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Everything posted by pchapman
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Bob Wright, with 15,734 jumps, may be known to some of you out there from having been on a bunch of the World Record RW formations, through to the Thailand 400 way. (Listed formally as Robert Wright in the record.) He was also a pioneer in Canadian skydiving instruction, being one of the first here to start students on ram-air parachutes (in 1982), and one of the first to do PFF instruction (like the US AFF). I'm sorry I don't know the precise details! He ran a small DZ for 40 years, specializing in PFF, with no tandems at all, and I think was always on as many of the PFF instructional jumps he could. That continued right through this year, at age 73, before his unexpected passing. Bob was my own first jump instructor back in '88. From his obit online:
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Good point. Can't check now but yes PD is one company that has made some estimates on their data panels. Not sure of their source but they aren't dumb either. (And they also deal with not just say tandem reserves, but military tandem reserves, where higher altitudes may be more of a "thing".) Maybe someone has a pic to post.
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As for the side discussion of "how hard are high altitude openings", I'm guessing the answer is somewhere in the middle. So let's not be too harsh on each other. We civilians don't know much about it. Standard references like the USPA say to watch out, but aren't there to provide background evidence. Certainly for standard round parachutes, there's good technical, scientific evidence about much harder openings at high altitudes. True airspeed (for terminal velocity) at 40,000' will be twice what it is at sea level. So there's four times as much energy to dissipate. (Kinetic energy proportional to velocity squared). And maximum opening forces ended up being four times as great too. And for 25,000', maybe somewhat more than twice as hard an opening. The lower air density also provides less restraint to the parachute filling out sideways and thus 'opening' faster. This was all in the US military tests reported in the old, classic Theo Knacke book on aerodynamic decelerators. And probably well verified by modern computer models of parachute openings. BUT THAT DOESN'T FULLY APPLY TO US... We have REEFED parachutes with sliders, and sliders are a well known way to vary the duration of the opening sequence, depending on the speed & pressure of the airflow. The military must have some data out there, but I haven't seen it. SkypilotA1 provides some personal experience -- although I bet his HAHO square parachutes were probably rather unlike our small ZP sport parachutes. So I'm betting "Yes our parachutes will tend to open harder at high altitude so be careful... but not as massively harder as classic round parachute data tells us... but we don't have a lot of good evidence in the civilian world about whether the openings would be tolerably hard or dangerously so." Many of us might have had some opening on a regular jump where the opening was harder and maybe we hadn't slowed down enough from say some small-way freefly, so we kind of have a feeling that extra airspeed can make the G loads less comfortable. (The New Zealand 'discussion paper' - thanks that's interesting. That's on high altitude tandems and provides some graphs of G loading vs opening altitude, but unfortunately they give no source - other than 'US military' - and no info on types of parachutes, whether or how it was tested, or if they were simulations. The graph lines are all perfectly smooth and idealized. They make the point that one has to be ready for both main or reserve openings, and the hard openings skydivers occasionally get, and how those loads may push up against or cross the types of G loads and thus strengths the systems are tested & certified to. HOWEVER, I WON'T TAKE THOSE GRAPHS AT FACE VALUE -- they make it sound like every tandem main canopy opening even at 3000' is 5 G, and every reserve opening at terminal is 8G, with loads of 4000 lb on the harness in the latter case if at say 500lb max load for the tandem. Certainly one has to look at the limits -- like a max weight passenger and a bad, hard, asymmetrical reserve opening. But their graphs seem too pessimistic with no quoted source of what the data really applies to.)
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Everyone ride down? Huh, interesting. Not the way I've seen it done a couple times over the decades. Just contain it out of the way and others jump. Although admittedly if others jump, that is a bit of a, "Screw you you dumbass, you can sit there white-knuckle clutching your damn parachute, we're going jumping like we planned" move.... Or in more detail, keep door closed, contain the parachute, shuffle the guy to the front of the Caravan for example (far from the door), then the guy stays in the plane (plus an instructor if he's a student), others jump. It's not hard to hold on to or sit up against a spring loaded PC or a bagged main, holding it against a wall or bulkhead. Or if it is a C-182, get him to the back corner and the rest could jump. Although there can be variations depending on experience levels, like deciding it is safer just to descend with the full load in the 182, because it is cramped or moving a scared student could be tricky or whatever. Sure one is assuming someone else isn't going to take the tail off on that very same jump run and leave the unfortunate jumper with an even crappier than usual situation! But certainly everyone riding down is a valid thing to do.
