Deimian

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Everything posted by Deimian

  1. It is also used in most paragliders, AFAIK. But they don't call them cross-braces, they call them diagonal ribs. These are interesting articles: https://www.advance.ch/nc/en/home/news-pages/tech-series/tech-report-sliced-diagonals/ https://paraglidingmechanics.wordpress.com/2016/01/21/structural-design-of-a-modern-paraglider/ It is my understanding that paragliding wings are much more advanced than skydiving wings. But they have a totally different set of constraints, and a bigger market, so the difference in development is justified IMO. Here some examples
  2. Deimian

    Hurricane to Cool openings

    Some (elliptical) canopies are quite "searchy" on openings. They will shake you from side to side, no matter how you pack them. I am not sure there is a lot to do about it. Katanas and Velos are prime examples. I have no experience with Hurricane's, but I am not surprised. If you want to get rid of that I would suggest to change canopies to something less elliptical, or a more modern design with the openings a bit more under control. I can recommend an X-Fire for that. I think that the Echo from FW and the Crossfire 3 are also canopies with great on-heading openings.
  3. Deimian

    UPS left rig in truck for 3 days

    The same happened to SunPath https://www.sunpath.com/wp-content/uploads/SPSB004.pdf But those were exceptions more than 15 years ago
  4. Deimian

    Russian paratroopers

    Very interesting video! Jumping in front of a turbofan engine gives me the shivers. It seems like the engine is off during the jumps, but still.
  5. Deimian

    Packing innovations

    Appropriately sized rubber bands do not hold the whole line group tight if they are not single stowed and any force pulls a bit on them. The lines on the gap between the rubber band and the bag will be loose. Hence, single stowing short rubber bands do not eliminate the need for double stowing. I single stowed many jumps. I agree that in many canopy/line/bag combinations a tight rubber band will be enough for most of the time. But the mechanics are there and support that double stowing is the best way to ensure that the whole group will release at once. Whether that is important or not depends entirely on the situation of each jump, but for sure it won't hurt.
  6. Deimian

    Packing innovations

    Except that single handed vs 2 handed reserve procedures both have pros and cons, and therefore they could be discussed or be a matter of preference. Double stowing doesn't have any in-air "con". Sure, replacing rubber bands more often is a pain in the ass, but that is far from "with single handed EP you can die this way, and with double handed EP you can die this other way".
  7. That'd mean you can be on sit as fast as the 100th fastest head-down skydiver ever recorded...... http://www.speed-skydiving.com/index.php/rankings/eternal-ranking-barometric. If 420 km/h was your normal speed your skydives would take around 30-35 seconds, including time to accelerate and decelerate. I bet they are a bit longer. I do believe though that you can see that on your app or even protracks, but you are not accounting for burble effects and sudden changes in pressure. For instance, when switching from forward flying (wind on the back while sitflying) to backward flying (wind on the chest). In these cases the sensor will register very rapid changes in pressure, and the formula will result in a calculated vertical speed that is far far away from the reality.
  8. Deimian

    Full-face helmets

    If I shave with a razor blade and jump or fly in the tunnel, the helmet and suit neck rub against my neck and I get a bit of acne for a couple of days. The area is also itchy. Are you shaving with a razor blade before jumping? Maybe try something that lets the hair a bit longer? I am using for the last couple of years Philips OneBlade, and even though my shave doesn't look as neat as with a razor blade, my skin is much better and I have no issues with the neck of the suit or anything like that.
  9. Deimian

    HELP!!! Jumping in Austria.

    Maybe you could get a FAI license in the US? That should make it easier to convince them. In any case, it doesn't tell you that you have to do a course, just that you have to pass a (written) exam. Maybe the DZ would like also to make an AFF jump with you.
  10. If deflection of the airflow off the bottom skin is the cause, then a domed slider would inflate in the opposite direction, and the deflection would push it down the lines harder, no?
  11. Deimian

    USPA Board Meeting

    I think that's the point of the BSR. To make it conclusive they have to make sure that the vast majority of people reports incidents. My understanding is that BSRs are the only tool USPA has to pressure members, ST&As, DZOs, etc to report. Some might choose to don't do it out of hypothetical "what if"s, and operate on the "margins". Most would probably do it because it is in their best interest. You have repeatedly asked why a BSR, since it is too aggressive and unnecessary in your view. What would be the alternative to ensure the highest number of reports possible, without making it a BSR? I don't see it, but I am not based in the US. Besides that, what some people are telling you, is that you are coming across as a whinny person accusing USPA and the board of being evil-doers and self interested. The reason for that is that you complain without offering an alternative, and you are repeating yourself without listening. Focus on proposing alternatives and you'd be seen as someone constructive, and how people perceive you will change. Keep focusing on complaining and no one will listen to you. Just my 2 cents.
  12. Deimian

