pchapman

It appears that the washer on the bungee for the new Sigma / Vector III staging loop can wear the reserve closing loop. The wear is at a place where it is normally not expected. The speed of the wear is unclear from my experience so far. It might become a lot worse if the sharp side of the washer is against the reserve closing loop. Details: A friend who is also a rigger noticed this issue on a Sigma tandem rig (after wondering about the possibility when first installing the bungee). The same might happen on a Vector III. When contacted, the factory said they are aware of the issue. For the Sigma / Vector III Skyhook mod from about the beginning of this year, one can add a bungee staging loop (hesitator loop) to better hold the freebag in place until the bridle stretches out. On UPT rigs, the reserve closing loop starts at a Cypres washer above the backpad, goes down through a grommet, across, and up through another grommet. The bungee is secured with a washer at that second grommet. So the washer of the bungee traps the closing loop against the grommet. My friend opened up a Sigma a few months after the staging loop was installed, to adjust the length of the closing loop a little shorter. Noticeable wear was found on the Cypres closing loop. It wasn't heavy wear but the loop was slightly fluffed up in just a few months. But it seemed worth noting because: a) Normally no significant wear of a closing loop is expected underneath the grommet at the backpad. b) On a Sigma it is less likely than normal for a loop to be pulled out for inspection. Because the loop goes down through one grommet and up through another, if a rigger happens to want to inspect the closing loop knots, the loop does not have to be pulled right out. c) This took place with the bungee's washer assembled with the rounded side upwards -- so the closing loop was trapped against the rounded side of the washer. Riggers have long known that sharp edges of washers can damage loops, so normally a washer would be put on a loop with the sharp side upwards, to protect a loop that feeds through it from a knot at the bottom. Therefore if someone followed normal rigging practice, because they didn't think about the implications in this particular special application, the wear on the reserve closing loop might be a lot more than my friend found. (The washer was the one that came with the bungee kit. I don't think it is any different than a regular washer, but I haven't seen it.) The online documentation on the staging loop mod says nothing about washer orientation. I'd like to hear what others are finding. Even if the wear is slow, it is an area to inspect regularly.

Yup, so we're OK.

How about a compromise, that both methods can apply, because some times it is also quite true that: You should not be spending all your focus and energy trying to force a student into the right body position when simply outflying them would correct the problem.

Funny you should say that, because later the same day...

Bored tonight so I'll add to the thread. Two pics of me flying a Paradactyl earlier this month ... backwards. I could have hooked up the risers to the rig a wee bit more carefully. Fun nonetheless. With a strong wind keeping ground speed low, the backwards no flare landing wasn't bad. (But I practiced holding a 180 twist to face the other way if needed.) Pics by Beatnik who was laughing his ass off.

I don't have enough practice with any of the techniques in actual high wind to be authoritative. I'll mostly tend to side with the standard skydiving approach here, but see some use in Dorbie's paragliding techniques. You land, you have toggles in your hand, so it is quick to let one up and haul one down to turn & dive the canopy into the ground. It's faster than turning around and getting on risers. (And of course there is the cutaway option in extreme circumstances.) If you aren't going to slam the canopy into the ground, at least on only moderately strong days, I do see that kiting the canopy above can make it easier to control the canopy. It's a neat technique. Some leave the canopy dragging behind them after they touch down, there's a lot of drag force, and they get pulled off their feet before they can turn around. Letting up on the brakes upon touchdown to kite the canopy almost straight above reduces the drag and makes the canopy easier to control in the short time until one can turn around. I'm not sure I'd want to keep kiting in extremely strong and gusty wind, but it is decent for the very short term. (While drag is lowered when the canopy is properly kited above, remember Dorbie that we're talking about lower L/D than for a paraglider, so I think there's more drag, making the skydiving situation is a little more awkward in that way. Although of course one will have it much easier for a given wind speed if using a small canopy vs. a large paraglider.) Anyway, if one kites the canopy just long enough to turn around, then yeah it should be easier to stall and drop the canopy on rear risers than on toggles, if trying to drop it symmetrically and not slam it into the ground nose first. I'm either trying to take both sides here or argue against both sides. I don't mind the "toggle into the ground" idea as the basic plan to teach, with ideas like kiting and rear riser stalling as valid things for people to try and learn and experiment with. That's best done in strong conditions but not actually when in danger. Just my opinion.

