pchapman

Let me try to be clearer about the PIA study: They do indeed say to fly the front canopy with brakes unstowed, but never say WHY they conclude that. They never mention even trying to fly it with brakes stowed. They never claim any data from their test jumps to support the conclusion. That's different than in the case of the rear canopy, where they report on trying it both ways, and from that data, come up with a conclusion.

Thanks for posting the PIA dual square report here. The report does say to leave the brakes set on the rear canopy of a biplane, and they back that up with statements about tests where for most but not all canopy combinations, they flew better with the rear canopy in brakes. But for the front canopy, they suggest flying that in toggles, yet don't provide data or statements to back that up. They don't specifically mention flying the front canopy with the brakes in hand versus with the brakes set. So the PIA study unfortunately doesn't provide any evidence about what to do with the front canopy, but seems to just assume that one would fly it with brakes unstowed. (As for whether to flare or not for landing, they say not to flare, but say that part of the reason is that students may flare too high. We always have to distinguish between what the 'ideal' action is, that we as experienced jumpers may choose to do, versus the 'simplified' action that may be best to teach students.)

If you are doing tandems to have fun... then have fun and enjoy the sky. If you are doing tandems to get ready for solos... then I hope you are or will make sure that the instructor challenges you by having you make more & more of the decisions. He'll be along for the ride (maybe assisting with toggles) while the pressure is on you to choose the pattern and fly it. Work out the anxieties and questions about how to do things, with an instructor there with you.

I see that there can be some negative transfer, that shouldn't be ignored -- but I think the positive will generally outweigh the negative. The worst negative probably would happen with paragliding vs. skydiving because the controls are similar -- you aren't going to get much muscle memory transfer, good or bad, from going from an airplane control yoke to parachute toggles. Certainly one may have misconceptions about parachute canopy flight if coming from paragliding, but there are so many misconceptions anyway about parachute flight, that it comes down to training. So I have heard of pilots falling way short on final when they try to fly the circuit with a parachute, but once they clue in to the visuals of a low glide ratio and poor wind penetration, I bet they can figure out the whole circuit idea pretty fast. (If we take this any further, it would be best to take it to a new thread.)

For reference, the SIM says: FWIW, the CSPA says to leave the brakes stowed. I'm interested in the whole question too, although my current thoughts are to usually leave the brakes on the front canopy stowed. The answer for me would vary if I think one canopy is a lot faster than another -- e.g., Fast main infront of slow reserve, keep brakes set. But if fast main behind slow reserve, maybe pop the front canopy's brakes.

I found my photo of a side by side comparison of a PC Mk1 in a bag vs. a Parafoil 282, to help get an idea of the sizing. (I don't know where the PC bag came from, but from its size I figure it had been used when students still jumped PCs in the early 80s. I don't use the split flap closed by velcro, just like most people didn't use the split flap on Vector II d-bags.)

I appreciate their sacrifice for others' freedom. Or alternatively, damn them for trying to destroy others' freedom by screwing up. The high wing loading made things worse for them but that wasn't the sole cause. Making bad off-landing choices and starting to swoop without a proper progression did it for them. As for my progression: My downsizing to try out small canopies was reasonable in an old school way: After about 190 jumps on big F-111 canopies, I took a dozen jumps total on 3 progressively smaller sizes of ZP canopies, before I started flying a Jonathan 92 at 1.8 loading for a few jumps. Although running out the landings wasn't always pretty, even on a hot no-wind summer day I could handle it. I wouldn't want to have such an experience taken away from me because of someone else screwing up and causing simplistic wing loading requirements to be put in place. I don't want to inflict those kinds of rules on today's newbies just because it won't affect me with plenty of jumps now. Flying the little canopy wasn't that big a deal because they were high hop and pops, not deploying low after RW, not mixing it up with other traffic, not taking it to Eloy on holiday. Nor was I trying to crank hook turns on it, I wasn't flying it every day in all conditions, and the total risk (as opposed to the per jump risk) was low due to limited number of jumps I was making on the canopy. Plus I was already a pilot and aerospace engineer with some understanding of flight and risk. None of those factors are taken into account by simplistic blanket wing loading restrictions. (I might agree to some wing loading restrictions as long as one had the ability to get local experienced jumpers provide waivers.) As for the canopy types that I regularly flew, the progression really had few steps in it: I owned a big F-111 accuracy canopy for years, then a Sabre 135, then an FX 88 (at 1.9 WL). While I had tried the FX at jump 550, I didn't buy it until jump 775. At that time I had only about 90 jumps on zero-P of 1.2 wing loading or more. Going from flying accuracy plus occasional Sabre 135 or Stiletto 120 jumps, right to a sub 100 crossbraced, was clearly a bit sudden. That sort of sudden progression certainly made it harder for me to learn to swoop well. If that's one's goal, then the canopy choice was poor. But what's to say that the only goal possible in skydiving is to swoop competitively? The tempation to swoop too hard too soon is so much greater now, with it being so common and seen as the cool thing. Today we benefit from having more canopies that provide a stepping stone towards small crossbraced canopies, like Katanas and Crossfires. Although I have been quite harsh about resisting wing loading rules, I am saying all this as someone who has run canopy control courses and does care about teaching newer jumpers to fly safely and make knowledgeable choices.

