pchapman

Oh my god, we're back to square one...sigh. No it doesn't climb quicker into the wind. Nothing changes turning downwind (excepting visual illusions and the special case of wind shear). No the stall doesn't change with or without wind.

The range of responses is kind of funny, even if they are all valid and have a point. Do an intentional? "Don't worry about it, if you keep yourself properly trained, when you actually have a mal, your actions will be automatic and be no problem anyway." Do an intentional with a spiralling main (pop a brake)? "Oh my god, no, that's dangerous!" So being stuck with a spiralling main when low and you don't expect it, seems to sound like no problem, while doing it higher when you are ready for it is dangerous. To reconcile those very opposite statements one may have to believe that: a) that simulating an emergency can be dangerous. (Yes, sometimes it can be.) and b) a real malfunction emergency is not really dangerous. (Well, hopefully not too dangerous if you are well trained. At least cutting away is very safe compared to the alternative of not cutting away!) and c) the improvement in safety you might get from the experience of an intentional is not worth the risk taken to get that experience. (That can be debated.) My personal opinion is still that you don't need to do an intentional but it is a good experience. Like anything new to you in skydiving, get some good advice first. I wouldn't object to it being done by people with well under 200 jumps. I wouldn't recommend the spiralling thing for ones first intentional, if one is still fairly junior. And anyone wanting to try it, should first do a jump or two where they play with popping a toggle after opening. The accelerating turn can be a little disorientating when one isn't actively steering a spiral. And it is good experience in how one's canopy behaves similar to if one does pop a toggle on opening. As for doing the spiralling intentional if one has an RSL hooked up, that I'm less sure about the answer. I'll leave that alone. I'd rather have the time to get stable after the chop.

Interesting about the C license. Rules vary - in Canada one only needs a Solo certificate, not even the A licence. (Manual deployment procedures appropriate to a belly mounted no-pilot-chute reserve need to be trained and signed off, however.) Still, whatever the rules, it isn't usually something done while someone is still a relative novice. It could be done more often but the big thing is that there usually isn't any really appropriate gear with which to do an intentional.

RW to FS: I don't recall the real story either, but I thought it was from the international, FAI level, to have names for disciplines that were rational to the outside world and public, and not just a historical artifact of skydiver speak. At least, the names have been adopted at the FAI level. Doesn't mean we can't informally use the skydiver speak.

Ok, I've got this partially figured out: The manual I have, which seems to be current (or at least the one floating around on the web for a company that is gone), doesn't have the V-fold, nor does the supplement for changes with no catapult. But some hand written notes I have show the V fold -- which I later crossed out. Thus I think it might be from an older version of the manual?? Generally the newest manual is clearly the best, but there are issues in the rigging world with the degree to which a new manual absolutely must replace an old manual, which I won't get into here. (The version without the S-fold keeps the bulk of the bridle under the bottom flap, or, without catapult, between the ears of the freebag to bulk that area up.)

1. I'd stick to the factory suggested bridle location unless you have a really good reason to change it ... and have the experience to back up the choice. (Besides, the FAA does require a US rigger to follow the manufacturers' instructions. Occasionally that is completely stupid, but usually it is a good idea to stay close to what they want.) 2. The right pull force? Often it's gonna be 20- 22 lbs, seriously. External pilot chute rigs tend to need to be snug to prevent them from showing fabric over time as the canopy compresses and the rig flexes. Sometimes tight rigs (of all types) will test still a little higher at first.... but you know that when you re-check the next day the tension will be down a bit, below the limit. The Reflex the instructions even say that after a few days a little snugging up is often necessary. That isn't always practical to do, so you get it snugged up pretty tight to begin with.

Certainly for a student the rule is probably all or nothing. I once saw first jump student land after he had a minor mal that cleared, and he had started to pull the SOS handle before that happened. I was right there as he landed with the handle dangling. One yellow cable was only 1/2 an inch past the loop, on the non-RSL side. There's a fine line between life and death at times...

I'll try another angle in trying to help explain why that momentum thing doesn't work: (Maybe there's a visual illusion down low that makes it seem that way?) Say someone were doing a high hop & pop or cross country, and the wind was howling at 50 knots or whatever up high where they were. If the jumper played around up there with their canopy you DON'T hear them say: "I'd make a 180 dive and it was really fast. Then I tried it again, and I couldn't figure out why the canopy was so sluggish. Then I realized: I was going downwind the first time, and upwind the second. When I spiralled, it was really weird, as the canopy kept on pickup up speed and losing it, every time it went in and out of facing that 60 knot wind, picking up and losing momentum!" Or what if a jumper made a hop and pop from some long range balloon that was doing 200 knots in the jetstream? Would it be hard to turn the canopy in some directions while it would go crazy in others?

