IJskonijn

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Everything posted by IJskonijn

  1. A two-out can also realistically occur at normal pull time, if the reserve pin is almost out of the loop and the shock of the main opening takes care of the last little bit. I'll agree that will be a pincheck fail, but two-outs don't happen because everything went perfectly fine. Still, I agree that a two-out downplane burns through your altitude like crazy, so there's not much time to make decisions.
  2. Honestly, I fail to wrap my head around even the concept of a
  3. It's certainly possible to make a contraption that allows you to pull down a huge tail. Pulleys are well known for being a force multiplier (at the cost of having to traverse greater length). However, basic physics still dictates that this is very unlikely to work. In order to stay aloft, you need to replenish the energy in your system (pilot + wing) that is lost. Energy is lost due to drag, and for typical skydivers this energy is taken out of the amount of potential energy available. That's why we generally go down, not up. Making such a thing viable means getting the energy loss below 400 watts, since that's about the limit of what a trained athlete can generate (for normal adults it is about 50 to 150 watts, according to Wikipedia). And this is still not talking at all about how to get that energy from your body into the pilot+wing system. To get to 400 watts energy loss, assuming the entire system weighs 100kg, you need a descend rate at or below 0.4 m/s. (E = m*g*h for potential energy) Let's look at paragliding wings, since they are among the most efficient non-fixed wings that I know of. The Wikipedia article on paragliding quotes glide ratios of 9.3 to 13 in extreme cases, and speeds from 20 km/h to 75km/h. Lets assume both the maximum glide ratio (13) and the minimum speed (20 km/h), since that will minimize the energy requirements. 20 km/h is 5.56 m/s, which at a glide ratio of 13 means 0.43 m/s downward speed. Sooo close, but not enough. And oops, we made some very far-fetched assumptions (100% efficiency in getting the energy you generate into the wing, a top athlete that doesn't get tired, a highly efficient wing flying at very slow speed to minimize energy loss from drag). To succeed, you will need to design a wing that is significantly more efficient than a paragliding wing. If you can do that, I'm sure there are quite a few paragliding (and parachuting) manufacturers that would be happy to hire you onto their design teams. However, as it stands, I see a brighter future for you as an animator.
  4. And I still unfortunately see quite a few CRWdogs with tethers on their hook knives... Yes, losing the hook knife is a potential issue. Been there, done that (I still like to think there's an alligator in Florida somewhere with a headache because of my hook knife). The better solution is to carry multiple hook knives, so you have spares. And while you're at it, carry them at different positions. I have two in a pouch on my chest-strap, accessible from both sides, one on my right leg (sewn onto my jumpsuit) and one under the left mudflap. And when in doubt, remember the CRW-dog reason for carrying 10 hook knives. ^_^
  5. Easy, there are other threads on this forum where you can go yell at people for wanting to jump with a camera. Or go to an actual dropzone. There's nothing wrong with taking future growth potential into account when searching for a helmet. I don't think helmets are purely a fashion statement, although looking at some people (and the prices of helmets) that may seem to be the case. In the old days (at least, as the stories are told by people older and wiser than I am), helmets where a student thing, to be ditched as soon as was allowed. Luckily, nowadays they are much more common, in part due to mandatory helmet use for certain disciplines. Here in the Netherlands, a hard helmet is required for freefly jumps. And even when helmets are just a plastic shell with some fabric liner, I agree that in any given situation having A helmet is much better than having NO helmet. On the other hand, having no helmet may make a person more careful, reducing their chance of getting into such a situation in the first place, so the net worth may not be beneficial. The easiest solution would be to require helmets that conform to some safety standard. An easy pick would be EN966, which is the EU safety standard for paragliding, hang gliding and ultralight helmets. In the meantime, I'm going to stick with my skate helmet for CRW, and I'll probably pick up a PG helmet when I start getting into canopy piloting. I don't do much freefall, so I have no real need for a freefall-proof helmet.
