pchapman

Yeah, it's common for jumpers not to be enthusiastic about anything older than what was still seen on the DZ when they started. Jumpers are naturally wary of stuff they aren't familiar with or can't easily learn about from their colleagues. If one 'grew up' with a certain type of gear, one is likely comfortable with the level of risk associated with it. Same goes for riggers.

Speaking up for foreigners: Some allowance for "lies" can be made for non-United States residents, as their credentials might not fit with the categories available, and even when they are honest, they choose the nearest reasonable equivalents.

Pioneer Titan 265 in a Racer. It has accuracy modifications to it, like soft cells (bottom surface vents), and shortened lines. It also has experimental upper surface slots, across the whole canopy, facing rearward, above the B lines. I'm not sure how that mod affects flight characteristics, but it makes for an awful lot of holes. It's good for accuracy, because the crappy flare makes one want to hit the peas. It served as my main canopy for 400+ jumps from '91 to '02, and I still use it as my second rig. Despite its slow nature, old F-111 like that is great for some things: -- trashing. People have looked up and thought they were seeing a mal, then realized that it was 'just me'. -- toggle hook turns under 100' -- taking to Bridge Day (Actually that's another Titan I have, less baffed, with a tail pocket I put on.) -- low RW. (Not low like 1970s craziness, but just nice little 3 ways from 3 grand on bad weather days, the sort of thing you don't want to do with sub-100 ft ZP wings.)

Guess that is the only reg. It was staring me in the face -- I had it in my original post. It is sometimes good to 'go back to first principles', or in this case, the federal regs, to understand an issue. As for looking for loopholes, yeah, I would. I'm no fan of the reg. I'll save that discussion mostly for another time. Just one sarcastic comment for now (NOT directed at those who helped out with responses to my question!): Be careful you don't get your rigger's ticket pulled because you leave a customer's rig in non environmentally controlled room. The manual for one modern & very solidly built reserve says that "When the parachute is not used it must be stored in a room where the temperature is kept between 15 and 30 [degrees C]. And where the humidity is between 15% and 70%." Remember, riggers must comply! Over and out.

Thanks for the info. There are stilll some issues in my mind though. Ah, FAR 105 not AC 105. So AAD's are a special case, specifically mentioned. Regarding following manufacturer's instructions: But that doesn't say the rigger has to follow manufacturers' instructions... just to UNDERSTAND them. Is there some other definition or rule that clarifies or adds to that? If we can't find any other rule to quote, one would have to conclude that all those arguments about following manufacturers' instructions go out the window. The exception is cases like AADs that have specific rules in the FARs. Interesting to know, but that refers to taking rigging tests, and not rigging in general.

I'm trying to understand some of the US Federal Air Regs pertaining to skydiving and rigging. Just which regulation in the USA requires riggers to follow manufacturers instructions? This requirement is often at the heart of discussions about Cypres maintenance, repacking old reserves, and following instruction manuals. I see that FAR 65.129 (e) says that "No certificated parachute rigger may-- […] (e) Pack, maintain, or alter a parachute in any manner that deviates from procedures approved by the Administrator or the manufacturer of the parachute; " Is that the regulation that is referred to so often, such as when people discuss why a rigger isn't allowed to repack a reserve with an expired Cypres battery? Or is there another reg that also applies? The term "parachute" in the quote must refer to the whole 'approved system' -- but where is that definition? (I know the main chute is not included in the requirements, as stated in FAR 65.125 (c)) And in the case of Cypres batteries etc, what rule makes the AAD part of the approved system? AC 105 on parachuting mentions that "The FAA does not approve AAD's. They do approve the installation which is submitted with the manufacturer's TSO paperwork." So that doesn't address the battery issue.

Interesting scientific research humour along the lines of the Journal of Irreproduceable Results or Annals of Improbable Research!

The Aussie parachuting federation has a nice little freefly manual. I haven't looked at it lately so can't critique it well. As I remember had some decent content for beginners. Free online along with all the other documents they offer at: http://www.apf.asn.au/apf_services/publications.asp

In the vein of interesting-old-stuff rather than what-should-a-newbie-buy: My first main was a ParaFlite Titan, 265 sq. ft of F-111. Still jump it from time to time in my 'spare old rig'. And I've got another Titan set up for Bridge Day BASE trips in the same container. The kids today just can't do that sort of thing with their gear.

