pchapman

I was curious about that so went and looked at their product literature and line trim charts and was quite surprised at how little has changed. Whatever they've achieved different between the two canopies is due to subtle changes. (And perhaps a small amount due to the material, but that should affect packing more than inflated shape or aerodynamics, especially when new.) The spans and chords and aspect ratios are identical for identical sizes. Maximum weights are increased for some models of Optimum, generally for the larger sizes to expand above 254 lb, but also in one smaller canopy, moving the boundary between 254 lb and 220 lb certification down by one size. (Opt 113 is good for 254 while the PDR 113 is only for 220.) Maximum suggested weights are generally the same. (However: Higher for those Optimums where the maximum certified weight went up. For very small reserves, occasionally the Optimum allows a slightly higher weight for more experienced jumpers, and expands the Not Recommended range for less experienced jumpers, making experience level slightly more important.) As for line trim charts: I looked mainly at the 143 model. (PDR revision E is current, OP revision A is current) Sliders are the same size for the 143, but a little bigger on smaller Optimums because their slider stays the same while the PDR's gets smaller. For big sizes, all are the same, keeping the same slider size as the 143. For the 143's, the A lines lengths are the same, as are additional B, C, and D distances. This suggests the attachment point geometry is likely the same too (same distances along the chord). For the 143's, the distance from the A's to the brake line attachments goes down 3.75" -- in effect adding more breaks. For the 143's, the lower steering line (above the eye) becomes shorter on the OP basically by the amount to make up the difference seen above (within a quarter inch)(and suggesting the cascades didn't change). For the 143's, the brake eye to toggle length goes up a whole 6". So some of that goes into making up for the shorter distance above the brake eye, and there's an extra couple inches of slack in there too. Maybe that helps the modern jumpers a little, those who expect the flare power lower in the flare stroke, but it really isn't much in that regard. The 99's are like the 143's: Zero change in trims, only some changes in brake line. Things can be different at different sizes though. Looking quickly at the 253's, there the basic trims are not the same, the PDR and OP have pretty much all numbers changed by up to 2". Just about everything was tweaked or revised. (One apparent large change is the LST shrinking by 11" or so, but brake cascades must be lengthened nearly as much, as the position of the tail relative to the A's is only slightly changed at about an inch shorter.) Brake to toggle length goes up even more, this time about 7", and that's with little change in the tail's position with brakes set, and probably not much in the general geometry, so a lot of slack is added. ===== For the 143's, with A,B,C,D trims the same on the same planform, that suggests the trim angle is the same too. I would have guessed the trim would be steeper for example, in order to give the Optimum more speed for an easier flare with more of a time window. But that's not the case! Indeed PD says the Optimums have a slightly shallower glide than PD-R's. (Technically one could change the trim angle if all the B,C,D trim points shifted along the chord, but that scenario seems unlikely, with actual trim values maintained exactly.) So where do the differences in the PD-R and Optimum opening characteristics come? For the 143's or 99's, so little has changed so that it comes down to only the deeper brake settings, or the fabric. Well, sail vs. ZP vs. F-111 does affect openings, so maybe the low bulk fabric behaves differently too when flapping around and subject to high pressures (even if it meets or exceeds F-111 style permeability in normal tests). Similarly, how about the landing characteristics? PD says the Optimum has a longer control range and even better flare. Does it actually stall slower or just have a longer stroke that changes the feel? Does the slightly lower angle of descent make it easier even though diving more for the ground would usually gives a canopy a better flare by giving energy for the flare? So with some things not changed at all, but some tweaking, plus the fabric change, it is hard to tell where the changes in opening and landing characteristics come from, at least from this analysis. [Edit:Or is there a change in the airfoil?] There's some PD / LeBlanc magic still in there...

He has good stuff but with the caveat (for those who haven't clicked through) that it is BASE oriented so that concerns may be different. One can pack for skydiving and not give a damn, in ways that would not be optimal for low altitude freefall BASE. Still, his work gets people thinking about the mechanisms of how pins pull.

An unfortunate side effect of that solid Vigil case. Friends and I had a similar problem in the US once, but they let us through in the end. Can't recall if they did an extra swab test.

So I googled and the found this for the playlist, hope it works https://www.youtube.com/playlist?list=PLMqCekDhfSja0GAZnz34dY2cyYZQNQFEb&spfreload=10

But life would be easier if you would stop poking into all of them!