I also slip my leg straps forward, allowing more input when bringing one leg down. And for better turns the chest strap should of course be loose.

Kroops were a standard way back, but they had straps that relatively quickly wore out, losing elasticity. Did they improve?

I agree that this makes little sense. The closest it can come to working, is if one is talking about open canopies down low in an area of low wind, behind the aircraft. Then the plane may be crawling across the ground in the high uppers, upwind of the DZ, canopies open up over the airfield, and stay there in the low lower winds. Since the high uppers are only experienced during freefall, the spot isn't all that far upwind, so the airport is relatively close to 'below'. So yes a long time between exits is needed which matches modern theory (ground speed minus lower wind speed is very low). But as they exit the groups are still going to going far behind the plane. (Or do late divers on speed stars in strong New Zealand winds somehow all have to dive straight down?!)

Yeah, one is less comfortable at first with tandems, just as with coaching students or doing video or any new skill. One ends up having to work at it a lot more at first, thinking harder to keep ahead of things, when later on it becomes more routine. Some thoughts (as a tandem instructor and video flyer): -- Don't get complacent when a few tandems start to go easily -- out of the blue you'll get some big challenge, a problem student, or catching the wind in a weird way on exit. There are plenty of things that you'll deal with eventually, but that only show up at rare intervals. -- Work a little more with your students to make sure everyone is on the same page, that they'll cooperate with you, because you may be less able to deal with them going knees up on exit or doing the wrong thing on landing. -- There are all sorts of ways to do tandems, and DZ's vary a lot in what is "acceptable". Some may prescribe a certain exit; at some all sorts of exits are done. It is nice to have some direction from the DZ as to what standards to keep. It's tough to learn what to do if nobody tells you what to do. (e.g., "You screwed up. You shouldn't be doing that at your level!" "How was I to know that? Nobody told me that, and I see other instructors doing it".) Not sure what the lesson is here other than to keep asking questions. (In a related matter, it is nice for the tandem instructor to know what's allowed for the video flyers -- what is acceptable vs. too much "I love me" screwing around on their part.) -- Have patience with throwing the drogue. That's a big problem, and seen with some experienced but sloppy tandem instructors too. There's too much tendency to try to whip it out the same time on every exit, without thinking of the circumstances. That includes people tossing the drogue "when they are belly to wind" , who fail to notice that they aren't actually in a stable belly to wind position. They just happen to be passing through belly to wind, they start to toss, and by the time they let it go, they're head down or rolled to the side and the drogue goes out by their feet. -- Look to learn some of the "tricks". (Why do fat people sink deep in the passenger harness? What might you do with the chest strap to anticipate this? What are a couple reasons the occasional passenger might go unconscious? What options do you have if the passenger has a problem raising their legs when practicing for landing?) -- Take the side spin training seriously. Even if you're going Sigma, make sure to watch the Strong video. -- Be careful of too much maneuvering just before landing. Tandem canopies are maneuverable enough but it takes a bit of time to recover from a dive. Same goes for holding brakes for accuracy reasons, then letting up to get speed again for the flare. It is easy (well, it'll depend on the canopy) to get stuck trying to flare when the canopy is still in a bit of a dive or still trying to pick up speed again. -- Student harnesses can be too loose of course but can be too tight too, whether at the shoulder attachments, chest strap, belly strap, or hip attachments. Work on learning what a good range is. -- Remember the little things to make the passenger enjoy the ride. Even if the instructor is completely "safe", the experience may suck for the passenger if say they didn't know to get the goggles seated right down around their nose. So they spend the whole freefall squinting and with the goggles digging into their eye sockets. -- Use a jumpsuit, one with some bagginess on legs and arms. In later seasons I didn't mind going without a suit, but early on, control was somewhat lacking when trying to maneuver the bulk of a tandem pair with bare arms. -- In most aspects of skydiving, subtle movements are important. Whether doing RW or freeflying, less experienced people making large motions are often overcontrolling. With tandems, to control the mass of the tandem pair, it helps to use all the control power available. Don't by afraid to stretch the arms and legs way way out, grab air, whatever it takes to get good control!