Nice to see someone give the guy a straight answer. It is possible to treat skydiving knowledge as other than a secret, while not actually screwing up a novice's progression. Skratch didn't go into the kind of detail that would have the newbie practicing things incorrectly in his living room. @ the original poster: If there is any little unevenness or twist in one's body position, that starts a turn going, as air is deflected more in one direction than another, glancing off one's torso or arms or legs. That's no big deal if one knows how to remove that twist or counter it with one's arms and legs, but if not, the novice may just keep spinning and not be able to stop it. One might say that it is a "riding a bicycle" kind of thing -- Impossible to control before you 'get it', and then after that, really quite easy.

Thanks for posting the video for others to learn from, and then owning up to it all.

Ok, so it's a gabled roof on a 2 story home. That's a bit sportier than a flat industrial roof! TWO OUT: The vid is a good example of how one's options are limited if one isn't at a DZ surrounded by fields. He has the dilemma of how much to maneuver with a two out -- something he had to do if he wanted to actively go for the couple open back yards on the near side of the street rather than just taking whatever came up when flying straight. Or there were the yards open to the right of the house he went for. I thought he could still have made a 90 right when crossing the street to go for those yards at the last minute -- but I see there's a flagpole that he'd have to miss. Spotting the obstacles is a fun game here! For a moment it looks like he's going for the gap between the house and trees along the driveway -- but there one can see power lines crossing to the house. Houses have electricity, and unless you are in a modern subdivision with buried utilities, there are going to be power lines somewhere... It's a good video to save to show newer jumpers to ask, "What would you do if you were in this situation...". He's very lucky that last moment turn he made didn't put him legs first straight into the chimney. PULL ALTITUDE: Even after getting out of backfly, he keeps looking up at his friend, and finally has a good look at his alti, at 16 sec. While at first glance the alti looks like it is around 2k, if one takes an older Alti III (red to 2.5k, yellow to 3k) and puts it at the same angle with parallax, I think the needle is showing more like 1.6k - 1.7k. Other evidence of that sort of basement altitude is that when the alti flashed by in view at 10 sec, it looked like about 2.5k. So no wonder that the alti is showing something in the 800 ft range (plus or minus a fair bit since it is fuzzy) when the reserve is starting to deploy above him. (And the alti looked more or less correctly zeroed, from views on the ground.) Maybe that's a bit higher than he expected the Vigil to fire, but we all know about the error that one can get from the burble going from belly to standup. All this is just a complex way of saying he was not aware of his altitude and pulled low. It is funny that he automatically stows the main slider, but at least he catches himself from popping the brakes.

If the race car analogy is to be used, my opinion is that one should expand it: There is a difference between just trying out the race car a few times, and driving it all the time, or actually driving it in a race. There's much less risk to jumping something small (especially in the risk to others) if it is away from other canopies, and one is flying in not too aggressive a manner. I like sticking up for the concept of being able to try out different parachutes without all sorts of arbitrary limits -- whether or not it is the proper parachute to be using for one's day to day jumps or for progressing to swooping competition.

Minor update to this thread I started a month and a half ago: A friend had one of the Vigils that was having a problem, shutting itself off. He exchanged it for a new one -- Vigil USA did indeed get the new one to him quickly and with no fuss. (The Vigil manual does mention a 24 month warranty.) This past weekend, the new Vigil was up to the same old tricks: Sometimes it turned on OK, other times it turned on, said "Hello", and then shut off (with no error message shown). That suggests that either: a) the controller software problem (that came to light due to this thread) is not confined to only the units Vigil believed it to be, or b) the problem has another origin, of undetermined rarity. The unit will of course be sent back to be looked at.

