IJskonijn

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Posts posted by IJskonijn


  1. I feel it's the right question, wrongly worded. As others have already talked about, it's a tool to gauge the experience of people when jumping together with them, which is vital for a load organiser to ensure a safe and fun jump.

    However, if an FS organiser asks that question to me, the answer is 1300-ish. That won't help him, since only about 100 of those were actual FS jumps. So the better question would be to ask what one's experience is, what they have done before, which positions, etc. Any good load organiser will quickly be able to determine what jump is safe and fun after that. And good load organisers will not look down on anyone for having a particular (typically low) amount of experience, only the shitty assholes will do that.

    Seek out the cool load organisers, avoid the shitty assholes.


  2. Fair enough, but I'm not sure that this route is the correct one to solving the problem of hard openings. Part of the success of the three-ring system (and why it superseded pretty much any other release system ever thought out) is that it is highly reliable. For skydiving equipment, reliability is a very big concern. As already mentioned, a drogue system adds quite a few failure modes which may make it too unreliable to be worth it.

    In practical terms: I see more instances of tandems having drogue issues than I see instances of hard openings.

    The slider already does a very good job of slowing down ram-air canopy openings. It's quite fun (in a slightly morbid way) to take a look at all the ways people tried to slow down ram-air canopy openings prior to the slider. My personal guess would be that an incremental improvement on the slider could very well be better in terms of reliability, with the same effect on reducing hard openings.


  3. On 8/21/2020 at 1:30 PM, sfzombie13 said:

    i was planning on going from my 218 to the 181 sometime when it comes back from the shop.  looks like it may indeed save my life, even if it's not a reserve any longer.

    This part of your post makes me think you might be jumping Ravens (or Super Raven). Although any canopy design is theoretically capable of painfully hard openings, the Ravens have a reputation of also being practically capable for it.

    If you have actual experience with painful openings on one of those canopies, I would suggest you first look into switching to another canopy type that is known for softer openings, before walking the difficult and laborious path of building a drogue system on a sport rig, or the slightly less difficult path of messing around with slider sizes.

    • Like 1

  4. 9 hours ago, 20kN said:

    Lines are responsible for a lot of drag which has a negative effect on how the canopy flies. This is why crossbrassed canopies use HMA 325 and such. The faster the canopy, the more it matters.

    Agree, but for the example of a Sabre2 190, I think that the difference in performance is not noticeable to anyone but an experienced and attentive canopy pilot. And almost certainly it is inconsequential to the type of flying that's typically done with a Sabre2 190.

    And in theory, any canopy can be relined with Dacron lines. Some manufacturers won't offer a replacement dacron lineset for some types of canopy, but if you still insist on dacron lines, any Rigger worth the title can cook one up from a stock roll of dacron. It's a lot more work than the pre-made manufacturer replacement linesets though, so likely a lot more expensive too.

    • Like 1

  5. Regulations will likely be highly variable depending on the country.

    In practical matters, a balloon jump requires a willing balloon pilot and a fair amount of experience by the jumper. If you get scared by the idea of landing off in a field that looks grassy from above, balloon jumps are NOT recommended. Assume you land somewhere that you haven't seen from the ground before, assume the landing field is small, assume there won't be much wind on landing (since balloons only fly in calm conditions).

    If none of that scares you, and if you have enough experience to jump and land confidently in whatever field, I can highly recommend balloon jumps. I've made two of them in my 1300 jump career so far, and both easily rank within my top-10 jumps.


  6. Regarding the bigway record: there's always rumours, but nothing serious has reached my ear. I would image a serious attempt is going to require a multi-year plan with build-up of the bigway skills for the current jumpers. Most of the bigway stuff that I've seen and been involved in during the past couple of years was more recreational-style, having fun and playing around with formations up to 50-ways, but more typically smaller than 36-ways. And there was some stuff going on in the multi-point bigway records and night bigway records last years.


  7. If you have not yet done the basic ground course, there's pretty much nothing you can meaningfully train at home. You need the ground course to know how to do many things properly, then you can practice those at home. If you try stuff before the ground course, it is likely that you'll have to unlearn it later on.

    And yep, it sucks that all the DZs in the Netherlands are closed right now... Nothing to do but wait.


  8. I agree that this should ideally be DZ in-person stuff, but some people are not fortunate enough to have knowledgable people nearby that they can lubricate with a drink for learning this kind of stuff.

    And you got me interested, what kind of monster requires 16 risers?!


  9. Usually, this can be found on the manufacturer website. Different manufacturers have different requirements (sometimes none at all).

    There's a talk on youtube by a British rigger that talks more about this, intermeshed with other stuff regarding inspections etc.

    I have never heard of reserve canopy lifetime being limited or dictated by actual flight time though, only based on amount of activations and/or repacks and/or age.

     

    • Like 2

  10. On ‎2‎/‎4‎/‎2020 at 9:38 AM, Star991 said:

    Well I just have bad history with Sabre 2 and it’s terrible openings along with it’s constant line twist.

    Terrible openings and constant line twists are not necessarily a result of the canopy type. They may also occur when the canopy hits a certain age, and especially when the lines hit a certain age. Most line types (especially microline, which is commonly found on a Sabre2) will exhibit some sort of shrink. This affects the line trim, which in turn affects (usually negatively) the openings of a canopy.

    With smallish canopies (~135 and below) those effects can easily happen after only ~300 jumps on the lineset. Microline will typically still look perfectly fine at that age, so just looking at the wear & tear on the lines isn't enough to determine if the lines are still good.


