pchapman

In my particular case the user is taking the PC out of service, because good sized holes had benn worn into it. Not sure how, as I wasn't the rigger before. Who knows, from the stains, it may have been pulled from a tree or something after a cutaway. The best I can see so far: - There's no standard number out there for hole size. - A 'small' hole could be hand sewn shut. - Hand sewing a patch on a larger hole might be feasible but fiddly. - Any damage that is questionably large? Replace the PC. With appropriate skills it may be possible to rebuild the PC fabric using the same cap & spring. All sorts of options are possible.

What is considered acceptable for torn holes in reserve pilot chute mesh? I've come across an older PC where there is damage to the mesh. It's a soft type of mesh with hexagonal holes. On the one hand, it isn't the way it was built and TSO'd. On the other hand, most things have acceptable wear limits. (E.g., consider all those Javelin PC's one sees with fabric looking rather porous and stressed from their packing method.) I can't recall if anyone has suggested a specific limit to hole size.

I saw an interesting situation once in Canada. The DZO didn't have a commercial licence, but flew the occasional load. Everyone considered it normal. He figured it was justified because all the Operations Manual paperwork, which was approved by the government, shows him as the Chief Pilot. The legality may be a iffy when it comes to having to fulfill all the applicable regulations. But he can say that the government, who knows what licence he has, specifically allowed the company to do things a certain way according to the Operations Manual, and that includes him flying...

Of course many people didn't really make any choice of handle -- they use whatever came with the rig. Preferences translate into actual equipment only for those who bought a brand new rig, bought a new PC, or (very rarely?) actually had a rigger change handle types.

There's little point jumping in high winds if there are other associated risks -- like dust devils, an approaching thunderstorm, or really strong gusts. But one could certainly work ones' way up, gradually getting used to jumping in stronger winds, in situations where the wind is judged by experienced jumpers to be unpleasant but not particularly dangerous. One doesn't need to learn to jump when most others are standing down. But there are times the wind is strong, most people are jumping, yet some are afraid to jump and choose to stand down. They may be unsure of themselves, unsure how to plan their approach, or squeamish about any turbulence and bouncing around under canopy. While nothing says one has to jump at any time, it can be handy to be comfortable with dealing with stronger winds. So, yes, I'd recommend slowly starting to jump in higher winds. Coaching and advice beforehand could of course help. One needs to figure out what is just scary (because one isn't used to it or trained for it), versus actually dangerous. For many years I jumped a big accuracy canopy and I never felt I had to stand down before others did. It just takes more planning, and does make the landing more of a challenge than easy fun. These days there seem to be enough newer jumpers who are afraid of moderately strong winds because they don't think they have a high enough wing loading, even when one could quite easily and safely go up with a student canopy, if one flies it right.

I have no problems with that post but have to add that it is hard to make a scientific or rational judgment with imperfect information. Say there are two devices: -- Device A: 10 years of sales 1000 units a year sold (=10,000 total) major safety problem with 2 units, 5 years ago -- Device B: 5 years of sales 1000 units a year sold (=5,000 total) major safety problem with 1 unit, this year What do we "rationally" conclude? Both are equally safe, 1 incident per 5,000 sales? Or does one need to factor in how long a device has been in service (due to gradual failure of poor electronics), not just whether that device is fundamentally good or fundamentally bad, waiting to fail? (Device A has been around longer and has over 3 times as many unit-years in service than device B, a bigger ratio than just the 2 to 1 sales ratio.) Is device B safer because the company has had only one failure, one time that they screwed up? (What were those failures of device A: Were those failures related or not?) Is device B no worse than device A because every company makes mistakes in its early days before refining their product? Or is device B less safe because by now the industry has matured and that company shouldn't have screwed up like device A's company did "in the old days"? Is device A safer because it has been problem free for 5 years? Is lack of a problem since then evidence that something has been fixed? If something needed fixing, was it symptomatic of other problems at the company and latent flaws? Or if they said they fixed something, does that show their responsiveness, competence, and concern for the user? Is it a fundamentally flawed design or is something easily correctable? Or were all failures random, due to problems at the limit of any company to build complex electronics perfectly? When events are rare, it is hard to know whether the events we see accurately reflect the true probability of the event. (E.g., Someone has 1 mal in 2500 jumps. Is he lucky or does he pack better than average? Hard to tell.) If the failures were random, can we expect 1 in 5000 of device A or B to fail in the long run? In the end this super simple example with clear facts defies rational or scientific explanation, because there are so many underlying issues about the nature of the failures not known to us, and possibly even to the manufacturers. Then we get emotional about these things, trying to pick out which facts take precedence over others, because of what they might imply about what we don't know. And if you think device B is not quite as good, but is cheaper, how does that factor into things? That gets into a whole other mess of drawing utility curves! In the end, do you pick the device from those arrogant secretive bastards who traditionally kept denying the chance of problems yet still had them? Or do you pick the device from those upstarts with the cool new product but with questionable design decisions early on?