One of my PC's is in a d-bag. Volume wise it is much bigger than a Parafoil 282, which is quite bulky and bigger than an equivalent student canopy of that square footage. So even old student or accuracy gear might not be big enough. The technique I used was to build a simple "main container" that velcros around the existing main container but is bigger. It has 3 flaps, and uses the existing main top flap / pin cover flap. The original flaps just tuck underneath. I learned this from some Aussie accuracy jumpers. I think I've posted pics somewhere on dz.com at some time a few years back. They could use their regular small rigs for Style, then velcro on a big main container for Accuracy. The only other complication I can think of is what to do with the crown lines. They should be stowed to meter out neatly. Or at least that's what people tell me. Option 1: I put elastic stows inside the top of the bag, to stow the crown lines just like one would stow parachute lines in general, zig zagged back and forth. Stow before folding the canopy into the bag. Option 2: Others have put the stows on the outside top of the bag, and have the lines pull through a large (but smooth and undented) grommet in the top of the bag on opening. That's been mentioned in old threads on deploying PCs'. I'm not sure how the bridle attachment is then done, but I guess it could be sewn to the bag, leaving the grommet clear for the crown lines only.

Since you mention M2 Distributions (Incorporated!) a bunch of times, who are they? Are they part of Mars, or an subsidiary of Alti-2, or a separate company or what? Owned by whom? And whose website will we look at eventually?

Agreed. They would add any twist but if the instructions weren't really detailed and the rigger not thinking of the issue it could happen. But it is different. Instead of folding two sides to the centreline (touching there), like National or Strong, they fold the two sides only partway in, so it looks like there are 3 equal sections. But, they don't describe the process. They only say "fold the canopy lengthwise into thirds". Only by squinting at the pdf image can one barely see what is being done. The clue is that the canopy is too wide compared to if one folded the two sides overlapping, which could also be interpreted as thirds, having three equal sections stacked. The rest of the procedure is better explained. One gets it folded to "fifths", although then some fabric is spread back out to give the width they desire. Strong describes their procedure and also calls it "fifths", but it folds the canopy in a different way, resulting in a different fold configuration. (Sides to the center touching, then inwards overlapping.) National uses the same technique as Strong but doesn't use the "fifths" term.

Now you could be talking both about folded down towards the backpad if the reserve folds pile up on each other, or folded down away from the yoke if packed in folds up towards the yoke. I'll defer to councilman24 but I had the impression that folding the apex down was to keep the mess of lines at the apex from being able to catch on anything. Keep it away from the flaps, or maybe a pilot chute that was burrowing its way into the pack job (in early rigs with no flap, only a kicker plate), who knows. Just another theory. Folding the apex under doesn't really create much of a twist -- after all, its just a short fold and will pull itself straight in a very short distance. Or are we thinking about different things? With rounds one does have to think carefully whenever there's a 90 degree corner to be turned, so that one doesn't keep adding 90 degree twists. Or one can do do those fancy corners, sort of zig zagging, that avoid any twist at all, keeping the same side of the canopy facing the rigger throughout the pack job. (Obviously follow the manual, but it helps to understand the principles behind twists and turning corners.) Line equalization diapers For some rigs, like Strongs, if using normal rubber bands, one double wrapped the 2 or 3 locking stows on the diaper -- trying to make sure those stows stay locked until all the stows in the pack tray come out. Guess it works -- it did for me last month on a Strong. You still have a point that it sometimes seems odd how the to-the-diaper-stows lines and the direct-to-the-canopy lines will pop out of the pack tray elastics together all the time. (Funny how people wonder if double wrapping locking stows on a bag can cause a bag lock. Well, I hope double wrapping isn't hazardous, as they do it on reserve diapers! Mind you one is careful about bight length, so none should loop over each other as tends to be the case when d-bags get locked closed.) A round issue of my own - folding terminology I disliked those simple old manuals that said something like, "Fold the canopy into fifths" without explaining what that meant -- presumably everyone knew back than. But actually, terms weren't standardized: Strong describes folding the flaked canopy, sides in to the middle, then another set of folds inward and overlapping. This is called folding into fifths. That's the standard fifths as I know it. But ParaPhernalia does the fold differently, yet they also call it "fifths". They fold inward but not to the centre, creating 3 equal parts. Then the sides are folded to the centre. Similarly, when folding the skirt up so that it lies parallel to the radial seams, ParaPhernalia calls it a 45 degree fold (as the fold line is on a 45), while Strong calls it a 90 degree fold (as the edge that one is moving, changes orientation by 90 degrees). All that did confuse me when looking at ParaPhernalia manuals, trying to make out how the photos didn't seem to match what the text was telling me, based on my previous Strong experience. So even basic round canopy folding terminology was never standardized. Argh! (Or is ParaPhernalia is the odd one out??) We knew that in packing rounds that the top end of the canopy gets only folded as much as possible, which is basically not at all by the very top. But it would be confusing for a new rigger, as manuals never mention doing anything different at the top than the bottom. When dealing with the thick and lumpy upper lateral band area, or the few feet just below it, folding "into fifths" is about as doable as folding a major city's telephone book.