  11. 3 hours ago, husslr187 said:

    don’t forget about the people screaming “go” behind you even though they don’t know if the spot is good 

    Or even better if they've forgotten that we want to get out 3 km prior due to doing CRW with hardly any uppers. Jackpot is if they climb out right after us. Have fun hiking back! ^_^


  12. On ‎12‎/‎31‎/‎2019 at 2:46 PM, DougH said:

    Those looked awesome until I saw the price. I will absolutely lose my 200 dollar pair of custom ear pro a few weekends into the season.

    That's why I like my €0,15/pair high-end foam earplugs (3M earsoft FX or Moldex Spark Plugs). Plenty good enough protection, and zero worries if I lose one. Sure, there's no super-fancy frequency-dependent attenuation to hear speech more easily, but we aren't holding deep philosophical discussions anyway while skydiving.

    • Like 1

  13. Agreed, metal hardening is a fairly involved process that requires the full skill, test facilities and QA capabilities of a manufacturer. But TiN treatment is not new, and there are plenty of companies that are skilled enough to do it. It might cost a bit more, but I see no major technical reason why a rig manufacturer cannot buy a batch of TiN hardened reserve pins (likely a pin is defined as a part number with associated drawing and material specifications) and test those for use in their reserve ripcords.

    As for the grommet, unless I understand the mechanism wrong, a scratched grommet won't cause as much pull force increase as a scratched pin. The scratches in a pin hook into the loop material, meaning you have to physically either pull them out or pull apart the hooked fibres of the loop material. Scratches in the grommet are also obviously not good, since they can cause wear on the loop and/or grab the loop during the opening sequence and delay (or worse) the opening of the reserve container.


  14. Interesting video & discussion. From a materials point of view, I'm not sure that polishing a scratched reserve pin is a good solution, since the material is soft enough that it was able to get scratched in the first place. Polishing it up removes the scratches, but does not remove the ability to be scratched again.


  15. 14 hours ago, wolfriverjoe said:

    I wouldn't reuse slinks that came with a used canopy, unless they were in absolutely pristine condition. It's too easy to 'cheap out' and say 'well, they're used but they look ok'. 

    That's why you let a rigger look at it and determine if they are still airworthy. It's an absolute waste to throw away slinks because it's not you but someone else who put 50 jumps on them. A rigger will (should) be able to look beyond jump numbers, and determine if the actual state of the slinks merit replacement.


  16. On ‎10‎/‎16‎/‎2019 at 8:45 PM, RiggerLee said:

    I hope you got that fabric for free. It totally saturated my screen and caused strange artifacts around the edges. Hideous.

     

    Lee

    That's why he was wearing sunglasses! B|


  17. If the canopy doesn't already have an attachment point, then it will need some work by a master rigger to create one, especially for jumping it repeatedly.

    As Lee already said, reserves have some different materials used for fabric, but also for the lines. Typically, they are uncoated (to reduce risk of sticking/tension knots I think), which means they are much more susceptible to damage than normally coated lines. Keep an eye on it, and don't expect to get 500 jumps out of it.


  18. Based on their manuals, neither the Solo nor the Solo II can be adjusted in their volume. The Optima and Optima II can be adjusted, but the lowest volume on Optima II is 112dB, still painfully loud. Wikipedia helpfully states this is above a non-electric chainsaw at 1m distance.

    Concern regarding hearing loss is valid, but in my opinion better solved by use of earplugs rather than by adjustment of an audible. Ear plugs have the added advantage of protecting against engine noise and freefall wind noise as well as against super-loud audible noise. Think of it this way: earplugs generally lower ALL volumes. If you can hear your audible in freefall, it is loud enough to rise over the rest of the noise. By lowering ALL volumes, you don't change the difference in audible volume vs other noise volume. So you'll still hear your audible perfectly fine.

    Anecdotically, I use my Optima II mostly for canopy alarms, and typically in my front pocket due to a halfshell helmet (#CRWdog). Those rare cases where I have my audible inside my video helmet and I forgot my earplugs, even the canopy alarms are physically painful to hear. Earplugs are the way to go, and even very high quality foam earplugs will only set you back €30 for 200 pairs, just €0,15 per jump if you grab fresh ones every jump!


  19. There is no specific jump number for this type of stuff. My advice: discuss it with the instructors at your home DZ, and find a demo jumper that has experience jumping with extra stuff. Any jump-specific advice (like higher pull altitude, things to keep in mind, etc) are highly dependent on details like your actual experience, the exact way you want to do this, how you're going to make and hold the banner, etc...

    Generic things to think about and discuss with said instructors and experienced demo jumpers would be: How to hold it in freefall while maintaining stability (restricted use of arms)? How to handle it during deployment? What happens if you do lose it? How do you exit properly with it (also depends on airplane type)? And probably a couple other things I'm forgetting here.

    • Like 1

  20. 11 hours ago, PlaneFun said:

    Thanks everybody for the great suggenstions! I didn't even consider checking the grommet or pin for burs. I'll do that, maybe shorten the loop, and show it to the rigger if it continues.

    Take it to your rigger first chance you have, rather than "if it continues". That level of loop wear is abnormal, and a rigger is the most qualified person to diagnose the cause and get you sorted with a good solution.

    Worst case outcome if you go to a rigger: Some grommets and/or your closing pin needs to be repaired/replaced. Maybe a day's work and similar costs.

    Worst case outcome if you don't go: your loop breaks while you're doing a floater exit in the door, and your canopy wraps itself over the tail of the plane. That rips it off, killing you and everyone else still in the plane.