If I may post someone else's work, the following is a very informative posting from the PIA riggers bulletin board and covers all sorts of ring & riser combinations. Most pertinant to the current question is the bit about how recent mini risers (with mini rings) are not as compatible with large harness rings as the earlier (but sometimes weaker) mini risers (with mini rings). ====================== 3-ring question - (tk@relativeworkshop.com) 07-25-02 Can risers with mini 3-rings be used with a harness/container with a standard size ring? In most cases, the combination will work just fine. But you have to understand that there are many different types of harness rings and a plethora of manufacturers producing mini 3-Ring risers, and they're not all making them the same! And what is a “standard size ring” anyway? I can only speak for Relative Workshop and the products we produce. Here is a response I sent to one of our dealers recently that covers this topic. Relative Workshop’s Type 8 & Type 17 "mini-ring risers" are compatible with most other H/C systems using large harness rings that are currently available. They were designed that way many years ago. During our many test jumps, when we carry three (3) canopies, the first two canopies are mounted on mini-ring Type 17 risers and connected to the same large harness ring. (Either the 5010 ring or the RW-1 harness ring) In other words, two (2) risers per ring. We've experienced no problems with this set-up over the years. Here's a short list of large harness rings that are compatible with T-8 & T-17 mini-ring risers, followed by a list of mini harness rings that are also known to be compatible. Compatible Large Harness Rings: 5010 Ring (round ring-original circa 1975); RW-1 (slotted ring-original); and the RW-10 (slotted ring-stronger version), and similar variants produced by foreign manufacturers. Compatible Small Harness Rings: RW-5, RW-7, RW-8, RW-8S (Stainless), and similar variants produced by foreign manufacturers. Note: RW-5 and RW-7 were discontinued for several reasons: 1) The cross-section was very small, increasing the possibility of "knife-edge" damage to the riser's webbing. 2) As Spectra (Microline) became more popular, increased shock-load transmission to the riser would eventually result in ring deformation, so the cross-section thickness and overall strength was enlarged. Hence the evolution of the RW-8 slotted ring. In early 1998, Relative Workshop conducted a six month evaluation of the 3-Ring Release System. The results of those tests lead to a change in riser construction specifications that culminated in the latest specs that we've been using since August 1998. We produce a manual that is available to other manufacturers of risers so they to can make use of the latest riser technology. A bad combination is the post 1998 spec Type-8 mini-ring riser with the Rw-10 ring, as this cuts down the mechanical arm. Mini risers built to pre-1998 specs are compatible with the RW-10 ring because there is enough room between the rings so the mechanical leverage is not hampered. But those risers should be grounded due to their lighter load capacity, especially when used with a Spectra lined canopy. (Many have failed in actual use during the mid 90's) They fail at 2500 lbs. The latest spec Type 17 riser will now fail at 3500-3700 lbs. The large harness ring that is known to be "incompatible" is the RW-9. This ring is often referred to as the "Canadian Ring" as it was first known to be used on rigs built for the Canadian military. The cross-section of this ring is very large, which causes the incompatibility. The RW-9's most unique characteristic, other than its size, is the flat surface at the top of the ring (the part that comes in contact with the riser) This flat edge allows for more even loading across the surface of the riser's webbing, also enhancing the riser's ability to handle heavier loads with less resultant damage. Information submitted by T.K. DONLE, Relative Workshop, Deland, Florida, USA (RWS/Bill Booth, designer & patent holder of the 3-Ring Release System)

