dorbie

In helmet design padding thickness is critical. When you get so excited over a material that you dispute this it fosters ignorance. For an equivalent thickness it may be better than other options, I've said as much, but it's totally unproven, I've also said it's an improvement on Cookie's cloth pads, it may not be as good as the best foam option in a helmet. That data sheet does not describe a CE certification for the material. Read it again. "3DO makes a range of parts certified to EN1621-1" Perhaps you weren't aware, EN1621-1 is a motorcycle protective clothing standard, and I specifically mentioned several times that the only place I'd found 3DO CE certified is in specific garments. It is irrelevant w.r.t. helmets for all the reasons I've already described. So you've actually confirmed everything I said. The most intriguing part of that sheet is the graph of impact force vs. thickness it's superficially impressive, but testing highly deformable foam without a hard shell would be misleading for helmet liners but that's exactly how you'd want to compare 3DO for best results. The numbers suggest that's what's been done but there's no info beyond the bar chart, it's a marketing graph. Impressive performance for one impact application (and it IS impressive where deformability & flexibility is needed) does not translate to impressive performance for all applications. This stuff could make a really impressive flexible frap hat for tandem passengers and other jumpers. For a liner the case has not been made.

Bribery always works with shills :-) This thread was disappointing, popcorn wasn't even cold before it all died down. Now you're giving shit away

Thickness of the padding is absolutely critical because it sets the absolute lower limit of acceleration forces in any impact, it's basic physics, and of course it is limited by the space between the head and the helmet, as I mentioned. Space between the shell and the skull is not a random number, it is something designed by the manufacturer. It is specific to the helmet design and is why you cannot rate a material for head protection, only a helmet design. If you're saying thickness is not a factor because space is the factor and space determines thickness then you have have that idiotic debate with yourself. So you simply cannot cite the material CE rating or even the standard you think the material meets, you've just heard it from somewhere: Hype. Again, helmet CE ratings are awarded to designs. You can no more say 3DO is rated for head protection than you can say cardboard is, it's a silly claim. Your argument boils down to "believe the marketing". NO, what skydiving helmet can I purchase incorporating 3DO that has passed any CE rating for head protection and cite the specific CE test. The ones I could find were for specific garment designs. Right now my working assumption for this material is; no better than good foam padding when inside a hard shell, but probably a lot better than the pads I have in my current Cookie helmet. Hype will not change that, numbers might. Still probably the ideal choice for a modern frap style tandem hat.

No because there is no way to compare what isn't measured/rated. The D3O material has passed the CE certification process and therefore transmits a certain amount of energy (or less) to the wearer. Other than the Protek, no other skydiving helmet has the CE certification. How can I then compare the performance of these helmets without getting a whole bunch of empirical test data. If that's what you're looking for, you're barking up the wrong tree. It's an important question though because we should all wonder about what are helmets will do for us when we really need them. What do you mean by "in a hardshell"? There are a bunch of different CE ratings. http://www.parachuteshop.com/protec_certified_to_cpsc_1203_u.htm http://www.climbing.com/print/equipment/helmetcertif/ http://www.roadrunner.travel/article-5915.php The amount of force required to cause damage to a human is known (I believe it's 4kN) so the CE rating isn't the be all, end all. It's a positive step for skydiving helmets to be incorporating measurable protection. That first quote is not from me the second one is. Materials don't have CE impact ratings, individual designs do. In any helmet design the thickness of the padding would be critical to attaining a rating. The CE ratings I could find for items incorporating 3DO were flexible garments with features like 3DO in the knees and other critical areas. Something the material seems perfect for, but it has nothing to do with helmet designs with a liner inside a shell. Even if a helmet with 3DO had an impact rating it would be irrelevant when discussing a different helmet design, especially one with a thinner liner. By "in a hard shell" I mean that you have an outer helmet shell and a 3DO lining. This means that you do not need the impressive 3DO property of becoming rigid on impact and spreading point loads over space and time while being flexible when not under an impact load. The hard shell is already rigid, you primarily want a material that crushes offering an optimized level of resistance to that crushing over time (a matter of many scenarios, variables, choices and tradeoffs) to spread impact forces over time thereby reducing them. You also want as much space between your skull and teh shell within which that material can do it's job. It may be that 3DO is good at this, but it may also may be that to prevent loss of consciousness going rigid at the moment of impact is not what you want from an impact absorbing liner. Perhaps it's rigidity IS optimal for this purpose and minimizes impact forces over a wider range of accelerations. We just don't know. It's simply hype. Sticking a thin layer of heavily promoted wonder-material in there does not resolve the space issue and really says nothing about its ability vs. good foam of equivalent thickness. Now a soft frap-style hat made out of 3DO would have some significant justification (like the snowboarder hats with 3DO now). Something that you could put on a tandem passenger that would protect the TM's chin as well as the student's head. CE rating for skydiving helmets could be a big step forward, I agree (provided it's not mandatory and customers get to decide). What's a huge step backwards is vaguely attributing the benefits of a CE impact rating to a range of helmets that have no such rating because they use a thin layer of some hyped material used in other designs in other markets that have properly earned their CE impact rating.

