sundevil777

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Posts posted by sundevil777


  1. 8 hours ago, Maddingo said:

    It's an elliptic canopy so it is quite normal. Even my Volt turns a lot and it's a semi, also why are you on such big elliptic canopy? How much jumps do you have?

    I don’t understand your comment about it being so big.


  2. 2 hours ago, meat.missile said:

    Try commenting in good faith. 

     

     The pro tech would be better than the G3, but I’m not sure how it compares to the G4. 

    Are you trying to be a troll? 


  3. What is so magical about that standard? I am certain that a tougher standard could be written, that would provide more protection that would help in some scenarios, and that would require a heavier, bulkier helmet to comply. The standard is a compromise, but you don’t seem to see it that way. I have no doubt that it performs better than the G3, but to assert that not meeting the standard makes the protection provided insignificant is not correct. This is not how engineers should analyze problems. I was sure we could have an interesting conversation about the new helmet, but this is really tiresome. 


  4. 2 minutes ago, meat.missile said:

    When you have a fundamental understanding of a subject you don't always need to see the numbers to know the general outcome. 

     

    Anyway, found the reference to the standard from chuting star.

    "The XPS 72-600 is a Skydiving and Windtunnel Helmet standard used for the G4. The impact testing is the same as the EN966 standard for drop height and conditioning prior to impact (5.47 m/s at roughly 1.6 meters). The impact must be less that 250G. The XPS standard also requires a SNAG test, while the EN966 does not. The XPS requires the chinstrap to be on the exterior of the shell so that a line cannot pass up the inside of the helmet, while the EN966 does not. The EN966 is a Hanggliding helmet standard and also has a penetration test, while the XPS does not require a penetration test. However, Cookie has tested the G4 helmet for penetration according to EN966 and it passes with "great results," says Cookie."

    Knowing the general outcome is very different than so confidently asserting the G3 provides insignificant protection as you have defined. You are not the only one with an engineering/technical background. The info you provided does nothing to clarify how much better the G4 is. It would have been very easy for Cookie to let us know how much improved their new helmet is, but they did not. Quoting the new standard's test setup and pass criteria gives us nothing with which to compare the G3. Quoting what the old DOT motorcycle helmet standard was does nothing to inform us of how well it compared to typical helmets that were common before the standard.

    Most engineers I think would not make such assertions without evidence. Why are you so determined to defend your position. I really don't understand. Can't this be discussed without insults?

     


  5. 11 minutes ago, meat.missile said:

    Dumb, just dumb. 

     

    Standards are a pain. To add some more info, XP S 72-600 is EN966 + some stuff relating to snag resistance. But as far as impact goes, it is the same. (I can't find my source on that, but I'll keep looking for it.)

    You assert "insignificance" without any data to compare the performance. I have no doubt the G4 performs better than the G3. Without data to back it up, your assertion that the G3 protection is insignificant as you define it, is unworthy of an engineer.


  6. 49 minutes ago, skybytch said:

    Boom. May also be an issue with packing if it is happening on two different canopies. 

    Husband and I both jump Spectres with Dacron.  He's put over 1000 on one, I've got a couple hundred.  No hard openings, ever.  

    Quite right!

    Dacron just works well, and not just because it is able to absorb some of the shock:

    https://www.dropzone.com/forums/topic/266092-dacron-lines-are-good-not-just-because-they-absorb-more-shock/?do=findComment&comment=4861211

     


  7. I always withdraw the pull up cord when there is no tension on the closing loop. I put my thumb on the loop during the final pull through the final grommet, when it is pulled through farther than needed as the pin is inserted, and withdraw the pull up cord with virtually no resistance force at all. This has resulted in a closing loop that still looks absolutely new after about 90 jumps. I think that if you can't pull the closing loop through farther than needed to accomplish what I've described, then the loop is too tight. Others may think it means my loop is too loose, but I don't think so. So often I see people pulling their pull up cord very fast through a very tight loop, and even if they situate it under the pin before withdrawal, I think the potential for needless wear is great.

    The modern, wide pull up cords with heat-sealed edges at the ends I think are particularly harsh on closing loops. The old-school gutted 550 cord were much gentler I think.


  8. 37 minutes ago, evh said:

    All kidding aside, I actually think its a good development that manufacturers are testing the performance of their products. Its just that I cant stand the claim of "improvement" without even testing the old situation, this is nothing but empty marketing hype.

     

     

    Quite right.