    Canopy transition for downsizing

    IMO the same applies to back riser landings. Stalling the canopy on rears is quite easy, and novice jumpers just don't have the finesse to know when this is going to happen. Even in flight 1 courses rear riser landings are out of the question until 201 or 202 (don't quite remember). I think that list makes a lot of sense for the intermediate crowd, but a couple of bullet points should be adjusted for novice jumpers (again, just IMO)
  13. SIFE and SWS use both collins lanyards with pin based MARDS.
  14. Deimian

    New AAD made in USA

    I actually think that so much flexibility in an AAD is a horrible idea. If that was possible you'll have all sorts of misconfigured AADs and a spike in misfires. People don't know how to turn off their VISOs, why should we play with AADs settings that freely and dangerously? Multimode AADs and user selectable altitude are already a possibility. And despite that simplicity there were misfires.
  15. Each of those rigs can be more than $10K. They stole multiple. This is a DZ, not a private apartment or house. What has your private renters insurance to do with this situation? What about the lack of income because they can't put out as many tandems without those rigs? How is your remark of any relevance here? Who are you to tell someone else that their worries are not justified? Gowlerk is right. I don't know you, but you are certainly coming out in these forums as someone that should listen more and talk way less.
  16. As mentioned before: that really depends on the canopy type and size.
  17. Resist wear and UV light damage. It is far less likely to break when worn. Line choice is full of compromises. Some, especially larger lightly loaded canopies are less affected by being out of trim. What he said. Spectra is the strongest and longer lasting material. Big canopies fly just fine when out of trim. That's why you don't see spectra in smaller canopies, proper trim is key. In the middle range it is all a matter of preference. It is a trade off between durability and dimensional stability. If you are ok flying a wing that is not in its optimal shape, but you appreciate the peace of mind of the higher endurance of spectra, you use spectra. If you are diligent with maintenance and take care of your lines, and want your canopy to fly the the best it can, then you'd use HMA or Vectran.
  18. Deimian

    Collapsed Slider Still Noisy?

    You'd still have to pull the rings down, at least on rears. At least that's what I see (I don't jump with an RDS) Yes, you pull all of the rings down with a removable slider. What's the problem with that? No problem from my POV, but the OP asked how to make the slider quieter without pulling it down. An RDS was suggested, but if you still have to pull the rings down then the OP hasn't found a solution yet. I don't know why he doesn't want to pull it down though...... Nothing wrong with it IMO (quite the opposite)
  19. Deimian

    Collapsed Slider Still Noisy?

    You'd still have to pull the rings down, at least on rears. At least that's what I see (I don't jump with an RDS)
  20. Deimian

    Shortening laterals

    I didn't expect that. Why would they need to do it? What you describe sounds like replacing the laterals, instead of shortening them. I guess it depends on where are the ends of the webbing (at the MLW junction or hidden in the back)?
  21. Deimian

    Shortening laterals

    Well, for that particular problem, a very good fix. I'd guess that it takes a fair amount of work to remove the stitching, unstuck the glued bits, cut the ends of the laterals, sandwich and glue the laterals and MLW together again, and re-stitch it. But if the glue can be removed easily and without damaging the webbing (I guess that is not really a concern since this is offered by the manufacturer) I don't see how that could be a problem.
  22. Deimian

    Built in turns

    This is weird. I bought an X-Fire second hand. Turns out it was missing the "minirib" of the right stabilizer. The sent me a new one right away, no questions asked.
  23. I couldn't disagree more with your last statement. Particularly when considering the first sentence. You are basically saying that a torn canopy is not a reason to cut away. What the hell? I understand that with a Zero loaded at 0.77 a rip on a cell is survivable. Now, imagine a novice jumper with a regular canopy reading this, being afraid of cutting away, and having a torn canopy. Does it sound like reasonable advice to you? I can't believe an instructor wrote that. BTW: Who doesn't open with their belly to earth?
  24. Deimian

    Stuffing into centre cells... wtf?

    I've seen plenty of Sabres in Europe. Every weekend I see 3 or 4. But obviously they are not that popular anymore. And yes, you can use Sabre 2 for everything. Not that I would recommended them for wingsuiting for instance (which is a specific kind of jump....), but it is not downright stupid. I flew Sabre 2s in different sizes for a few years, and the openings are far from being tricky. For sure they aren't on heading, but I don't recall having twists or wild openings ever on a Sabre 2.
  25. Deimian

    LB Ares II digital altimeter

    Trade in? Is there any short of trade in program somewhere?