That CE rating (specific to particular garment designs) is a rating for clothing. I'm was referring to a real demo promotional video where it pretty much was whacking a lump of stuff with a hammer at a trade show, looked and acted very much like silly putty to me. So it's not ME that made the demo up, but like you I take issue with it. Again it seems clear that 3DO's strength is in it's ability to become rigid on impact when you need protection and FLEXIBILITY. That's not necessarily the same role you want for crushable liner inside a hard shell. However, I own a couple of skydiving helmets and 3DO is probably better than the crappy liners in either of them. When you stick this wonder material in a hardshell I think you risk a lot of baseless marketing hype, until I see some numbers showing otherwise comparing a hard shell with 3DO vs. equivalent thickness of conventional liners. Anyway good on them for taking the liner seriously instead just having cloth comfort pads.

Hey, any way to make that attachment Mac friendly? The file extension is *.kmz . I have NO idea what that is. Could you possibly post it as a PDF file? I'm sure it's a great layout of your home DZ and I wouldn't want to miss it. Danke schon I worked for Keyhole and helped write Google Earth. KML (Keyhole Markup Language) is an ASCII text based XML based file. Platform compatability should not an issue. KMZ is a compressed KML file (zipped), platform should not be an issue. The compressed files are just after my time there but the engineers I know there would not have made it anything other than cross platform, they're just not that dumb. If you are seeing an issue with KMZ on a mac it is probably that it is not associated correctly, endianness should not be a problem for either format. It may be case sensitivity with the extension but I'm not a mac guy so I wouldn't know if it is sensitive to this where a PC is not. You could also try unzipping the KMZ and making sure the result has a .kml extension. Use gzip or equivalent mac tool. You can then take a look at the ASCII in a text editor or load it into Google Earth. P.S. you also have a byte stream ASCII file going into a byte stream compressor, zip, there is no place for platform compatability to creep in, although when you uncompress it you'll need a compatible zip, (most should work but it's worth knowing when getting your hands dirty). You should also ensure you have the latest Google Earth version.

I was pretty keen on getting a gas until I noticed that the 3d0 was only on the top of the helmet. It seems like that offers a limited amount of additional protection; not quite enough to justify switching just yet. That's sad if true, but then the 3DO seems unproven anyway. You want something that packs down during near linearly during the course of deceleration. That is impossible for all velocities so anything is a compromise. Something with dynamic response may be better than alternatives but it depends on the details. Simply making the claim while whacking silly putty with a hammer does not make the case for it's utility inside a hard shell, (the compelling case for 3DO seems to be where you don't have a hard shell but want flexibility). And NOTHING in skydiving is anywhere close to the benefit of a motorcycle helmet where (most designs)pack down on first impact. That is utter bullshit. It is worth pointing out that there are two competing requirements which demand different optimizations, one is a design that uses the crush space to maintain consciousness for a range of impacts and the other is one that uses the crush space to maximize survivability. Since there are impacts that might render you unconscious in skydiving that would not kill you directly it can legitimately be said that there are competing design criteria since staying conscious while skydiving is an issue of survivability. More space between your skull and the hard shell is always good and skydiving helmets compromise too much on this, and then worse, many have a sorry excuse for a liner in that space.

+1

You willingness to forgive of this type of behavior has brought it into question. Sparky YEA, you tell him! That'll teach him to disagree with a baying mob.

Yes, agreed to all of this. To point 2, yes, and canopy pilots need to guard against the difference flying an equivalent ground track might have in different winds, especially in the pattern. They can for example be tricked into a dive although they perceive the flight maneuver is not that radical. There's a double whammy here if matching a ground track; making a 90 turn from downwind onto a base leg matching a ground track reference must become significantly more than 90 to match that ground track AND is more likely to be executed as sharp turn inducing a dive due if it is not anticipated as an extended eliptical ground track turn. So it is necessary to take the time and distance to execute the turn safely. It may have a bearing on the fatality that sparked this discussion.