To the thread in general: The summary in my head for this whole thread (and other previous ones with MEL laying down the law) is basically: A: "The FAA doesn't allow jumpers to do very much at all to rigs, and senior riggers also very little... far less than jumpers, riggers, and manufacturers commonly actually believe they can perform or actually perform in standard practice." B: "But the FAA are idiots who don't know anything and are out of touch with the way the sport works. " A: "That may be true, but they still make the rules." B: "But the FAA say so many things in different sources of theirs that are contradictory, allowing all sorts of things in some of them -- so I'll take those opportunities. And the manufacturer allows certain work too." A: "That may be true, but officially one has to take the most official documents like the CFRs/FARs and use the most restrictive requirements they list. And what the FAA says is law, not what the manufacturer says." Then in the end everyone makes their own choice about how much to ignore the FAA. You have a lot on the line and get queasy about liability? Maybe follow their rules more closely. You can walk away from it all and think a lawsuit is unlikely or bullshit? Ignore the FAA and follow industry standards. "Well, your honor, I followed the FAA's Rigger Manual AND what the manufacturer stated in its bulletin, AND standard industry practice. If the FAA now says differently, I don't know anything about that." You decide if that's likely to ever happen or be a good enough defense.

----- old thread revived ------- Vigil has an interesting manufacture date system for their Vigil 2+'s. Its so strict one might have thought it to be from Cypres. I just installed a customer's Vigil 2+ with a manufacture date on the card of week 19 year 2014, and saw another labelled week 17 -- which was late April 2014. So one can have a Vigil 2+ with the manufacture date within the "rejected" range from spring 2014 and that's OK. Presumably others have noticed this already but it can be a surprise. To recap, the Vigil 2+ was first starting to be announced April 2014. On May 21 they announced none would be available at the end of May as planned, due to a component not meeting Vigil's quality control standards. (No indication of whether the components themselves had a particular production issue, or generally had problems meeting their own standards, or Vigil had tighter standards or what.) This led them to "reject all manufactured units so far". A prudent move on their part despite its awkwardness. No actual service bulletin was needed as apparently no production units had shipped. August 7 they announced the first production Vigil 2+'s had finally shipped. Despite the Vigil having a longer approved life than any other AAD, it sucks a little for the customer to have one dated back in the "rejected" period, over 3 months before any unit shipped.The clock was already ticking, and the factory wasn't going to date it when it actually finally fixed / reworked / rebuilt and was about to leave the factory. (I am checking with Vigil just to confirm.)

Although I'm going a little off topic, cats have also been taken up in a T-33 military jet trainer to test their orientation and righting capability in low or zero-g. The attached photo is from a 1957 aerospace medicine journal. The results weren't actually too exciting and would take some explanation. Basically, adult cats with a developed righting reflex (unlike the kittens they also took up!) would tend to try to flip over if released upside down despite being in zero G, whether hooded or eyes open. Cats aren't generally big on being upside down. But after repeated zero G parabolas, they would get used to it and just float. Or they would right themselves once G's started to applied even a tiny bit at the bottom of the parabolic arc. Thankfully we had brave men like this in the United States Air Force (plus ex-Nazi era scientists) to make sure the godless Commies did not take the lead in feline righting reflex science. Reference: The Labyrinthine Posture Reflex (Righting Reflex) in the Cat during Weightlessness BY SIEGFRIED J . GERATHEWOHL PHD, AND MAJOR HERBERT T. STALLINGS, USAF, Journal of Aviation Medicine, Aug 1957

That was lowish indeed. One first sees the canopy snivelling overhead at :42, and he's on the ground at 1:55, 1 min 13 sec later, with an apparently medium sized canopy flying mostly straight in brakes. Although the untwisting largely stopped when the lines untwisted to the point where "they hit the risers", he was able to untwist a little more to clear the toggles. That was nice as it allowed him to rear riser turn presumably somewhat into wind for a softer landing (facing out to sea at Dillingham). He also used the brake lines above the still set toggles to get a little flare, although the initial airspeed wouldn't have made for a good flare. I figure he would have had time to pop the toggles, letting the canopy dive for airspeed and still flare, but he probably didn't want to muck with things much at that point. (I once landed hanging sideways with twists on a big old canopy due to a CRW wrap. The other guy's jettisoned and deflated main was still trailing from the risers - I was through a few lines of it. At least once I got my head back through the twists I could find the toggles above the twists, and flare somewhat normally.)

The lesson is that if you ask a million questions here, people will get bored or annoyed by you. Not every student's questions get answered completely; sometimes a student has to go back to the dropzone and deal with their own instructors. ...Even if your questions are technically valid, and you were correct in observing that toggle colours are not always the typical ones some of us expected.