Hi Wendy, The closest I have is a compilation someone made of dz.com landing fatality reports. See attached. I can't find the original post so I don't know who to credit for doing the work. The reports are still in their original form so they are messy and don't highlight experience and wing loading neatly. But it is a start. And the list is a long, long one to print out and put in front of the jumper.

So there I was a couple weeks ago, a friend and I are in the door of the Caravan. The door is open, the green light goes on, and I keep looking around, looking out the door from time to time to check the spot. A bunch of others in the plane start shouting "Green light! Go! Go!" and stuff like that. The silly thing is, we couldn't hose their spot even if we tried. We were the only two getting out on the low pass; everyone else was going high. Our spot had nothing to do with theirs! Let me figure out a decent spot, then they can keep rocketing up in the 900hp modified Caravan. Maybe the others didn't realize we needed a bit longer spot because the winds were up and we were jumping Paracommander or similar canopies. You'd think the belly mount reserves might have clued them in that we probably weren't going swooping...

Yikes. Soft PD line material? Presumably on a reserve that was used, after which the happy-to-be-alive jumper didn't stow the toggles on the velcro, and let the lines get all chewed up? Or were the velcro toggle covers badly folded, chewing the lines when packed?

The original location for the doc is invalid but it is at a slightly changed location: http://www.skydivewithjohn.com/documents/HistoryofHALOOperations.pdf

From another thread, by d123, but deserving a thread of its own: While snagging things on doorways is not new, it looks like the video deals with snag point that is becoming more common. The video shows shots from the jumper with the problem and another jumper on the plane. It seems to show an exit from a small Cessna with a snaggable door handle or latch. The jumper, wearing a Vector III, catches the upper part of his pack on the handle, pulling out the Skyhook RSL, popping the reserve. The reserve deploys over the tail, might be shredded, jumper and reserve fall away, jumper fights uselessly with the tiny spinning ball of garbage that is his reserve, eventually deploys his main, it clears the garbage, he doesn't die. Compared to the early 90s, these days jumpers have gotten used to much better pin protection, and I bet are less likely to expect to snag things on the back of their pack. I only know what I saw on the video but it seems like the handle caught the RSL line where it goes from under the riser covers to under the reserve pin cover flap. The Skyhook RSL is sometimes a bit visible in that area on rigs. RSL on some rigs are not exposed at all on the back due to the flap design. Whether it is a plain RSL on a Vector II or a Skyhook on a Vector III, the RSL is a little more exposed on those designs. So it isn't a new hazard but one that's becoming more prominent, given the increased use of Skyhooks after a time where RSL's were not so popular. Having a really scary video always helps drive a point home better!

I think that one's good enough for its own Gear & Rigging thread. Will start one there.