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I don't have a good answer, but have some partial ones: 1) The new dropzone.com removed the old photo attachments, so I won't even bother to try to find the original post. But way back in 2012 I copied a post on here by Gabor Szelei. I've put it into a Word file. The descriptions are rather terse so there are still some questions, but that's what I have. 2) And in 2005 I had saved this post, from Sundevil777: Tube stows - Gabor Szelei 2012.docx
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Tension knots and stuck riser in reserve.
pchapman replied to Bluejules8000's topic in General Skydiving Discussions
It does look from the video that there was nothing caught up in the reserve, that it was a tension knot all on its own. A rather unlucky day! (That's both from the start of the video - with you way off in the distance - and near the end where the camera flyer swoops past you on the ground.) Tension knots are made more likely (but still very rare) from a bad body position, or even a momentary entanglement with your foot. (As you said initially, after your massive crash you couldn't recall if it had been the main or reserve that was entangled for a moment around your foot.) Parachutes do better when opening symmetrically, and somewhat less so if one side (eg, jumper's shoulder) starts out way lower than the other. And thus it seems not be have been as I had speculated -- before the photo from the video or the video came out -- that the description sounded like a typical main-reserve entanglement of some sort. Still, it is not impossible that there was some brief interaction / entanglement that hindered the reserve opening, where a very slow extraction from the bag, or interference from a main riser catching lines or whatever, could also have hindered the reserve inflation. In any case, parachutes do open better when they start with a shoulders level body position, everything symmetrical, with no tumbling of the deployment bag, and the deployment proceeds at a normal rapid pace, so that it is less likely for slack lines to be whipping around that are more likely to cause a tension knot. -
While on the rubber band issue, is there any validity in storing them in the freezer? I knew one long time DZO who did that regularly for many years, perhaps only stopping because it is inconvenient to keep a whole freezer drawer full of a bunch of 1lb bags of rubber bands, and Keener bands lasted well anyways. Certainly chemical reactions are generally reduced at lower temperatures, leading to less aging. But I don't know if there is any moisture content within the elastics that might cause damage from water crystallization. One might also want to air them out after unfreezing to dry them from any condensed moisture on the outside. Just wondering how to best store my last remaining big bag of Keener rubber bands, "my preciousss"... For now I just keep them in the basement where they are cooler.
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For the record here it may be worth quoting from Chuting Star, given that Keener Rubber has shut down: From: https://www.chutingstar.com/rubber-bands-for-parachute-packing
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Stupidest thing you've ever done on a skydive...
pchapman replied to RolandForbes's topic in General Skydiving Discussions
Ugh, I had something like that, similar canopy, similar size, back when Sabres -- the first common zero-P canopies in North America -- were new in the early 1990's. "One last really good looking set of turns before heading to the pattern." And the canopy started spiralling. Don't know how it got out of multiple twists so fast but I didn't need to do the low pull-both-handles-simultaneously thing. Those Sabre-class canopies were fast turning, but could snap you into near zero-G, so it was easy to get out of sync when doing snappy toggle turns, unload the lines, and twist up. Others had the same issue -- Saw an experienced jumper do something similar (without the spiral), and some multi-thousand jump Canadian jumper died from low line twists/spiral back in the early Sabre etc era too. It was jump 187 for me, with the added complication of a large early 1990s video camera strapped to my shin with a wide angle lens looking up at the canopy for some maneuvering video. Barely got any video in the end anyways, as the Sony's shake detection mechanism shut down the video tape transport about a second into my line twists. -
A turbulent start to my Cat A - should I call it quits?
pchapman replied to blightybloke's question in Questions and Answers
Another possibility is to do a tandem jump or two. That's a way to get used to going out the door and into freefall, with little anxiety about performance. As long as someone isn't flailing wildly, it'll be easy enough for the instructor to take care of stability and deploy the parachute. Get out, arch, learn to enjoy the experience. Overcoming fear is a big part of the game when starting skydiving; all part of the challenge! -
Looking to buy a used Optimum 126
pchapman replied to farleymartinez's topic in General Skydiving Discussions
I'm no expert on the rules but: A data card is not *required* to be with a reserve. People lose them, don't pass them on to a new owner of the reserve, etc. A rigger might make a personal choice to not pack a reserve that has no known history, but that's not the norm. Under US & Canadian rules etc, the rigger inspects the reserve & decides whether it is airworthy. It would also be very rare for a reserve to have placard info worn away, like what one sometimes sees with older main canopies -- where the serial number is illegible. (That might indeed make a rigger make a personal decision not to pack such a reserve.) -
That is still a valid opinion. I'm still in the old school where the point of skydiving is to have fun, while the new schoolers started not only clamping down on swooping (to avoid all the canopy collision carnage, plus occasional swoop landing carnage), but now are also clamping down on doing anything fun under canopy when up high... I thought or hoped that at least when higher up, people are a little more spread out, so one could have some fun under canopy, even if as people come together in the pattern or LZ, tighter rules need to apply. I personally only have had the rule "don't do anything unpredictable under canopy" when at some multi-airplane formation event with everyone supposed to be on their best behaviour. Anyway, this all does fit with the OP trying to find out what the rules and perceptions are at different DZs.