What the heck, I'll bite. Compared to "normal" canopies of moderate size, small crossbraced canopies are: a) fast in forward speed b) drop out of the sky with a high descent rate c) are sensitive on the toggles and d) easily dive steeply in turns (Opening also can be worse, in that when something goes wrong, the malfunction is likely to be more violent , disorienting, and fast descending.) For a small crossbrace, you have to have the awareness and knowledge to quickly plan ahead, because you're dropping out of the sky quickly, and will do so even faster as soon as you start turning to set up a landing approach. I recall my first crossbrace jumps on an FX 88 when I was used to Stiletto 120's and the like. As soon as I popped the brakes after opening it felt like the floor had dropped out, as the canopy accelerated forwards and downwards. The wind noise was far more than I was accustomed to, so I was thinking I just about had to start wearing earplugs just for the canopy ride... On landing I had to accurately go through the flare motion to get rid of the massive rate of descent to level out at the right height just above the ground, a job that was a little tricky the first few times. It didn't help that compared to many canopies at the time (~2002), a lot more toggle motion was needed to get that flare happening, so there was a tendency to get caught by not bringing the toggles down far & fast enough. The sensitivity of the toggles resulted in some see-sawing on the toggles on a couple landings - I had to learn to focus on keeping the toggles absolutely even if I wasn't to dive off to the side while planing out. All in all stuff just happens really fast and unless you know what you're doing, you're going to hit the ground really fast...

I was wrong. For the record, Rob was not on a board on that last, 3-canopy jump. This is based on a PM from someone there at the time, and Douva who has posted skysurfing history on this site. Douva put it well in a good skysurfing risks & history thread: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2236438

Not literally true but there is that element of truth as a sarcastic offhand statement. I really don't know the history of this but a quick list is: Jerry Loftis (while skysurfing) Rob Harris (while skysurfing but accident unrelated to the board) DeGayardon (not skysurfing) Laurent Bouquet "Silver Surfer" (not skysurfing) So they may have been out there pushing the limits and doing a lot of good skydiving, including pioneering skysurfing, but it wasn't usually skysurfing that killed 'em. [edit - corrected Harris info.]

It's an easy question for me as my DZ has had the good fortune to have zero fatalities in 35+ years. I tell the students to pay attention to what they've been taught ... so they don't screw up our good record!

Never got my glider licence. But I spent weekends as a kid camping at a grass airstrip where my dad was a glider instructor. And now I spend weekends at a grass airstrip skydiving. I find it curious how close in performance the bottom end of glider flying is to the top end of skydiving. My small crossbraced canopy flies about 46 mph in full flight, and obviously more in a diving swoop approach. A slow Schweizer 2-33 flown solo has a typical approach speed of 55 mph, starting the flare at 50-45 mph.

I've always wondered how one easily replaces the elastic for the mouth of the Wings Cordura BOC. I haven't looked at one closely lately, but it doesn't look like it is made for easy replacement. Most seem to last fairly well, but I've seen ones that are stretchier then a decent Spandex BOC, which is a concern when they grip the PC only at the mouth to begin with. With Spandex BOCs one can just remove the stitches and sew a new BOC on. Modern heavyweight Spandex (or Spandura or whatever) BOCs do last longer than the old thin ones did, so I've done fewer BOC replacements in recent years than I used to.

I'm a little confused on the angles and directions implied here. Why would it be much different than a normal downplane? As soon as separation is initiated, the jumper just swings down under his canopy as the canopy levels out. Due to the initial dive the canopy would temporarily plane out to less descent than normal descending flight. Or were you thinking more of a dragplane, say if there's a HUGE mismatch between main and reserve, like a 302 Parafoil and a PD113 perhaps? In any case CRW people do successfully drop the bottom person on a dragplane and they do avoid falling into their canopy. Sure I could see that because of the messed up body position one might spin one's body into line twists, if the reserve hadn't already twisted when it first came out, depending on how the 2-out happened. And there would be a chance of getting feet in the lines since the small reserve would be down low somewhere below the horizon, before one chopped.

Merry Christmas!

The Storm sure isn't being marketed as a boring 7 cell. Their max recommended wing loading works out to 1.8 for the Storm, vs. 1.7 for the good old Stiletto, and 1.6 for the Spectre and Sabre2. (This is for the 97 ft size only; I didn't check other sizes.) Obviously attitudes to wing loading have changed over the years but still this says something about their confidence in the design.

