pchapman

FWIW, for the rest of us, the public report on the Mark T. Urban test jump accident of 2013 can be found at: http://www.wildfirelessons.net/communities/resources/viewincident/?DocumentKey=a7aa252b-85dc-4c03-9cce-b73a43301fa2 "Smokejumpers were performing extended drogue ride parachute jumps for research and development (R&D) purposes " The main report is 111 pages. As for confused AAD's, someone could dig up the threads but it involved a C-130 doing pressurization stuff while on descent, to an apparent altitude below ground level. It was World Team 2006. Both Vigil and Cypres made public statements afterwards, see below. C1's detected pressures outside the normal range and so concluded there was an error so the best action was to shut off. C2's were more advanced and decided it wasn't a permanent error so stayed on and did nothing. Vigils got jumpy and fired. Cypres: http://www.cypres-2.com/cypres_news_letter_feb_2006_c.pdf Vigil: http://www.vigil.aero/wp-content/uploads/VigilStatementAUG06_000.pdf and https://web.archive.org/web/20060714212226/http://www.vigil.aero/pdf/WorldTeamResponse_004.pdf (They seem to have cleansed the original document from their site, hence using archive.org.) Do electronic AAD's have any accelerometer at all? If so, it isn't something talked about by the companies. Supporting data? Interesting research you've been doing.

... Moving her up from maybe 0.8 wing loading to a crazy 0.9. (if she is say just under 100 lb + just over 20 gear +15 lead) Mind you I can understand if one had crappy landings and fell over all the time, an extra 15 lbs wouldn't be fun on the ankles.

You mean both tandem jumpers in wingsuits, or?? I don't know the history, and I thought someone in the US was playing with it too, but here's a small photo and article (in German) from a jump at the Cochstedt boogie: http://wingsuit.de/wingsuit-tandem-project/ Edit: But it was just a tandem wingsuit jump, not a tandem headdown wingsuit jump...

Hey Remster, I know you've mentioned that new style before. Just like a mantis, a more "unstable" position still works fine if one learns to deal with it. But how soon are experienced coaches recommending it? I know one can teach mantis in the tunnel to someone with zero jumps. But at the average dz I'm not sure how the average instructor is going to fare if they're the only person telling a newbie they can not just relax their arch but dearch at the hips. And if one is flying somewhat cupped as one's neutral point, does that not make it a little harder to slow down more? No problem if one is with one's 4 way team all dialled in, but is it maybe a little tricky if with random jumpers? After all if the original poster were trying on some jump to speed up and can't, it might be partially because he doesn't realize his legs are too wide to add arch. So the idea you mentioned makes sense as a more "advanced" technique (whatever that implies), but as with many new ideas, it is hard to be the only one to advocate something - especially from early on - if the rest of the system doesn't support it yet.

Tapping heels together is a standard way to focus attention on what one's legs are doing, out of sight. You can also fly with legs pressed completely together for a while. At this stage (60 jumps), you don't need legs super wide any more to stay upright. Then after flying that way, relax them outward a little from that. Legs together is also a trick for more arch if ever needed, as one can arch more at the hips with legs close than wide. If your legs are typically really wide, it is also possible you don't have any arch at all at the hips, so changing the legs might change your fall rate a little, depending on what you do. Edit: Not being able to drive forward can also imply too much arch given to the upper legs, so just putting lower legs straight still leaves them sticking too much upward. Although that's less likely to be possible if legs really are way too wide. Am surprised this didn't get sorted out in your tunnel time ... but everyone gets some bad habits.

I always thought it was a rather clever solution to save space. And whether there's any loss of strength for whatever reason you didn't think of, well, that's why you put things into a pull test machine to check your new design.

There may be directory printer freeware out there. One can normally print or send to a text file. I have a couple ancient little programs like that, that I use if trying to get more than a simple list of file names (for which R click, Send To, Clipboard as Name is sufficient at least on older Windows versions). Hopefully the software has the right selections to be able to print all the attributes you want. I can look at what I have if nobody else knows something offhand, or if you don't find something on Cnet / downloads.com.