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Seems a bit harsh. Spiralling is still fun. Spiralling can teach a lot. Doing spirals doesn't mean "simply hold one toggle full down for at least 3 full turns". After all, every swoop starts with some sort of a spiral entry, like brakes & single riser, double risers, harness, etc. Plenty to practice there. Swoop recoveries or emergency recoveries from dives also need a spiral entry. Practicing popped brake scenarios gives you spirals. Testing canopy stability using harness turns while brakes are set, that's another thing that can use spirals. Catching up to another canopy to do proximity (or CRW) canopy work can involve spirals. And, heck, I've done crossbraced swoop canopy 2-stack CRW spirals. (Well, I did that way high up!) Sure, mindless spirals aren't that much fun I guess once one is used to the canopy one is flying, and one is no longer just impressed by the speed of one's newer, smaller canopy. But there are plenty of things to practice that may involve steep diving turns of 180 degrees plus, or maybe 360 degrees, depending on one's personal definition of spiral or partial spirals.
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Sounds a bit like the Canadian PFFI system. When you get a coach or instructional rating, it is in effect provisional, and there is set of requirements to be completed in the next year (extensions possible), with some extended supervision, to fully complete the rating. E.g., Edit: Not saying it has has to be exactly like that, but just throwing the concept out there. I like to think DZ's do just fine in supervising their staff, making common sense decisions about supervision and easing into a job, including AFFI, but this does formalize some of that process.
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From an old manual if you are still unsure. Really, one can stuff the pilot chute in just about anywhere it fits on top of the bag. Mushroom it, or fold it neatly, whatever. Just has to be clear (not jammed in between the bag and container when it is open), and the base has to be near the corner with the pud, so the pud can pull the pin without having to move the pilot chute (so it doesn't jam when the container is closed). Something about not being pretty but it works. Not sure if it grandfathers you to pull at 2k. :-) I used to use a Racer with a pullout.
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Tension knots and stuck riser in reserve.
pchapman replied to Bluejules8000's topic in General Skydiving Discussions
Yeah it is a little hard to piece together what was happening based on imperfect memories after what sounds like a crash landing. A possible scenario: Pilot chute in tow. (Rather than pilot chute around leg, which wouldn't have left you still falling stably while 'nothing happened' for some seconds.) Cutaway & reserve procedures performed. Loss of pressure on main container allows main to come out of container as reserve deploys. Bad luck and bad timing results in a riser from the main tangling in the deploying reserve. Probably nothing to do with tension knots. Just an effectively fucked-up reserve because there's a main parachute somehow connected to it by a main riser caught up in it, pulling at it probably off center or maybe partially choking it off. Leading to a high speed impact under a spiralling, perhaps partially inflated reserve. There are certainly some youtube videos out there of such scenarios. Various related possibilities don't change the basic scenario, just how bad it might be: You might have been thrown into line twists under the reserve; the main could have been partially inflated, mostly streamered, or still caught up in its bag by its lines; the reserve canopy could be fully inflated or have part of it pulled together if the main riser wrapped itself around or through multiple lines or caught under rather than over the slider. -
The actual ad states, "The SST's -- both the standard and the new Racer -- are delivered with ripcords and housings as standard equipment" So there is an "SST Racer", the fancy new model, which I'm guessing just got called / renamed the "Racer" later on. So in casual conversation one could indeed probably call the Racer version of the SST a "Racer SST". It isn't quite the same, but one could describe a Micron container as a Vector III Micron or one of them Micron Vector III's.