No problem, I saw that. I just meant that in general, jumpers should learn to detect that sort of thing themselves. For example, how much slack is there in the brake lines now? Peter

Too long brake lines? It has already been suggested that someone else to test the canopy (not doing accelerated landings), and to test the stall point yourself. You can also have a look at the brake lines while flying. How bowed out are they at full flight? How many inches do you have to pull them down before you start actually deflecting the tail of the canopy? While that doesn't say anything about the stall point with your length of arms, it is a guide to how the brakes are set up. Every jumper should be aware of that slack amount on every canopy they fly, but many are not and haven't looked or thought about it. It is surprising nobody at the dz mentioned the possibility that the brake settings could be the issue, but they may have assumed that factory settings were used and should be sufficient, because it is a brand new canopy. (What does PD do with new canopies? Mark a suggested toggle point? Does it tend to be on the long side to avoid being on the short side?) If people were saying 'you weren't flaring all the way', one has to distinguish whether they just noticed the resulting bad landing and assumed that was the problem, or actually saw your arm position on landing (whether or not the brake setting are correct or not). Like other answers, "Get video!" too.

I have a "locking stows only" bag too. I was able to sew the line stowage pouch right onto the existing bag's seams. Although it seems friction holds the lines in place, there are two tabs to secure the mouth (ballistic cloth inside the tabs). I do have the compromise of a velcro closure part-way "up" the pouch, so it opens up easier to stow the lines inside. 500 jumps on it, no problems, velcro is still good enough (since it is only opened for packing, and not suddenly sheared open like some riser cover velcro used to be.) There may be better ways to implement a line stow pouch, but what I have works.

Great to hear, that's something I hadn't yet asked the factory about!

Further to mdrejhon's post, some trivia for the day: The Cypres 1 and 2 manuals do not contain the word "arm" anywhere. They do say that the Cypres "will not work" if one exits below 1500'.

Welcome aboard. Judging only from your original post, it looks like trying to come into the sport with a little humility (about skydiving) and an open mind, which is good. It can be a little tough mentally for someone who is shit hot in one adventurous sport to start right down at the bottom of another. Of course skills in physical body control, evaluation of risks, thinking under pressure, and so on can transfer over and help speed one's progression. But there are some people out there who become annoying, and dangerous to themselves and others when they try to do too much too quickly, after having been involved in other sports. Although everyone is different, that's one of the categories of new jumpers that skydivers know is out there!

A recent thread on just this thing, with many people saying how easy it is to self-induce line twists even on big docile canopies: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3620791;

Impressive, Howard! Jumpers going backwards at a 45 degree angle on landing approach... I started the thread because I knew I'd meet Beatnik this past weekend and we were going to jump old gear if at all possible. Although the uppers were strong and there were some student wind holds, ground winds were I guess only gusting to 15-18 mph. Even if being pushed backwards quickly at 200', I was happy to find that down below 30' there was enough wind shear so one usually ended up going backwards only slowly on landing, which is far more tolerable than what's in that video. And even if one doesn't have the skills to truly hook turn a Para-Commander, one can still drive downwind and make a pivoting turn at quite a low altitude to get facing more into the wind for landing. My limited experience from the weekend is that Para-Commanders seem to handle turbulence well, although a sudden gust could get one swinging unexpectedly? Among the ram air jumpers, enough of them were getting their canopies bounced around or giving themselves bad landings. Beatnik & I got 7 jumps each on a variety of Para-Commander, Dactyl, double keel Dactyl, Thunderbow, and a complete UT-15 rig. I even hooked up the Dactyl backwards by accident and landed it that way. (Didn't flare but they hardly flare to begin with, and the canopy ground speed was low.)

I have to conclude the same. Based only on my experience, this canopy peforms poorly, but I have read reviews by those who had better results. I test-jumped a very nice, low-mileage Jonathon 120 loaded at 1.5, which did everything well except landing. Yet the one I flew landed great -- so I agree with Captain Stan on the hit or miss thing. The Jonathan 92 I jumped in '95 or so at 1.8 wing loading planed out and landed fine from full flight even on a hot no-wind summer's day. Since I had 200 jumps and only had a dozen jumps on anything loaded over 1:1, it can't have been that hard to land. But it did buck if one tried to front riser it (although I don't know if anyone had changed brake settings.) AirTime Designs (or whatever the company name was originally) was known for being innovative but also for constantly adjusting and changing things.