the pin was black/corroded except for a crescent moon along one edge. Looks like a crack started some time in the past and slowly grew across the pin till one day I put it in turned the other way and... snap goes the remaining metal. There was no warning and nothing was visible and apparent before. I was going to save it for the wall of shame but the Cypres guys heard about it and conned me out of it. They really wanted that rip cord. They were all excited about it. They traded me a copy of there bird man book for it, and it was a really cool book. Depending on the relative tightness of the last two flaps the grommets may not perfectly a line. In theory The end of the pin could drop down and lock against the edge of the lower grommet. So yes this could happen. I did personally see a pin break in half as I closed a rig once. But that's over almost two decades so it's not exactly a common event. I think I could come up with a long list things far more likely to kill you for you to worry about. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I've been thinking more and more about the design on the Sentinel micro puller. Perhaps you should look at a pusher/puller design modeled after it. A cylinder with a ring on the side and a piston with a ring on the end off to the side in line with the other ring. Both thin so they don't take up too much space. When it fires the two separate from each other. The pin just threads through it. You can now have a completely sealed piston like a cutter. It no longer has to be tacked down in any way so there is no danger of it slipping. It can face in ether direction with out modification as ether a pusher or puller. No issues with housings or replacement rip cords. I'm thinking they had a pretty good design all along. Better then some of the things I was suggesting with plates with grommets on the puller. The answer might be to just update the old micro puller. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I'm not sure I buy that. You are not simply replacing the housing you are replacing it with some thing fundamentally different. A split housing with this puller in the middle of it. And if it involves fundamentally changing the placement of the housing, adding a longer one to reach all the way to be attached to the top flap, that is a fundamental change in design. I would say that that would require an approved alteration. If you further had to alter the rsl, to for instance pull a split housing rather then from between two rings in order to extend the housing all the way to the top flap, that would be a fundamental change that might involve the TSO it self. This puller has the potential with it's seals to increase the pull force. That again relates to issues tested in the TSO affecting airworthiness. AAD instillations, I'm not talking about simply slipping some thing in to a pocket, but real instillations have often been the providence of the manufacturer. There are to many ways to screw it up. So no, I don't buy the idea that you can just swap out a housing and call it trivial. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

2 sec.? Unless I'm reading it wrong I think the sample rate is 1/1000 of a sec. The whole graph covers like 1/100 of a sec. If you hit ctrl + you can kind of zoom in. It looks to me like that 100 lb. spike last 2/1000 of a sec. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I'm wondering if the AAD manufacturers might not be delighted. Now there is a part that they do not make or contract them selves that can be blamed for any failure. if I was them I'd make some vague blanket statement about how they do not guaranty any after market parts, and that the responsibility is on the other players involved but not to forbid it. And then just set back and pray that every one buys them. In fact if I was them I might just have a price hike on cutters, you know inflation and all that. Exchange rate. That's it exchange rate! Now they can still make all the money and ditch all the liability. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

How long is the power stoke/cylinder length? I've got this new wings in my lap looking at how much space there is between the end of the housing and the stiffened top flap of the reserve. There's a big gap over the shoulder where the RSL is. It's soft and compressible. I was just wondering how many designs are like that world wide. To do an in line like this you would almost have to change the housing placement to lock it down to the top flap which would mean at least a moderate redesign of the RSL system as well. What are you thoughts on how the housing should be attached. In the past a lot of the pullers actually required a clamp not just hand tacking to hold them and you're generating even higher forces. Some times the even used a metal plate to reinforce the top flap they were mounted to. All of a sudden installation gets more complicated with housing now mounted on flaps making it harder for them to fold back and all the rest of this that could require enough of a redesign to affect the TSO. What are you thoughts so far on compatibility and over coming this with different systems? Yes, this is a gauntlet. I'm challenging you to provide a drawing, an instruction, even just a description of how it could be made compatible with each system on the market. Take your time. No rush, but you're going to have to figure this out before any one can give you any money. And frankly we're just dying to hear you're answers. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com

I would like to see the force curve with it locked down not moving to see how fast the gas leaks out and the force decreases in the worst case of a hard pull. He has published some graphs but I'm not sure how they were measured. If the pins are moving freely then that might explain the very quick drop off in force as it vents out the end as the piston leaves the puller. Lee Lee lee@velocitysportswear.com www.velocitysportswear.com