pchapman

There's a bit of a discussion here about the tricky issue of which rule is more important, avoiding obstacles or avoiding turns on landing. It does end up depending on the obstacle (bush or power lines?) and the extent of the turn (moderate turn away, or bury a toggle?). And what's right for the first jump student may not be right for the student progressing to smaller canopies. I don't have a perfect answer to all this. At the DZ I'm at we put obstacle avoidance first, but after presenting the rules I try to give the students a little talk about what should be common sense (to skydivers). E.g., that if the student did end up close to an obstacle despite having been taught the idea of turning away in time, they would have to make a decision -- a fast turn that can break bones may be an OK choice if faced with power lines just ahead, but maybe not the best choice if it is a small tree ahead. The downside of some extra talk is that it can muddy up simple rules in the students' minds, filling students with too much info to digest. But I hope that it can be done well enough to help them better interpret the true meaning of the basic rules. It also may impress on them that they are using their minds to make safer decisions and not just blindly following some rules that were listed on the classroom board.

I don't like the first one down rule either. If using something like that, I'd prefer a more vague "do what others are doing if it is reasonable". Then people aren't fixated on the actions of one person. I figure it is better to have a plan ahead of time what the landing direction will be if the wind is almost zero, with "do what others are doing" taking over if a trend becomes evident among the first ones down. It's a good reason for all jumpers to try to become comfortable with landing in light cross- or down-wind conditions, as that will sometimes be necessary in order to play nicely with the other kids.

Just a curiosity here: The photo shows an MA-1 reserve pilot chute recently found in an out of service rig. The production location provides an interesting tie-in between faith in one's god and faith in one's reserve. I didn't know that Pioneer once had a production site there!

Hi Jerry, This isn't academic, I have a rig to put into service. It does have a single riser each side, with space for 2 links on each riser. The 550 cord cross connector came off another rig, a military style belly mount of some type. There it was inside the pack, between 2 of the 4 links.

Somewhere I saw it said that one should have a cross connector between both front links, and both back links, if it is a 4-connector reserve. But: 1) In my very limited experience I haven't seen rigs with two cross connectors. 2) The rig I was looking at just has 2 risers, with 2 slots at the top of each. So the front and rear L-bar connectors on each side, are right next to each other, and are well secured with a confluence wrap. It isn't as if there are widely spaced front and rear risers. So I'm thinking in this sort of situation a single cross connector, between one set of links only, is acceptable.

Simple version: Is it OK on a belly mount to have a short cross connector, between 2 of the 4 L-bar links only, built from 550 cord that's wrapped 12 times to create the cross connector? Long version: I'm trying to better understand cross connectors, and don't know what is actually normal practice. Some designs go between the snaps, some are longer and go inside the pack between the links. Is the inside-the-pack version considered the better style? Poynter (7.83) describes the standard design of 3/4" tubular inside 1" tubular. But there's also a pic of one that's like some I've seen where the cross connector is a length of 550 cord wrapped around multiple times, for a total of 12 strands for the one I have. The design looks professional - ends knotted with stopper knots and servings to keep it neat. This design is acceptable, is it? What about short vs. long cross connectors? Poynter mentions longer ones inside the pack to avoid getting a face full of connector on opening, but the ones I've seen are short, just long enough to go between the links on the reserve. I'm not sure how one would pack a longer one, with slack in it, to keep it neat in the pack and not getting in the way of the reserve.

You'll have to check the manuals but I seem to recall that Aerodyne mentions tacking their soft links in the Icon manual, but not in the Smart manual. (Smart reserves come with their soft links.) In any case, not being under FAA rules, I tend to leave reserve soft links un-tacked, just stretching them to try to seat them. I prefer having them inspectable. Remember all those rigs with rapid links that had no bumpers and no tacking? Links rotating, lines sliding around, contacting the barrel? I never liked that much but I guess when the reserve was used everything usually lined up properly and didn't cross-load the link (across the short dimension). Definitely uglier than un-tacked soft links.

My experience in Canada was that repack rates didn't really change when we went from 120 to 180. Perhaps a rigger might have decided that it was a good time to bump his rates up by $5 in any case, but generally the longer repack cycle was a non-issue. (Individual results may of course vary - as seen by one previous post from a Canadian)

So how about the oldest sport reserve in production, excluding rounds, excluding tandem reserves? Flight Concepts still advertises the range of reserves that includes the Fury. Does Precision make the Raven any more? They don't advertise it. (One can argue whether the -M counts as the same parachute as a Raven or Super Raven but I guess the TSO is the same?) I'd guess one of those two groups of canopies would be the oldest solo, square sport reserve in production.

True. The tricky bit is when the accepted practice in the industry is below the level of the FARs or manufacturer recommendations. If the manufacturer recommends no front loops out the door with a tandem, but all the experienced instructors do them, that can put one in an awkward spot.

Flare puppies !!! Seems a little cruel to use ... before they even had had a canopy that would flare.