  6. The economics of developing a crash-safe (defined by meeting applicable standards) helmets specifically for skydiving does not look good, indeed due to the small market. Let's turn the problem around: What helmets are out there in the world, used for other sports than skydiving, that meet some standards for crash safety (like EN 966, EN 1077 or EN 1078) and are suitable for skydiving use? I personally use a half-shell skate helmet that meets EN 1078. It is perfect for CRW, but not suited for freefall. The few times I took it to a longer delay than 2 seconds, it started rattling around on my head due to the high airspeed. And the fact that not all jumpers use the safest equipment available is eternal. We cannot change that, we can only try to educate as many as possible on what the best safety options are, and councel them to use it. Edit: A bit of google later, I've found something that's quite close to OP's initial request. http://www.icaro2000.com/Products/Helmets/SkyDive/SkyDive.htm. Anyone on these forums that have experience with this type of helmet? They say on the website it meets EN966.
  7. https://www.actiefstoffen.nl/ https://www.aktivstoffe.de/ https://www.activefabrics.co.uk/ FTFY
  8. That said, if I had to buy a jumpticket for every Dutch jumper who has a main that's on the limit of what he/she is allowed to jump, and a reserve that's quite a bit smaller (I've seen 190 mains and 160 reserves in one rig!), I'd be broke. I still fail to understand why people want small reserves... I'd guess there's a 50:50 chance of a >120 size reserve killing you if you fly it straight and level with toggles on half-brakes into the ground with no flare whatsoever. But what are the chances of that happening... /s
  9. My personal experience with a baglocked cutaway (no tandem) is purely theoretical, as the canopy is still camping out in the Estonian woods. But based on loads of talk with riggers, I concluded that the baglocked main went down like a homesick bowlingball, especially relative to a freebag. I chopped at 13kft in 0-5kt winds at altitude. My freebag landed 1500m downwind of my approximate exit point, and I think my main landed at most 50-100m downwind of that exit point, in part because my pilot chute was the culprit (it never did its bloody job, hence the chop). Due to inaccuracy in the exit point, I've got an area of 100x300m where I think my main is. All trees with heavy undergrowth. So, if you're willing to go search for it, I still have a €200 bounty on its recovery =).
  10. That canopy has room to rattle around in the freebag! Interesting that the Speed is so much smaller in pack volumes than other low-volume reserves. I assume it's either different fabric, different construction (less reinforcement tapes?) and/or different way of measuring size. If it's fabric, why aren't other manufacturers using it? If it's construction, what effect does it have on reliability? (unintentional reserve openings during freefly come to mind...). And how are sizes of canopies measured anyway? I know it differs from manufacturer to manufacturer, but can that really explains a massive size difference?
  11. Because....cold. You can't grip anything very well with numb fingers. As a CRW-dog, I absolutely LOVE having blocks on my rears. But it has its downsides, for example more bulk on the riser. That may look ugly on packing, or worse, prevent you from properly closing the riser cover. Also, it might prevent pulling down the slider fully. For CRW, we don't care for the extra bulk, it's peanuts relative to the crap we put on our front risers, and the big-ass toggles we have anyway. And good gloves don't encumber you. If you can operate a zipper with the gloves on, they are good enough. As a matter of fact, having good grippy gloves can help during EP's, since you can get a better grip on cutaway pillows etc.
  12. I'm using MaxiFlex gloves (clickety click). They provide excellent grip on risers & stuff, but they do tend to fall apart after a season or two. But for
  13. This will heavily depend on where someone is. In the Netherlands, accident insurance (for yourself) is included in the basic healthcare insurance everyone has. Third-party insurance (if you destroy farmer McNasty's stuff while crashing) is included in the membership of the association. Gear insurance can be bought, if you feel so inclined. I personally have extra accident insurance on my travel insurance, since not all insurers like the idea of us leaping out of aircraft. They seem to think it costs them money...
  14. But we want to watch! top Agreed - the most entertaining thread in a ling time. Aww man! I just got the popcorn out of the microwave!
  15. Rule of thumb for gloves: if you can operate a zipper with the gloves on, they provide enough dexterity for jumping. Do try to get something with some grip on the surface. Smooth nylon as the outer layer isn't good for securely grabbing a hackey or a handle. I use working gloves as the outer layer (with silk undergloves underneath that for warmth), which work wonders.