Fair enough, not a problem at some DZ's. I was thinking of a situation where a DZ mentions toggle colours as part of the training.

Yeah, after all that work they did to get the shots, too bad about the toggles on main and reserve! (Don't know about everyone else's gear, but I'm more used to Yellow for main, Red for reserve, rather than the reverse.)

Congrats on staying with the sport so long! Wish I could be there for the old canopy fun but it is a bit far to come down just for the weekend! Hope someone gets some good photos of old gear in addition to the inevitable video. Peter Chapman Sensor/Double Keel 'Dactyl --- Single Keel Dactyl --- 'knights' PC --- 'pizza puke' PC --- Russian paratrooper D-6 rig --- PZ-81 Rogallo --- UT-15 rig --- a few round reserves --- Stratocloud --- Strato-Star* --- ParaSled* (*=not yet jumped) ... yeah some people have plenty more...

Long ago I think there was a thread on the subject if someone wants to search for the link. One individual bound to get mentioned is TK Hayes, a well known jumper & DZ manager. TK stands for Tent Killer. I've also known a "Crash", a "Ditch", and a "Thumper". But often one doesn't actually know the back stories....

Hmm, I checked the 1985, 1998, 2001 and 2003 Racer manuals (the latter being current) and they do indeed mention Type 5 Nylon Cord Sheathing. (1000 lbs minus 14 strands for the sheathing) I have been using the sheathing of Type 4 nylon line (750 lbs minus 11 strands). I must have been given some information years ago leading me to believe Jump Shack used that at the time, and then buy it specifically for the Racer.... but I can't find any reference to it at the moment. Clearly the manuals don't agree with what I chose, even if the end result of using heavy nylon sheathing is very similar.

Ok I'll give it a shot although there are others who know more about the TSO process from actual work in the industry and not just reading about TSOs: There have been some discussions on dz.com about the different TSOs and trying to understand them, but I don't have any URL's handy. Collecting the TSO's and referenced stuff like AS8015 from the web takes some time. (Can send some info if you want) Things also change significantly between each of C23b, c, d, & f. C23c / AS8015A just mentions a canopy being "fully open". The way I've heard it, it was easy just to use video to see when the slider hit the links. Easy for a company to measure, but not very useful to a jumper as the canopy could still be mushing downwards and not actually flying yet. C23d / AS8015B tightens up the definition to say "Functionally open shall mean a parachute sufficiently deployed to provide a rate of descent equal to or less than the limit specified in 4.3.7". This may take some more instrumentation than in the old days. Matching harness and canopy limitations is a bit messy because TSO versions vary so much. AC-105-2D (current I think) says: "the strength of the harness must always be equal to or greater than the maximum force generated by the canopy during certification tests" … BUT there's more about when you mix and match different TSO versions. E.g., when mixing a C23d reserve and a C23b Low Speed harness, "the system is limited to the placarded performance limitations of the canopy or the structural limitation of the harness (3,000 pounds), whichever is lower." Which is sort of impossible to do in practice. If the reserve says it generates an average 4100 lb at 150kts and 254 lb, there's no way of knowing what limits to use so that you never go above 3000lb. But technically that applies to the C23b Low Speed Mirage (even if it is considered as strong as any other rig where the companies bothered to spend all the money to get a newer TSO). (People say AC105 is only advisory and not law, but at the same time it is the considered opinion of the FAA so it may not look good to ignore it either.) The manufacturers vary in the detail of the numbers they put on C23d canopies. One company (Icarus) has the same force listed for all their canopies. Another (Jump Shack) divides it into two forces, one for the bigger reserves and one for the smaller. Presumably all of the canopies within the group do not exceed the force they list. Then another company (Parachutes de France) list a different force for each canopy. One thread with discussions on canopy forces: http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4676423;0search_string=maximum%20peak%20force;#4676423 A lot of rigs and canopies are certified for 254 lbs, but some smaller reserves for less, some rigs and reserve for more because 254 lbs got to be too low for some people nowadays. 150 kts has been a common certification standard although higher and lower numbers have been possible depending on the TSO. Anyway, you'll probably just have to do some more reading of the regs …

XKCD covered that nicely: "20th century headlines rewritten to get more clicks" http://xkcd.com/1283/

I checked a Swift II manual, that says it is a 1985 update of the 1981 Swift, with better riser covers and redesigned main container. It clearly states that is was designed and tested only for the Swift and Cirrus square reserves. (I have no idea if some riggers might have put in a round instead, considering it compatible anyway.) It sounds from the manual like the main container on the Swift II could come in different sizes to take a range of ParaFlite canopies, Cruislite to DC-5. It would be a pretty progressive DZ to go to a square reserve for students in '85??? (Or maybe advanced students?) Not quite sure of the timing.