    One would think that if the G4 was such an improvement, Cookie would be advertising about it, with graphs and videos from the tests and such. I would expect that skydivers being the tech wonks that we are, we would eat it up. Many more people would be replacing their G3 if there were solid data to back up the improvement. We are left to wonder if the numbers actually are impressive.  The standard to which the G4 complies might result in 50% less g loading, or 5% or who knows what? That standard may be no more ambitious than the old DOT motorcycle helmet, which was not at all ambitious.

     


  9. Back when dinosaurs roamed the Earth, motorcycle helmets had their first (I believe) impact standard in the US issued by the DOT.  Many years later, a private organization issued the Snell standard because it was recognized that helmets could, and should be much better. The Snell standard was much tougher to meet.

    At some time in the future, we may conclude that the standard to which the G4 complies is inadequate. It would be wrong to say that standard provides insignificant protection just because a better standard might exist.

    I only wanted to know how insignificant a G3 is compared to the G4. Is that somewhere in the deluge of documents?


  10. 1 hour ago, meat.missile said:

    This is a ridiculous argument. You are spreading bad, potentially life threatening information.

    If you take speculating to mean, my education in mechanical engineering and studies on how helmet design and padding effect the amount of energy transferred to the brain, then yeah, I'm speculating. Or maybe it is my educated, informed, and professional opinion.

    But sure, don't listen to me, leave the prevention of brain damage up to some thin foam. 

     

    I also have a mech eng degree. I haven’t spread any bad, life threatening info. Please take it easy, I didn’t think curiosity would evoke such a reaction. Someone might actually know the answer to how well the old vs new helmet compares. It definitely will be better than nothing. 


  11. There is no misunderstanding of how helmets work.

    The point I would make is that without data, we don't know if the liner for a G3 is 0.1% or 1% or 10% as effective as the shock absorbing material used in a G4.


  12. Without test data to compare the performance of a G3 vs G4 vs no helmet at all, we are speculating on how negligible the impact protection of a G3 or any other helmet is. Maybe we already have the data to make that comparison?


  13. I’m a 24.5 head. The Kiss XXL fits well and I bought one. The XXL G3 won’t go on. My old Z1 was bigger than either. 

    Big noggins are tricky for fitting helmets.


  14. Related to the question is which canopy was the smallest. Please let us not consider canopies used for hang gliders and such.

    I would expect the KXX to be in the running, correct? For the custom design used for the around the world flight, couldn’t they have done better than a Phantom? 

    Edit: it was said that only a tricon would fit, do we all agree that it is the smallest?

     


  15. I remember a “Viking” from way back. Welcome back.

    I suggest not asking a DZ what will be required to jump again until you are actually there on the day you’ll jump, and bring video/photographic evidence of your prior skills. Some might say it doesn’t matter, the only way to get back means a very expensive way, but I think the person that actually makes the call is much more likely to be less strict in person. Be humble but confident in your abilities and they might just require you do a normal jump with an instructor, not be treated like someone that has forgotten how to fall off a horse. That was my experience when coming back.

     


  16. 2 hours ago, sundevil777 said:

    I had forgotten about that version. 

    It seems like it would be prone to activating before leaving the aircraft, as there can be significant time after the pin is pulled before exiting.

    Never mind, the specifications say there is an activation delay of 5 to 7 seconds.


  17. 2 minutes ago, RiggerLee said:

    There is a Air Crew Cypres. You find it in emergency rigs, single canopy rigs for pilots and flight crew, mostly military or contractors. 

     

    http://www.ssk.us/EAC_20031202.pdf

     

    Lee

    I had forgotten about that version. 

    It seems like it would be prone to activating before leaving the aircraft, as there can be significant time after the pin is pulled before exiting.


  18. There was another thread a little while back, should be searchable. 

    My guess is that it has less value as experience increases.

    I also psycho pack every time because it is so easy.


  19. 5 hours ago, billvon said:

    Holy cow, a CONVENTIONAL gear aircraft sold to a regional airline?  That will see some interesting changes in pilot training . . .

    Also quite unusual for a fuselage mounted pusher on a tail dragger.

    the article is a bit loose with mechanical details, such as claiming about 10 moving parts for a 6 cylinder internal combustion engine.


  20. Excellent, I was equating screaming with the last alarm, I should have known better. It is great to see more choices and innovations 


  21. 21 hours ago, spdFlyer said:

    I have one and it works great. I like the fact I can choose a time and length. I keep the most common break off altitudes set and have it set to scream at me at 3500. 

    I think that the last alarm, which I presume is what you meant, should be used to remind you that it is time to stop messing with a malfunction, not that it is time to deploy your main.