  16. Keep it out of the UV light by storing it somewhere not in direct sunlight.
  17. For european stuff, have a look at extremtextil.de I believe they have 3D spacer mesh as well.
  18. Yeah, but that only works when the canopy is attached to risers and packed in a d-bag. For those cases when you need to lug around a canopy not yet on risers and/or without a bridle/dbag/pilot chute attached (or even better, one that's supposed to be freepacked), those PD bags are too small. Best to use a transparent plastic bag. Transparent because a clubmate of mine once had his canopy stored in a standard dark grey trash bag in anticipation of selling it. Until his wife took out the trash... I don't really know where to buy them, every option that I see sells them per box (100+).
  19. Heh, then the rules are poorly written. Dutch regulations state that a functional, correctly set-up and during the jump readable altimeter is required, so shenanigans like that would be outside our rules. Que the discussion who needs to be able to read it, if you do RW and mount it on your ankle, your teammate should be able to read it ^_^.
  20. Yup, pick a landing area when you still have options. But crabbing will never get you further upwind than flying straight upwind. On the other hand, tucking in your legs (reduced drag) and front riser input might, because you are adjusting the airspeed of your canopy in that case, as well as the downward speed.
  21. I'd much prefer people look out after landing to see whether other jumpers are coming down, and whether they are on a collision course with you. Waste 30 seconds on every jump doing that, and it'll cost you just 10 days time over a jumping career of 30k jumps. Healing from one crash is likely to cost you at least double the time. And it's smart to occasionally check your steering lines for twists and untwist them, even if you stowed them immediately upon landing and know they haven't been rotated. I do it by default at the end of the day.
  22. Erm... Huh?? For sailboats it works because they have more than just wind force acting on them, they are in water and the water also acts on the boat. When flying, if the headwind is stronger than your forward speed, everything upwind might as well be on the other end of the planet, i.e. totally unreachable. For example, let's take a 30kt headwind coming from due south. If I have an airspeed of 20kt and fly due south, my groundspeed is 10kt due north. If I fly at 45 degree angles (either southwest or southeast), I can break up my airspeed into two components: one 14,1kt due south, and one 14,1kt due east or west. Now, my groundspeed is a combination of 15,9kt due north and 14,1kt due east or west. I'm actually losing penetration into the wind by crabbing back and forth across the wind line.
  23. Point 3 is just a packing error. Shit like that happens all the time. Until a proven perfect packing machine is invented, people will keep chopping because of packing errors. Point 1 and 2 are valid, but I'd say it's the combination that nailed you. When ground life is busy and exhausting, making a jump can be an awesome way to get rid of that stress. Just make sure you aren't rushed into it in that case. The other way around counts as well, it's fine to get rushed into a jump, but only if you are mentally not distracted by other stuff. One last thing: if you're the last jumper of the first group, it is perfectly acceptable to look out and say "f* this, I'll be the first jumper of the second group", and ask the pilot for a go-around. If the last jumpers of the second group don't like the spot, the pilot just has to do a third jumprun.
  24. You survived, and it sounds you made enough good decisions to offset the bad decision of jumping in those winds. Plus you gained experience jumping in poor weather conditions, which is also worth quite a bit. Next jump, you'll be experienced enough to say No when the winds are that high. As for aiming for the edge rather than the middle: as a low-time jumper I had serious issues even hitting the middle, let alone picking an edge and landing there accurately. Impromptu accuracy landings is a skill that requires lots of practice, I don't expect a
  25. http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4849571 Here's the other thread. Yes, it's possible to fly such a flag, but there are plenty easier (and less risky methods). I cannot shake the impression that flying a flag from your D-lines is a distinctly American thing to do, in order to avoid all sorts of nasty reactions when some fabric in a particular colour pattern touches the ground... If you want pictures of a simpler system, PM me. I have one that attaches the bottom end to your foot, and the top end can be hooked into your lines after a regular clean deployment. Picture is in the other thread somewhere as well.