Airtec seems to differ with you on that. [...] Here they specify 450lbs for the breaking strength of a loop and Hi Sam and Andre, I thought I knew the answer but now I'm not sure! Sounds like confusion over the strength of a completed loop vs. that of the material itself. The Cypres 2 manual mentions 450 lbs for a Cypres LOOP (and shows a photo of a completed loop) -- which is basically what 980's link shows. My spool of Cypres material says "185 kp" on it, i.e. kilopond or kilograms-force. That would suggest the 400-450 lbs value is for the MATERIAL. The Cypres Rigger's Manual mentions the MATERIAL: "Cypres loops are made from polyamide nylon cord and are specifically designed for use with the system. This is an innovative, very thin material with a diameter of 1.8mm and a breaking strain of approximately 180kp. " It sure does seem that it takes less than 800 lbs to break a loop, but I haven't calculated the numbers a novice rigger might apply on a torquing device. And loops only seem to break at their apex so I think there's the issue of thin cord slicing through thin cord with a tight bend radius, that is reducing the strength factor. Don't know how much. I'm tending to believe that the material is ~400 lbs, so the full loop is ~800 in the ideal world, but Cypres sure isn't very clear in their writing...

Looks like the rig is an old Vector I with velcro only and no tuck tabs for the reserve cover flap?? Pin checks sure are even more important with older gear! The pin looks bent in strange ways. But there might be only 2 bends. Hard to tell in the cellphone shot, but part of the apparent bend is just from the zigzag that exists where the free end of the cable is ground off. So it could be one big bend up (from hitting a bench sitting down) and then another bend of the tip down (maybe from then leaning back and partially 'flattening' everything out again). Whatever the details, it sure is bent....

Same as Slotperfect at the DZ I jump at, with about 10 Sigma rigs. That method gives good solid stows, better than regular elastics, without all the fuss of Strong rigs' design. Note that the canopies we are using are Sigmas with heavy Dacron lines - different from some tandem canopies. Shouldn't matter whether it's a Sigma or Vector II I guess.

I don't think the reason that it does not fire under 130 has to do with it not having time to open. It's for swoopers I believe the first answer is actually the correct one. "Below approx. 130 feet (approx. 40 meters) AGL opening is no longer useful. For this reason, CYPRES ceases operation below approximately 130 feet AGL." -- Cypres 2 User's Guide p 10 (and stated similarly in the Cypres "1" guide)

It's probably just confusion about a solo course (whether IAD, static line, or PFF) versus a tandem course. Mind you some DZs may tell people to be ready to spend the whole day there; it isn't always as if a booking at 10 am means you have jumped by noon. Even for the solo courses, one has to distinguish between the time for the actual course vs. all the associated stuff -- registration, taking a test, waiting for one's load, gearing up, etc. Places servicing Toronto are Parachute School of Toronto, Skydive Toronto, SWOOP, Niagara Skydive, and Skydive Burnaby. (And Grand Bend Sport Parachute Centre and Skydive Gananoque if driving more in the 3 hour range than 1-2 from Toronto.) Some are bigger, some are smaller, some have turbines, some don't, some are considered particularly strict with rules, but all are considered decent and safe places to go. I'm not getting into the politics of which to go to as I've jumped at all of them...

One reply: Those photos are the old standard. But one problem with them is that the camera angle on a few of the photos is from "ahead" of the risers, like from a belly cam, rather than "behind" the risers, as if one is arching and looking up at one's canopy. Therefore some have the risers coming from the bottom of the photo to the canopy in the middle, and some have the risers coming from the top of the photos. At my DZ those pics on the wall of the training room would sometimes get turned 180 degrees and then back again by different people. One either showed a view with the risers in the wrong place, or one showed the mal with the canopy facing the wrong way. I could be wrong about it confusing students. But it sure looked confusing to me as an experienced jumper.

One important addition to all the detail Erdnarob provided: The rapide links have a 5 times safety factor above the "safe working load". So a #4 stainless isn't just "good for 615 lbs", but has an actual minimum breaking strength of 3075 lbs. ================================== If one wants to delve further into all this: For the other hardware, the values provided (such as 5000 lbs for a big harness ring) are Proof loads. I'm not absolutely sure but I believe that that is supposed to be below the yield point, or Limit load in aviation parlance. Any of that other hardware should be able to be loaded to the quoted level without damage, without exceeding the yield point and suffering permanent deformation. Therefore the actual point of complete failure, the breaking point or Ultimate load, will be higher. (Roughly 50% higher depending on the metal and how the limits are defined.) So five times the quoted numbers for rapide links still can't be directly compared to numbers for other hardware. For a rapide link they care at what point it fails completely, while for a 3-ring, one also cares if it gets bent out of shape.