To speculate more, like most of us here: CURRENT OUTPUT TO CUTTER It is so hard to argue things because the manufacturers give us so little to go on. So we can say, hey, the Tadiran Pulses Plus hybrid battery/capacitor in the Vigil 2 is really neat, and works fast. Heck I found a Vigil document where they claim an even faster "under 1/1000th of a second" from fire instruction to cutting the loop. But they don't say how the competition works, and neither does Airtec about the Cypres 1 or 2. And how fast is the discharge from a capacitor vs. a battery? What current can it achieve while maintaining voltage? I don't know. Pulses Plus battery/capacitors of size similar to that in the Vigil are in product literature listed as being able to have 1A pulses (up to 1 s, maintaining 3.0 V). A battery similar to one of the two in a Cypres 1 is similarly quoted as being able to sustain 2A pulses (quoted for 0.1 sec, maintaining above 3V). (But I don't know for sure what type is in the Cypres 1). So just on published data, it makes it look like Cypres batteries could well provide a high current too, although rate of onset is still not known to me. Someone with knowledge of pyrotechnic line cutters might have some insight into what kinds of electrical flows are needed to set off the charge. FIRING DELAYS Now if the Cypres 1 and/or Cypres 2 do rely on a capacitor (which we're unsure of), they will obviously have taken charging time into account. Really, how long does it take? I don't know. Is it really more than a small fraction of a second, and either way, wouldn't it be done before the decision to fire, getting ready for a possible firing, and not as some afterthought? If one argues about firing time, then one should also look at the delays induced by the overall algorithm, which might be a lot more significant than the delay in getting the firing command executed. From the little I know, any traditional smoothing algorithm that in some way averages results will be a little "behind the times". Any sudden change in one measurement period can't be taken on face value; it has to be interpreted in terms of prior data, and so delays any decision. To get more complicated, one can try to add some intelligence and do some prediction of what future values are likely to be reasonable, and compare that the incoming data. (Very roughly that's getting into Kalman filtering.) The Cypres patent from ~1988 doesn't give any clues, and I haven't tried looking for any of the Vigil patents. VIGIL ALGORITHMS Sometimes bits of data slip out. Consider this in a document from Vigil about the firings of Vigils in a pressurized C-130 at the 2006 World Team event, where the Vigil measured an apparent speed from the pressure change, that had a peak above 78 mph: The Vigil when in airborne mode does 8 readings a second. In another document, Vigil wrote: Also: These quotes are about the "door open" accidental Vigil firings, where it had to both decide the jumper was out of the plane and then decide there was a high freefall speed. The quotes can be found in "Official_AAD_Statement_Jun_2010[1].pdf ", which is on dz.com. I actually have them also in a longer document which was called "19sep2010_Vigil_PlaneCrash". Not sure where I got it from - not even showing up on google - but it internally claims to be a draft report for internal use only at Vigil. (It even quotes a section of a dz.com thread.) So the quotes make it sound like their algorithm takes 7/8ths of a second of data to decide that an apparent firing speed situation is true. What does that imply? That even with perfectly smooth data they always fire 7/8 sec late? They can't be that stupid, so do they basically start the count higher than activation altitude? But in the first quote they talked about 7/8 second WHILE below 840 ft, NOT that it counted activation speed for at least 7/8 second and then by the end noticed it had reached 840 ft. Their statements are all very confusing. Vigil also talks about their "time remaining" calculations as part of the algorithm process, perhaps predicting when the firing altitude will be reached, rather then depending entirely on noisy pressure readings. I haven't tried to read up or analyze their claims on that. Anyway, whatever the issues are with completely hidden Cypres algorithms, Vigil either has a pretty slow and crude firing algorithm -- or gives really confusing descriptions of its firing process. Despite Vigil crowing about super duper fast firing circuits.

You've got a lot of speculation in there... but on the other hand, nobody has a good handle on exactly how the various factors add up to cause failures to save a jumper. Given that the FAA mandates that AAD's must be used and maintained according to the manufacturer, wouldn't it be nice if they mandate that after an incident, AAD internal data must be sent to them and made public? In the absence of certification standards administered on behalf of the public, the public gets access to more data in order to create more feedback and interaction between designers and users. (I know that's a thought for the ideal world and not the real world of the FAA, who still think a Lap parachute rigging rating is an important distinction.) If one had data, one could see for example if the jumper ended up at what the AAD thought of as height zero (or close to it), putting to rest any fears that the AAD didn't recalibrate itself "to zero" for air pressure changes. I don't seem to recall seeing Cypres data graphs, but a few from Vigil have been published. But isn't the idea that the capacitor is always charged up, so that a higher current discharge is available extremely quickly to fire the cutter? The extra battery thing in the Vigil is sort of a hybrid battery / capacitor. One statement on the web about them: "Pulses Plus™ batteries were developed at Tadiran and introduced into the market few years ago. These batteries combine a primary high-energy bobbin type Li/SOCl2 cell with a hybrid layer capacitor (HLC). The HLC is a battery-like capacitor consisting of lithium intercalation compounds as electrodes with pseudo capacitance of 785F for standard AA size". But what does the Cypres use? From opening up the Cypres 1, there is no big capacitor in there. My photos show only what look like a couple small ones on the circuit board, no more than 1 cm long and 1/2 cm dia. Whatever their design, it normally seems to work. AAD's do tend to have poor feedback about the mode that they are in, what they are thinking. (Although the Vigil does have the flash 3 times thing at activation altitude. Yet it traditionally has also had the problem of thinking it is airborne if driven away from the DZ, now mitigated by the new 14 hr turnoff feature.)