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That's fun. Here are the Canadian ones from 1958. I bolded a few interesting ones. Most rules are reasonable for the era. Note you couldn't make a demo jump... on your first jump. =================== 1958 Parachute Club of Canada Basic Safety Regulations Scanned from Canpara, Jan/Feb 1985, which reprinted an early set of regulations. According to PIM 2, the Parachute Club of Canada was formed in 1956. -- Peter Chapman These regulations were Basic (safety) regulations adopted at the Annual meeting of the Parachute Club of Canada, January 2. 1958 at St. Catharines Airport, ON. 1 . Students will not be permitted to make their first parachute jump at a public gathering. 2. No one will be allowed to join the PCC or make a parachute descent while influenced by a bet or dare. 3. Parachutes will not be loaned or rented to unqualified or unknown persons for the purposes of making a parachute descent. 4. No member shall make or attempt to make a parachute descent while under the influence of any drug or intoxicating beverage. 5. No member shall make or attempt to make a parachute descent from the seat of an aircraft wherein is installed a control column or wheel unless said control column or wheel is removed. 6. Training parachute descents shall not be made when the surface wind velocity is in excess of 18 mph (eighteen). These restrictions will not apply when descent is made into water. 7. During training jumps, parachutists must have their equipment and parachute checked by another PCC member. 8. No parachutist shall make or attempt to make a parachute descent without carrying both a main and reserve parachute, on one harness. 9. Clothing, footwear, and headgear for the intended jump must be of a kind and make approved by the PCC. The only exception to this rule being where extenuating circumstances may prohibit use of such equipment 10. Flotation seat must be worn, and a boat in attendance where water is the intended or even possible landing area. 11. No parachutist shall make or attempt to make a parachute descent with equipment which is deemed unserviceable by the PCC for the intended jump. 12. All parachutes, both main and reserve, must be packed by a person considered qualified by the PCC. 13. Parachute descents shall not be made with the use of bat‑wings or similar devices. 14. Parachutists will not descend or plan to descend into an area where such a descent may be deemed to be a public hazard. 15 Parachute descents shall not be made from aircraft in close formation. 16. Hesitators, or similar devices, shall not be used except for specific and premeditated reasons, as well as with the knowledge of the parachutist. 17. Parachutists must not jump with chutes that have not been packed within the previous two months. 18. All parachute descents must be planned to be open by at least 2,000' and that the time to ground to be more than 12 seconds. It is generally recommended that parachute descents be planned with a higher safety factor, more so for the student. 19. No test or experimental type parachute descent is to be made with Club equipment unless authorized by the recognized leader of the group, 20. At all times, the rules of the Department of Transport regarding parachutes and parachute jumping must be strictly adhered to. 21. No student shall be accepted for parachute training and, or jumping unless said student has passed or reached his/her 18th and has not yet passed his, her 36th birthday, except with special qualifications'. 22. Members under 21 years of age will not be permitted to jump without a signed waiver having been received from said members' parent or guardian. 23. Prior to being accepted to parachute training, the applicant must have completed a satisfactory medical examination by Club approved medical examiner.
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Your approach is certainly a rules lawyering one (which can be fun!), and one that may have some debatable merit. Largely looking into whether 'apparent' violations of rules can squeeze into grey areas and not actually be violations of the rules. And thus the whole bit about them not technically asking for 'permission' but just for a waiver of one rule, just in case. FAA rules can be interpreted in many ways! Mind you, have Luke & Red Bull put forward that argument? Did they ever argue that they thought they were OK on the rules but asked the FAA to make it more clear? I don't think people here (with aviation experience) expected the BRS to save the airframe, but it doesn't seem like the plan would have been for the plane to thump in with a still partially reefed parachute. Sounds like Luke and Andy should have drunk a liter of water an hour or two before the flight, then left a pee bottle with their own name on it in the other guy's plane. "Excuse me, I'll just set the plane on autopilot (in speed brake vertical dive mode), and now just gotta fly over to the other plane for a bio break, as allowed by the FAR's."
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What's the saying? "8 hours, drugs to drogue?"
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I'll defer to you on the whole complex issue of health information privacy! But a person (or company?) must be able to do something about information they come across, rather than just being forced to be quiet due to some medical privacy rules. "Hey I know this commercial pilot, I've seen his pill bottles for stuff that isn't allowed on active flight status." or "I saw this tandem instructor smoking pot before jumping today -- can we ground him for the rest of the day?" That's probably all I can contribute to the questions in this thread.
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Sounds reasonable.... Unless the USPA specifically has some procedure in place where they say that all FAA records are subject to USPA review and acceptance, or they have some mechanism to charge that a USPA member has falsified the information used to obtain the legal document. (Hey, anyone can challenge the basis of a document. After all, some organization could say, "Mr. X has gained US citizenship, but we evidence suggesting he failed to tell immigration that he had been a member of a military unit in his homeland, that was involved in war crimes. This may invalidate his citizenship application." One can't respond to that simply by saying, "Yeah but his citizenship is correct according to the government." Of course one has to differentiate between disputing the actual certification (citizenship) and whether a particular organization will accept it.) So in my mind things could go either way, depending on whether the USPA properly followed their own procedures. That's where one would want to see if they need to be held accountable.
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All the stuff the FAA has jurisdiction over! Plus one of the articles stated, just to rub it in: Pocket change for Red Bull, if they're still on board with the "gee I forgot to tell the team about the FAA denial" thing. Cool stunt though.
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That reminds me about trying to sell a Vector II for a friend, maybe 20 years back, that had had a few owners over the years. When I checked the size code listed on the rig, it just didn't exist in the manual. And when I checked the serial number, it said "BOBBY". Hmm. I got the impression it was a rig that some trusted production line guy was allowed to assemble for himself.