Winsor replyin to murps2000: If the jumper hangs out under canopy, they're being blown downwind and will have the same horizontal separation as in freefall. Even at opening altitude the jumper is at the mercy of the wind, and their motion with regard to the ground is irrelevant. BEHAVIOUR AFTER OPENING: While generally I'll trust Winsor, there's a detail to be careful of here-- When murps mentions "hanging out under canopy" I think he doesn't mean someone circling around gently, drifing with the wind, but someone faced into the wind, staying over the same point on the ground. Maybe that's because the jumper is doing their wind checks, or just wants to make sure he doesn't get drifted too far downwind. It seems to me that the assumption of what the jumpers do after opening isn't always made explicit or emphasized enough in these separation discussions! When first thinking through the physics, it is simplest to think of jumpers drifting under unsteerable round chutes. An exit separation that's good enough for them may not be when adding in the unpredictable flying of parachutists at 25-45 mph under canopy. Some jumpers might tend to stay in one spot over the ground, therefore reducing the separation from the next group. On the other hand, fast canopy pilots who are less concerned about the wind, may make a beeline back downwind to the DZ. This will increase separation from the next group. This suggests that in the case of a load with a lot of groups being dropped, longer separation is more important for the first groups dropped. Someone who was in one of the early groups to drop is more likely to have the previous group flying upwind to make it back to the DZ. The last few groups out of the plane may be safer, all else being equal, as each previous group will be more likely to turn to fly downwind after opening. All this assumes 'normal' wind conditions, not some strange 180 degree wind shift between jumprun and opening. (This issue has been about a jumper under canopy endangering the NEXT group to have jumped. Normally nobody under canopy can endanger anyone in a PREVIOUS group. One exception is the head downer after a flat RW guy. The head downer opens first despite leaving the airplane later, and immediately flies downwind along the jump run, rushing towards the point where the flat RW guy is about to deploy. ) I'm not usually at a big-aircraft DZ, so I don't know what people usually get told at such DZ's (or boogies). If one is the person in one's group who happened to track upwind, it might be best to turn back downwind once open. Still, as the exit separation may only be a matter of 5 seconds, that's not a lot of time for the person under canopy to do much. It's probably better to rely on longer exit time separtion, than on evasive canopy maneuvering for safety... As for many skydivers not understanding the basic physics, that's true. But even for those of us who like to think (correctly or not) that we can get our head around the issue, some rules of thumb and simplifications for different situations are helpful so that we don't have to work out the equations while on jumprun.

When looking at a list of Classifieds there is a column for the price. But when one clicks on a particular ad to bring up a window with all the details, the price is no longer shown. (Unless the seller happened to write it in again.) So the critical information gets split between two different windows; it is never all in one place. Very awkward when looking at and comparing multiple ads. Therefore I'd suggest that if there's time & ability to modifiy the code, to repeat the price display in the window used for the details of the ad.

Bottom closing loop below the canopy instead of between the ears: The Racer manual online does say that a Racer can be packed either way, as desired according to space available. Even without a Cypres box lump in there, I pack one of my Racers with the loop below the canopy. The reserve gets 'dogboned' in shape, but that's something even other manufacturers have recommended for small rigs with a Cypres. With the canopy well prepared like that, I figure the loop doesn't have to drag across the canopy to force it into position. (And there are also the little webbing tabs inside the bag to protect the canopy from the loops. Haven't seen a newer Racer freebag to see whether they're still used.)

OK, there are always some riggers around saying that Racers aren't that hard to pack if you know the tricks... but I rarely see any tricks mentioned So I'd like to know of some, if any riggers out there don't feel they're giving away their hard earned competitive advantage. (As with many things in life, plenty of practice and experience will also make the job much easier, beyond the 'book learning'.) I can get by packing Racers, but it still seems an endless repetition of bodkin in, bodkin out, bodkin in,... Peter Chapman (own a Racer with a round and one with a square reserve)

Regarding Canadians wanting to jump in the USA: I've used CAA. But be careful: In the last year or two I've seen a brochure that excludes skydiving, but when I phoned and asked them about it, they said skydiving is OK, and faxed me a different version of their exclusions! I've also used www.travelunderwriters.com 1800 663-5389 For me the price was better for a longer trip, but for very short trips their minimum charge is higher than CAA. Their insurance features may be poorer than that of the CAA, but I'm not sure on that point. February 2003 info from the CSPA chat list: Others wrote that companies that cover jumping include: -- RBC (aka Voyager) -- TIC -- Belair Direct -- IMG Patriot (thru Worldtravelcenter.com) -- Skydiving OK if purchase optional rider -- Blue Cross now covers recreational skydiving again Never tried these, so they're just leads to check. BUT, might some companies not offer services for Quebec residences? (Because they don't have a full bilingual setup?) Insurance is one of those things that differs from jurisdiction to jurisdiction. Peter Chapman Toronto, Ontario

Thanks for the info everyone! MDS is indeed another plastic I've seen on rigs in general. As for Nylatron, I've used it in a non-skydiving application. In that case it was an oil-impregnated greenish nylon. It could be that under the Nylatron brand name there's also a greyish MDS-impregnated type. While I don't have enough experience to know for sure, I still think not ALL secondary riser covers use ballistic nylon. I've felt some covers that felt heavier but more flexible than most, which would make sense if they used ballistic nylon. Yet others still have a 'crinkle' to them, as if there's a thin sheet of plastic in there.