Where I am (Canada) one can buy what look like traditional traps but with a big yellow plastic lever made to look like cheese. They are intended to work without bait at all. Product info says 'no chemicals' but says 'pre baited', so I'm not sure if it is just a visual attraction or there's more to it?! [Of course, plastic is chemicals, as is arguably anything except the basic elements.] The no-bait traps are from the common U.S. Victor brand that have the whole range of traps from traditional to pricy. While fresh bait may work better for all I know, these have always worked fine for me, and are so convenient to set or re-set. The fine folks at Victor also write about some of their other traps: "Using a Q-tip, toothpick or other tool to mask your scent, bait the trap by placing peanut butter or anything high in protein like chocolate or hazelnut spread in the bait trough provided." Sounds like the mice get all the good snack food!

Better than nothing, but maybe someone can find an old manual that has been digitized, that shows main flat packing? The PD manual will have a few gotchas for someone who doesn't already understand packing. Exposing the leading edge, and molaring it for example.

When instructing at a DZ, you have to play by the DZ rules on instruction. I can't speak for every DZ situation but this is as I know it: Want to instruct at all? You tend to have to be on staff or have special arrangements made. (Some big US dropzones are popular destinations in winter and do expect all sorts of visiting jumpers including other DZ staff and students, so their rules may be more open to outside instructors.) Instruction at a DZ is normally under the control of the DZ. If a DZ sets a rate of slot + $15 for a particular type of coaching jump, you can't go sneaking around poaching others' newbies and undercutting them by offering slot + $6. Both the DZ and other instructors might not be happy. Things will be more open if one is coaching licensed jumpers, beyond whatever regular program the DZ offers, especially if it is just an occasional thing. Same goes for other work. If a tandem student would pay $100 for a tandem video, you can't go up to a student and tell him that if he pays you cash, you'll undercut the DZ and cut them out of their take, and do the edit entirely on your own equipment. DZ's will from time to time offer discounts for special cases. (e.g., "You want to take your sister up for a tandem? If you waive your instructor fee, we'll knock off an extra $50 for the occasinal close family member." ) You may not be able to help your friend out much with actual jump costs, but will be able to help him timewise, to learn the ropes faster. (Just avoiding stepping on instructors' toes when it comes to specific things they teach.)

What aspect of the National Post story is liberal, or on the flip side, what is the conservative angle? "Lying about significant events (especially by ex-military people) is ok to boost your image and book sales... because, freedom, terrorists!" The National Post isn't exactly a leftie paper, and it did report the results of the lawsuit, how the second lawsuit against the publishers appears to be carefully done to capitalize on the first lawsuit, and so on. I'm not sure what slant there is in the article and how that corresponds to any basic political philosophy. If they could have added more, it would be more to prove why they think Kyle's claims were false about killing the two robbers or Katrina/Superdome claims (the latter not being in his book). I haven't read up a lot on this so while I'm skeptical of your statement, I honestly don't have enough information yet to be certain of a particular viewpoint. (While I note the irony of a gun nut being killed by another gun nut at a shooting range no less, Kyle clearly was an accomplished soldier. I did enjoy his Sniper book and his book A History of the US in Ten Firearms, to go along books from other authors I've read on the M-16, Glock, and AK series.)

That could use a new thread. Want to start one? (I do use a similar rigging tool much of the time and yes with small modern rigs I find pull forces are often right up at the limit, sometimes taking overnight to settle down. But even with good progressive working of the pack job, such a tool is a big help for the last 1/4" of loop for the last flaps.)

What's up is some not-so-professional photoshopping. Some neighbourhoods to the right of him, sitting on a funny perspective angle, match those to the left of him. Certainly not taken at Nouvel Air near Montreal, despite the logo on the jumpsuit.

The Vigil 2, Cypres 2, and M2 all have a 2 year official warranty. Additionally, Cypres also calls it a Lifetime Warranty for the full life of the unit, in that the maintenance fees are fixed no matter what needs work, and it provides an opportunity to update the software a couple times. (Will Vigil do a free update if you send it in? I don't know the answer. They'll certainly do an inspection and test for a fee.) Both Cypres and Vigil have in general tried to do free replacements in cases where they do have a bad batch, whatever the date. However, as we've seen with the Cypres "stuck on zero" bulletin (#113), if something goes occasionally slightly wrong, they won't instantly take everyone's Cypres in for unscheduled maintenance. And the solution to some other problems (under or over 2 years old) is similarly not a recall but new restrictions in the manual -- e.g., for door opening with a Vigil 2, or watertightness of a Vigil 2. Suck it up. Or some things one just lives with -- e.g., the Cypres 2 cutter cable goes into a harder plastic fitting on the cutter than for the Cypres 1 cutter cable, and thus very occasionally is more subject to damage in certain rigs. As for Argus, their warranty turned out to be, "Oh yeah? Well screw you too! We're outta here." To summarize: Everyone has a 2 year warranty. I figure Cypres maybe treats you a little better because you're already shelling out money for maintenance. But in general, you are trusting the company to do the best it can over the lifetime of your product.