Decent words. But I'll say in defence of the perhaps over-enthusiastic newbie, that he has tried: There was no instructor to help him at the busy DZ and he presumably thought more about the issue after getting home. And pulling the handle correctly is a big part of doing what you need to do to save your own life. And he is aware that there is uncertainty about his perception and what actually happened. But yeah we may not be able to solve all his questions here, so wmscott does need to just go and do another jump and work with the instructors he gets...

You're definitely one of those "I want to know everything!" detail oriented students. Sometimes a pain in the ass, who has to be asked to quiet down, and needing correction for wrong ideas picked up .... but better in the long run than those who can't be bothered to learn and study or care about their gear. Anyway, on the Sigmas if it was the reserve there would be one loop each, the toggles would be red. If you could reach up into the toggles, both your and your instructor's hands would be in the same loop. No drogue or pilot chute would be trailing behind the canopy. If it was a main, the toggle would be yellow and have a loop for your hand lower down, and a loop for the instructor's higher up. The drogue would be trailing behind the canopy but you might not be able to get your head up high enough to see it. (For the main, there might be tiny secondary toggles too, black, that the instructor would use in addition to the yellow ones for landing, with some but not all canopy types.) It would be pretty unusual for a decent hard pull on the drogue release handle to not release the drogue. Hard pulls -- one's which don't have the desired effect of pulling out the pin -- are very rare on the system. Still hard to tell what the situation was on your jump. Edit: OzzieDave could of course be right too -- based on your postings, you might be just a little overamped in the air too.

You are correct. A significant difference from the later Firelite also of 172 ft. sq. I did not know that and had to check the manual. Used the regular 400 lb Dacron lines. When one is used to A,B,C,D, having 25% fewer lines (excluding brake lines) might make one a little more nervous about the reserve!

$300?? but probably only to someone who has jumped at least 25years and understands the old stuff Heck, having gotten licensed in '90 I still know the differences between a Vector I and II, think I know a Firefly is to Firelite as Django is to Glide Path, but don't know whether a Pegasus was fast opening or slow opening, although I know it was really popular back then. It would be a fun old rig to play with and show off, especially if in garish early 80s colours --- or was it all bounce-and-blend by then? I just don't know. Sorry, but the rig is pretty much only of interest for old gear enthusiasts with spare cash -- even if technically it may be is fully functional in saving one's life. Edit: I'm saying this as someone who has jumped even older gear so I'm not against old stuff per se.

Cool. I don't know about the weight and how it compares to more conventional steel plate and such. In tank armor they have been playing with and using ceramics for decades, sometimes using armor with multiple layers of material of different densities to disrupt the path of a projectile. Some interesting ideas though, to use loose rather than fixed armor elements.

FWIW, the standard in Canada with the CSPA has been to have one jump of some sort before entering the PFF program (our AFF), whether S/L, IAD, or tandem. Nevertheless, DZ's can get waivers if they want to offer PFF from jump 1. Nowadays specific tunnel training is also accepted as a prerequisite for PFF.

It can be tough to fit in if one isn't one of the regulars, and every DZ has different skill sets around. In one place, most RW may be casual and it is easy to fit in. But at another place, everyone has a bunch of tunnel and are really serious about their RW. One has to look for what kind of jumps at the DZ one is qualified for, and who is doing them. There's often a minimum level of competence needed for a certain type of jump with enough safety that others will consider inviting you along. One also wants to appear competent in general. If you know your gear, don't get confused over exit order, can fly the approved patterns, land without falling over, etc., that can all alleviate concerns about 'jumping with her!'. The freefly may be out (at least beyond 2 way sitsflys, depending on your experience). The hard core RW may be out. Maybe you're at the stage where pickup 2 or 4 way belly jumps are what's mainly needed. So who at the DZ is doing them? Adding to the difficulty is not being a regular. The regulars at your level will be regulars because they are jumping all the time, so by next season you might not be keeping up with what they want to do and you'll lose them as jump buddies. So it is almost like every year you'd have to keep an eye on who the new newbies are, especially the ones who aren't always out at the DZ. Solo jumps can be used to play with some skills but lack of feedback is a problem in the long run. Some reflection on why others aren't enthusiastic with jumping with you is on order. Socializing isn't supposed to be such work but sometimes one just doesn't naturally fit in as well, so one has to pick and choose more carefully where to put one's effort. I'm describing awkward reality more than offering solutions but it could still help.