Chad, friend of mine, called me up early yesterday evening, looking for a reserve repack that same evening. He had just had his first chop, at slightly over a thousand jumps, and was looking to get back in the air for the rest of the long weekend (here in Canada) without having to borrow gear the whole time. While he promised to make it up to me, this was one of those inconvenient rigging requests that mess up one's plans for the day. He was at one DZ, while I was at another 45 minutes away (just passing by after a non-skydiving weekend) for a couple jumps before having to get home at the end of the day. I figured I'd help him out, as Chad isn't some random annoying rigging customer, but a friend who shares an interest in some silly skydives -- wingsuit rodeo, Para Commander Mr. Bill, double tandem Mr. Bill, playing with my intentional cutaway rig, and so on. So I agreed to head over to his DZ after jumping was done, but as it didn't look like I'd be on any good loads right away, I ended up packing up and heading out without another jump. Besides, "we" had C-182s, and "they" had a Caravan. I got to the DZ at 8:15 pm, just in time to make it on the last load. Sweet! Much more fun to jump at a DZ than only go there to do a repack. Chad kindly paid for my load, but stayed on the ground himself, chilling out and watching that last load. As I deploy after a decent sitfly jump, the canopy goes off heading early in the deployment, the risers cross, and soon I've got a few line twists. The story follows a rather standard course here: on my back in a deep spiral, futile effort to fix, chop, flip to belly, open reserve, land in field with I and another jumper successfully chasing all the stuff, and getting a ride back to the DZ from a local yokel in the bed of his dirty pickup truck. This was my first sport malfunction, although I had my first mal at the end of last season on jump #1998 on a tandem rig. (Plus there was a CRW related chop years earlier.) I guess I had had it coming, given that the main canopy is a Cobalt 75, kindly sold to me cheap by an experienced jumper who got tired of having to chop small ellipticals. (And upsized to a nice reliable Triathlon 99, which then spun up on her the same day I first jumped the Cobalt 75 -- that story at http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=3105615; ) The Cobalt isn't my regular canopy but I've flown it a bunch this year, just because it is sporty and different. As I joked, "Of course I like to jump it. What can possibly go wrong when someone sells you a 75 square foot non-crossbraced canopy for next to nothing?" Oh yeah, spinning mals. The gods sometimes really do have a sense of humour. I had shown up at the DZ to pack the reserve of a friend after he made his first chop, and after I made it on the sunset load that he covered for me, I had my first sport chop. Guess he's a demanding rigging customer, wanting proof that my reserve pack jobs work. Chad and I are then found sitting in the hallway outside the manifest office, filling in the official CSPA Accident/Incident/Malfunction forms, as if we were kids called to the principal's office. And still laughing at another little skydiving adventure.

But the Dactyl is still big enough to cover your body...

A good point. To expand on that: FXC's are normally, what, a standard $200 charge for the 2 yr service (plus $ for any fixes)? Thus $100/yr. Meanwhile a Cypres 1 averages out to say $80 for battery every 2 yrs and $160 for service every four, which is $80/yr. (I'm ignoring taxes, depending on where you live, and shipping charges which are appreciable, but would be held down by shipping in bulk for DZ's. Cypres' may do better on that front due to weight.) Also there's some DZ labour involved in doing chamber checks on the FXC's every 6 months, or even just once a season if the DZO slacks off a little. Yes the maintenance actually comes out in favour of the Cypres. But upfront costs favour the FXC. I think used ones are available for $50, equivalent to almost nothing per year. Without getting into the time value of money, a Cypres is closer to $100 / year to cover the purchase price, tipping the balance overall in favour of the FXC. Still your point is valuable - FXC's don't just sit there costing no money for maintenance, unless the DZO is unscrupulous. Let's face it, I think a lot of the decision depends on the gear. If you are buying a bunch of brand new student rigs, the company will probably laugh at you if you asked for FXC mounting plates. And if you already have 20 sets of 1980's static line student gear, you are going to leave the FXC's in, and not spend $1300 per rig to install Cypres' (and sew in Cypres pockets.)

Thanks, I think that's the first reference to a written source in the whole thread. On the other hand, that source does no better than just to say that "Small holes may be allowed, but consult the manufacturer's manual."

I'll go with those opinions about it being more common on canopies that are lightly loaded or on ones that open closer to a stall. When such a canopy is finishing decelerating vertically from freefall, it doesn't shoot ahead as quickly into fast forward flight, and so sometimes allows the pilot chute to drop right down and end up infront instead of streaming out behind. I've seen a light girl on a student gear with a spring loaded pilot chute have it happen a few times when nobody else on the gear was having the problem. As for fixing it, yeah you don't unless you're really into canopy trashing and backwards flight.

Some Parafoil brake lines don't even have an eye; the jumper just does a daisy chain like knot to set the brakes. If one has that situation, it leaves it up to the jumper to figure out the right position, and makes the brake line rather simple to make...

[...] There is a wind gust from the right and you can see the canopy yaw to the right, that is, into the gust. The following roll/pitch to the left looks like toggle input to me. So there are different views of what a canopy might to when it meets a gust from the side. I'm guessing that is possible that both behaviours can occur at the same time: a) the canopy yaws into the direction the gust came from (yaw stability), and b) rolls away from the gust due to the different forces / inertia / mass densities / ballistic coefficients / or whatever factors you want to include, of the jumper vs. their canopy. (The behaviour yuri_base described.) Without understanding the exact aerodynamics, it is quite conceivable that a gust could get the canopy swinging away from the gust, and then continue to swing side to side a bit until the motion damps down, but at the same time have it tend to weathervane towards the gust.