Oh that's a challenge. In other places, that combination (assuming an English speaking instructor) usually results in students being guided gently and carefully to what we call in English, "man-i-fest for tan-dem reg-is-tra-tion" Some good headscratching would be needed to figure out how to work a S/L course with little verbal communication. Interesting for an instructor to think about even for normal courses, as even then, one has to prioritize information, and students need to be able to demonstrate responses to particular commands and particular situations.

Old... As opposed to "Kent Parker Wright", which was used by a Korean news station when a US plane had a landing problem, in humourous retaliation for a US news station making up fake Asian names after the Asiana crash at San Francisco.

Yvanpec: Just to be clear, mcordell is describing the reverse S-fold -- folding the top of the canopy first, getting it controlled by getting it in the bag, then S folding the bottom of the canopy in. This avoids you trying to kneel on a tall, slippery pile with multiple S folds in it.

Interesting. ... with the wind is replacing the relatively cooler air around your body with more and more even hotter air. That's why they have convection ovens!

Looking up the trivia for you: Mighty Mak, Strong Enterprises, 328 sq ft. I recall it being used as a big boy student canopy.

Yeah the brake line only goes through the extra ring higher up, as you suggested in your 2nd scenario. When setting the brakes, one dips the brake line down into the regular ring from the top, and back out the top, with just the brake eye through the ring, and so the toggle can pin it in the regular way. (Sorry the photo just didn't show that part.) So yes the brake line then releases from the main ring, leaving extra slack when front risering. With the little extension for the new ring, there's less friction too in the brakes, as there's less of a bend in the brake line on its way up to the canopy. Accuracy jumpers and swoopers sometimes have had a longer 'third riser' holding the regular ring in the regular place, but with the third riser attached from low down on the rear riser, allowing the line to go through a ring but go almost absolutely straight from toggle to canopy.

When I first tried it, I also found that sometimes the brake line would rub the outside line. So I just sewed on a mini 3rd riser / brake line guide / or whatever one calls it, about 1.5" long. I haven't tried to optimize it in any way; it just fits in place nicely for extra reach and reducing the angle that the brake line makes through the guide ring; has worked fine for a decade. Of course one has to be careful about anyone packing it who isn't familiar with the brake line being outside the normal guide ring. (Edit: On the photo one doesn't see that the brake line comes down from above the main ring and then after being pinned by the toggle goes back out the top.) -- Just a recreational swooper on an FX88. Edit 2: I thought of one downside. If one is sloppy and pops the toggles by yanking them way down and lets them go quickly, the due to the high guide ring right up by the lines, the toggles can flip up and tangle in the lines. I've done that a couple times when pulling near minimums and trying to get down fast by getting out of brakes quickly, and had no time to fiddle with fixing it. So I've landed on one riser and one brake a couple times. If you're gonna be stupid, learn fast...

No issues about rules? Are they just wary of someone (especially one they don't really know) with 90 jumps doing jumps with an extra harness, extra handles, and an experimental parachute? Nice looking container!

Everyone has their owns systems and standards to protect! Can't let someone "get away with" missing one requirement or other by sneaking off to another country. Typically international visitiors get a lot more slack, as most countries licences are FAI recognized and thus broadly similar. There was some rough standardization done a decade or so back,although at the low license levels differences are more likely to significantly affect jumper skills. (But I recall Switzerland is very different than the somewhat standardized A, B, C, D.) But if you're Swiss or live there permanently, then you have to play by their rules. You would likely need to write a Swiss test, to show you know local rules and regs, some of which might be national aviation laws and not just a voluntary sporting body's. That seems fair enough. The trickier bit is experience -- hopefully some of your experience can be recognized, that all sorts of training and coaching jumps still count. If you need to show you've done X, hopefully if X is in your log book and signed by an instructor then you're ok. (Even between the US and Canada that sort of thing is an issue, for example. If a Canadian student gets some coaching down south in the US during the winter, unless those jumps are signed off by a Canadian coach, they don't count towards the licence. That's why Canadian students often meet up with Canadian instructors going south or go to a DZ with a few expatriate Canadian instructors to get signed off.)