Toggle input is an external force. The wing does not have a static shape. Fly directly into a 20mph wind. Stall your canopy, then release the brakes. Results may vary. Steering lines can be used to change speed and the shape of the canopy. The wind will have a different effect on a canopy when its shape has changed. None of this affects anything that has been said. It doesn't matter where the force comes from. It is the SAME flying at any speed in any configuration whether in wind or not. The only thing that changes is ground speed. Consider the fishbowl analogy. Imagine you're flying your canopy in a massive fishbowl full of air and making turns. Now put your massive fishbowl on the back of a truck and drive it at a steady 60 mph and fly your canopy in it If if the fishbowl is opaque and you can't see the outside world, you would not be able to tell the difference between moving or not the turns you make would look and feel the same. Now make the fishbowl transparent and you're flying in 60 MPH wind, upwind & downwind turns are the same in either frame of reference. If you don't understand this then you have no business trying to argue the point, you need to take remedial physics 101. Stall your canopy and release the brakes and you will fall with the moving air such that your horizontal airspeed will tend to zero as your vertical speed increases. Drop a lead weight and it will fall with the moving air if given long enough to stabilize, it will not fall vertically in wind, it will move until it's horizontal airspeed is near zero through friction. This is why you calculate wind drift during freefall due to 'uppers'.

I love the fishbowl analogy, brilliant, I had not heard it before. And they're categorically wrong. There is no known physical process known to do this to any perceptible degree. It is a psychological issue. Edit to add, unless they turn differently or ALSO say that when turning from a downwind to upwind with the same control input they also experience the same loss of lift.

High winds have no effect on your canopy vs. no wind once you're flying in them, except that they may tend to be more turbulent, but for the purposes of this discussion that's moot. The only thing that changes in high laminar wind vs. no wind is the ground speed, but that's a big change and can cause humans to make mistakes about their rate of turn with varying ground speed, e.g. turning faster when heading downwind causing a sudden loss of altitude due to the canopy diving (or even inducing a stall in some aircraft). This is directly related to Newton's first law of motion, read it and take it to heart: It says "uniform motion", not stationary or moving, there is no difference between the two states. Your canopy in equivalent flight has the same airspeed in all laminar air, windy or not. The aerodynamic & gravitational forces applied have the same effect. Momentum is the same in the pilot's frame of reference. This is not up for debate if you disagree you're wrong and may kill yourself if you think you need to or can turn differently downwind vs. upwind. And don't feel bad about not knowing this, it's an infamous and insipid debate in aerosports. It will not go away with this thread. Believe Newton's first.

Or after landing the person steps through some lines. I've packed myself a step through twice and landed both of them. But then were simple flip step throughs, not crazy ones like in this vid. Ahh, I always thought a line check would catch that. No question it could cause it if you don't trace your line groups up from the risers.

As others have said, it's a stepthrough. After bagging the closed bag has been passed through a set of lines. The kink in cable is from the RSL, I've heard this called a pig tail.

You're right. Of course it was still pretty f*cking stupid. So is jumping out of an airplane. Whatever. Get a profile if you want to be taken seriously. Whatever skycop. Learn to admit when you're wrong if you want to be taken seriously.

Yes, AFF and rental gear jumps bruised the heck out of my thighs it's normal. Since I got my own rig I've never been bruised.

You're right. Of course it was still pretty f*cking stupid. So is jumping out of an airplane.

I hope people are paying attention so they don't repeat the right royal fuckup you clowns in NZ have made of the sport there.

The chopped main canopy is usually there and easier to spot. And there will be no pilot chute killed or otherwise trailing behind the canopy. Reserves are also usually a single color, white or bright.

You could also take him for a tandem paraglider flight here in the USA.

Nah it was so much better when there was a chance it was real. I still think it might be and I don't want anyone dragged over the coals for it. Fat git was fair game. I want it to be real so bad I'm just gonna ignore the "BINGO" and nonsense about knowing terror. You have to laugh when people baying online use the old "professionalism" angle.

Do you mean shveddy's Vectoridea4?

I vote for the hideous all color design of shveddy that he posted as Vectoridea4.jpg I call on all contributors to to support this effort to get this rig built and teach bigway a lesson in executive decision making . Who else will +1 for shveddy's Vectoridea4? And we need photos when it's built!

When they don't have a canopy to look at it probably increases the chances they'll look at the rip cord.