Pull left! Pull right! Must have been that short period of time when companies hadn't yet standardized.

I knew someone who was jumping a Sabre 1 107 at 1.9 wing loading at 350 jumps. That doesn't say much about the canopy overall, but shows it could be landed quite successfully at loadings well above recommended.

Good point! While odd to make acronyms out of parts of words, and not full words, we can find some other precedents. We do the same with dropzone, DZ, vs. drop zone. We use the two words as one single concept, and some or many of us turn it into one word. Deoxyribonucleic Acid becomes DNA not DA, but chemical names aren't mainstream words. Airport Rescue and Firefighting in NTSB reports becomes ARFF not ARF. That's all I can think of off the top of my head. But it shows there isn't just one simple rule used all the time for making acronyms.

I'm guessing we shouldn't take the idea too far either. While I haven't checked to see specifically what the research showed, not everyone is going to be overconfident about what they don't know. There are plenty of times where you know your are no good at something -- unskilled and aware of it. Even if you feel some sense of accomplishment at a small success in the field, you know not to overinflate it's meaning in the big picture. In teaching skydiving we deal both with overconfidence, and underconfidence.

Ah, the "unskilled and unaware of it" cognitive bias. Demonstrated in skydiving by some of the Mad Skillz crowd.

I was lucky not to be indoctrinated as a kid. I went to church Christmas & Easter with my mom. While pleasant, it was more a social / cultural / tradition thing. I read bits of the tiny bible they (who?) handed out at school. Nothing was ever said against the existence of God, but God was never talked about either. So I was able to come to my own understanding of God, and it all just seemed so silly. There seemed to be no scientific need for God, nothing happening in the world where it looked like believing in God helped. The Christians had these bizarre ancient tales in some book that they keep arguing about and trying to understand. It seemed a bit of a scam, churches and kings telling people what to do in this life so they'd be better off in some later life that seems unprovable one way or another. The organized churches really ruin the whole God thing. Catholicism has been mired in the dark ages when adjusting to modern society, and so many wars have been fought in the name of some God or other -- including some sect of Christians against another sect of Christians. Another clincher for me was wondering why I should have been born one of the chosen ones. Yes I was lucky enough to be born in a stable first world democracy. But if there is a God, and just about every society has had a God, why was the locally favoured God (the Christian one) the only correct God, the one true God, and everyone else was going to hell? So all those people of other religions are inferior? Most people don't pick a religion because they've compared them and prefer one religion's value system. Physics wouldn't get far if people just believed the science their local ancestors believed. It did take me a long time to give religion a little credit, in that in times of weakness and suffering and death, it is very convenient to believe in a god and something higher than oneself. It can be psychologically comforting, as humans can't deal with such things very well. But what you believe in when you are out of your mind with grief or on your deathbed isn't a good test of what you should believe in. What Ron said in defence of religion works just as well against religion -- we have a strange sort of agreement there: One can use God as a psychological crutch if that's useful, but that's no reason to truly believe in such a magical being, nor all the crap that's unfortunately associated with religion.

Hey Parawing, I see you are new to the forums. Welcome, and get your ass over to the History & Trivia forum! That's the place to be to reminisce, and to join in conversations about old time jumping and jump gear. Some of us not-yet-old-timers hang out there to learn more about the old days. And there are those of us who are into jumping old stuff too. (Hell I chopped with R-3's just last month. Less snaggy but I still tried to cover them during the belly reserve pull.)

Isn't jumping to raise money for charity something that is done semi regularly in the UK? Googling that comes up will all sorts of UK links. One site for example says, "UK Parachuting work with over forty sponsored Charities in the UK and around the world." and the site includes links to select one of many charities and book a jump right from the web page. It's odd to me because it isn't organized as a regular thing in the US/Can. I seem to recall a small controversy some years back, when there was an inquest into an accident by a first timer doing a charity jump. It was asked whether the accident person, or some people in general, might be overly pressured into jumping when it is 'for charity'. But that's really no different than people being pressured into jumping with their buddies on any first jump course. Then of course you get into the issue of whether one could just raise the funds directly and send them to a charity instead of 'wasting' a huge percentage on the jump activity. That is, spend money on jumping if you want to jump, and spend money directly on charity if you want to support a charity.

A minor point perhaps: If you are a CSPA member, your CSPA 3rd party liability insurance will only cover you when jumping internationally at FAI associatied DZs. That is, at a USPA DZ in the US, but not at Lodi.