Idea: DECOUPLING REPACK and INSPECTION CYCLES: If there were data like Councilman24 discusses, we'd want to look at what aspect of the pack cycle is being evaluated. Are we thinking about: a) the ability of the reserve to open properly, b) the condition of the reserve in its pack tray, or c) the condition of the harness/container The limited info I've heard suggests that opening speed or reliability doesn't change much once the canopy has been packed for a while, and that isn't going to change much whether it has been packed 120, 180, or 365 days. Say that one accepts that. Then part (b) comes into play. One has to open the reserve container to look inside to see whether the tray is full of desert grit or swoop pond sand. If one is confident that the reserve container is going to be clean inside, what's left? It's mainly the condition of the harness/container. There's no need to repack a reserve to do a detailed inspection of almost all of the rest of the rig. The rig condition is a separate issue from reserve reliability. (Actual repairs of course tend to be much easier with the reserve out.) So the guy concerned with tandem rigs getting chewed up at a busy DZ may not actually be arguing for a 120 day repack cycle. He might argue for a 90 or 120 day inspection cycle, and a lot longer repack cycle. Theoretically one could have something like a rig inspection every 90 or 120 days for commercial equipment, and a full repack every 180, 240, or 365 days. That rig inspection may or may not include an open & reclose on the container (without a repack), although that creates issues in the current legal & operational environment. This concept is a bit radical and not about to be FAA implemented, but I think it is useful in understanding some of the different feelings about repack cycle length. If there is concern over long repack cycles, especially for commercial gear, a DZ (or the USPA) could create a formal inspection cycle that is shorter, which does not include a full repack.

Maybe you're getting fooled by your instrumentation? Vertical speed measurement gadgets do have some limitations due to the messy airflow they can be in. For example, for short breakoff tracking after RW, my Protrack mounted outside my Protec helmet typically shows a big rise in speed up to 150 mph or the like. This is clearly a temporary artifact of changed body position. (When I do long tracks for the whole jump I get sub-80 mph, so I know how to track.)

The second poster is right. A quick and cheap alternative I've used for customers is to slip extra padding in between the leg straps and their covers. Sometimes one can fiddle it in by hand, in other cases one removes and resews a short piece of stitching that keeps the strap and cover together at the lower end. But finding a source of thin padding might be tricky. I happen to have a very thin closed cell foam camping pad no more than 1/4" thick. That or thinner can work well. Yoga mats might be another type of source.

Riggerrob has come out east from time to time for a course, but not every year. Another jumper in Ontario went to Chicago for a course, and does all his rigging here in Canada under his FAA certificate. Despite the course, he still found it very useful to have apprenticed a little with someone here first. One minor issue is that he feels much more constrained to do things "by the book", because that's a requirement of the US rating.

Yes. Maybe we're both hoping someone else will spend the time to catalogue on a web page a list of all known problems the manufacturs have had, the dates, the manufacturers' responses, and so on. Even with facts, interpretation can be tough. Does Vigil get free reign to make mistakes for the next decade because Cypres already has made mistakes for at least a decade and a half? Both companies have had very recent bulletins and notices on inadvertent firing. At least Cypres produced their own bulletin. Vigil only wrote their "open letter" after the FFP told the world about the problem (even if there are politics involved.) But then Vigil claims both companies knew about possibly defective sensors from a supplier in 2006, and only Vigil acted on that information! An interesting battle. P.S. - Andre / erdnarob, I finally realized who I'm arguing with!

I dunno. Sounds like they just haven't updated the manual. Jeez, no big deal. I know you like a lot of precise technical detail. I trust you're not actually too surprised when manufacturer instructions conflict, state impossible things, are unclear about which gear they apply to, are unclear about the precedence of different publicationn, have confusing designations, are missing dates, show outdated techniques, show excessively restrictive techniques that nobody uses, and so on... (Yeah we could get into the fun argument about how FAA riggers in the USA must follow manufacturer instructions. So they have to pack a spare Cypres cutter into every G4, at the #1 flap...)

Similarly, I'd hope the atomic bombs weren't Vigil activated, just in case the flight crew slammed the cockpit hatch after climbing in. :) Despite Airtec's sometimes frustrating level of secrecy or unwillingness to admit problems over the years, my personal opinion is that they still seem to come out ahead of the Vigil in terms of reliability and doing what one wants them to do. Even if Airtec has secret parameters or secret potions, I still trust their algorithms, reliability, and engineering a little more than for AAD/Vigil.

Another thread where I added some ideas: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2866920;search_string=GQ%20security;#2866920 Plenty of interpretations possible as to whether the service lives are mandatory or just suggested, and whether new instructions apply to old products, and whether current company policies are different than old company policies.

[thread drift] You can pressurize a B-29, but the bomb bay is not pressurized. Hence the little tunnel with a cart for crew to transfer between the front and aft pressurized sections. [/thread drift]

Any special tips for dealing with that final heavy but smooth opening shock one gets with a ParaCommander? Just the usual need for low airspeed and good grips as with any Mr Bill? (I had a failed attempt last year -- too much speed after tumbling once after exit before deploying.)