Any idea what kind of plastic sheet is used inside the secondary riser covers found on modern rigs? I'm guessing something like 0.020" UHMW polyethylene. Or slightly thicker for more stiffness. Lexan (polycarbonate) is a possibility but I think it is more likely to crack.

Unless there was another incident I didn't hear about, it was a powered paraglider pilot. Many newspapers, though, couldn't tell the difference and called him a parachutist. Off the top of my head, there have been at least one, maybe two such pilots who liked landing where they weren't supposed to. One was known as the Fan Man. And one landed in the grounds of Buckingham Palace, something like that. And one got tangled up on the Statue of Liberty I think. Whether it was all the same guy I'm not sure. That's an overview; I'll let someone else worry about the details.

Quade wrote: That I'm not so sure about. The assertations remain to be supported by further evidence. Your reply doesn't really add much to support your case; while I don't have any good evidence except anecdotal. The math: Slight mistake in the math? I believe you meant that a doubling of the speed would cause a roughly four times (not 10 times) increase in the force applied at the tail. OK, fair enough. But aren't counteracting forces also going to increase with the square of the speed? (Like the negative pitching moment of a wing) Mushiness: Yes, the control feel will be different at different speeds. And that in practice does affect how much or how abruptly pilots handle the controls. A pilot may inadvertently pull the stick back too much if it only takes 4 lbs at low speed, rather than 40 lbs at high speed. But doesn’t affect my argument one way or another about stick position. IN ANY CASE: I'd still like to see jumpers' reports on whether they can stall (or reach the edge of a stall with) their canopy in higher-g flight, and whether the toggle position varies greatly from that during a normal stall in a straight glide. That's in line with what was asked at the very beginning of the whole thread Not sure how to safely collect the data though. Stalls while in diving spirals don't sound like too much fun, even though I'm more prone to trashing canopies than most people.

If we agree with this, and I do, then we have answered WHETHER a canopy will stall at a speed higher than the 'regular' stall speed (achieved through slow deceleration to a stall). The next question is also vital to the canopy pilot: WHEN will the canopy high speed stall. In particular, what interests me is whether the toggle position (or rear riser position) will be different for a high speed stall compared to a regular stall. In aircraft, stick position is typically fairly well correlated with angle of attack: E.g., haul the stick back 6" and the plane will keep flying, haul it back 8" and it'll stall / spin / snap whether in slow flight or higher speed flight. So if you need a certain amount of brake to stall your canopy in normal flight, won't you need about the same amount when in a diving turn, trying to dig out of the corner? If that's true, then high speed stalls can theoretically be avoided by simply knowing where the stall point on the brakes (or rear risers) normally is. In practice there will of course be the tendency to pull too much brake when trying to avoid the ground. Peter Chapman

One transparent paraglider canopy was built: (So packing and opening shock are not issues.) http://www.expandingknowledge.com/Jerome/PG/Strange/Image/WING_Transparent_VL_1994_11_p10.jpg The short description about it is on the next higher level page: http://www.expandingknowledge.com/Jerome/PG/Strange/Album.htm (Search for "transparent".) The site is a fascinating one for anyone interested in ram air technology, although the site is for paragliding and not skydiving ram airs. Peter Chapman Paraglider pilot too

FWIW, I know a biplane paraglider has been built. A fun experiment, but it didn't lead to anything. Believe it was by the paragliding company Apco. Saw the pictures, but don't seem to have a copy. So a biplane ram air wing has been flown, but I don't know of a freefall deployable one. Peter Chapman Toronto, Canada

Another data point: My DZ in Ontario, Canada has six sigmas too. 1 1/2 years old. At least one also has a slightly bent pin.

Any photos of the Mr Bill landing???? ... that is of the round canopy getting full inflation (I think) just before water impact? My only photos are attached. From a 70 mm lens, point and shoot camera at the landing area. The first shows the separation of the two jumpers. The second shows the beginning of inflation. Unfortunately the water is not seen, but the bottom of the photo is pretty much the horizontal plane, judging from the trees. I'm guessing about 100' height with the canopy just starting to inflate. The jumper looks well head down too. Quite the rush. Thanks to Jason Bell and the other organizers & volunteers -- it was a great Bridge Day. Peter Chapman

That's why I say they shouldn't have to tell us all the details. But since their algorithm is a major part of the product -- in the sense that it affects the safety and main purpose of the damn thing -- it would be nice if they'd proudly say a little bit about what they've engineered into it. "So why is your product great?" "It just is. We're smart & experienced people, trust us."