I don't know for sure but my vague suspicions are: High wing plus bush plane origins; harder to hand pump fuel into the wings. (Not that ladders weren't needed anyway, if only to deice the wings & tail ...) The single Otter and Beaver had fuselage tanks too (didn't they?) so there's precedent from the company's earlier products. Not sure if a newly certified plane under FAR 23 or whatever would normally be allowed fuselage tanks any more -- there may be more emphasis on getting the fuel away from the cabin, no matter what disadvantages may occur too. (The Twin Otter was certified under the old CAR 3 preceding FAR 23.)

While Cypres 1's have been expiring for some time now, I've never seen photos from inside one, so I ripped one apart. Within the plastic Cypres 1 box with its metallized inner coating, the electronics are in thin soldered metal shell. This can be peeled off to show the electronics boards, two stacked ontop of each other. Under the metal shell were thin plastic shields presumably to prevent any shorting out. The shields were already removed before the photos were taken. Everything inside is potted in a gluey, rubbery gel that can be pulled off. I'm not into the details of chips, but the microcontroller is a Motorola MC68HC7. The pressure sensor from this 1997 Cypres is a US made one from Data Instruments, but shown as being part of their Next Sensors line. Next Sensors was created only in 1994, operated in Germany, and was later merged with Data Instruments. Given that Cypres' were on the market in about 1991, it suggests that Airtec did change components when something better came along (or perhaps something was no longer available). The "sensor side" pic shows the pressure sensor as the large black box at the right. Normally such sensors have two barbed connectors for tubing, but these were simply cut off to fit into the box. To the left of the sensor one sees 5 shiny bars which are just the cut-off heat sinks of what I guess are transistors. Airtec presumably slimmed them down to fit, not needing much ability to absorb power. To be kept in mind is that the Cypres 1 is basically a late 1980's design.

Brilliant! Here's my theory: While NIST may or may not have been sloppy about one or two analyses they made, evidence continues to mount showing how heavily damaged the buildings were, how the collapses related to particular structural damage, and how no record can be found of massive initiating explosions from demolitions. (Some think the buildings should have tipped over, because their knowledge of structural engineering comes from accidentally knocking over the tower they built out of LEGO as a kid.) It is all part of the conspiracy of course that the collapses had to APPEAR to be naturally caused, so that the distrustful public (so eager to find conspiracies) wouldn't suspect a controlled demolition. That's why the conspirators had to arrange their explosions or melting of steel to precisely correspond to normal structural collapses, initiated at the exact times that partial natural collapses started to occur. This also allowed them to avoid having to place tons of explosives or thermal burning material throughout the buildings while they still operated. I call this the "homeopathic thermite" theory. Infinity small amounts of diluted thermite, undetectable to forensics, were used to bring down the buildings, timed to mix precisely with structural failures just as they happened naturally from fire and impact damage.

Hmm, Mr Fradet seems to have the field covered. Booth's 2004 "Skyhook" patent application, 20040155153, is 10 pages long and basically shows a Skyhook with some slight variants. Fradet's 37 page long patent application in 2009 for his "Interlock" system, 20090127395, shows more than half a dozen significantly different variants of pins & grommets & loops to accomplish the task. So he not only keeps hidden (for now) what his preferred solution is, but also tries to keep a bunch of alternatives out of others' hands. He seems to know how to both design gear, and use the patent system. No other US patent applications related to MARDs showed up in a quick search.

nightBASE1: Yeah, that's a Canadian D licence.

There are a few of us old-canopy enthusiasts out there who jump Paradactyls from time to time, single or double keel, although the double keel ones are pretty rare. (Search for the threads in History & Trivia.) I see this is your first post. If you've got other tales & details from the old days, they'd be welcome! (This thread is an exception, but most of that stuff is over in History & Trivia.)

Yeah, I'm not against the rig. It has a lot of innovative features. But every design decision has its tradeoffs, good and bad points. It may be a 'proven rig' someplace else, but here, it still has to prove itself because little is known. So, yes, seeing more & bigger photos of the parts & details of the rig will be nice to let us over here learn more about it.

The web site suggests signing the petition if one wants an independent inquiry into finding out the truth. Who is against the truth? Yet the web site seems to be about a theory that the twin towers collapsed due to controlled demolition. It is interesting indeed that some think so, but the thousand signatures don't in themselves mean much to that cause if the petition is presented as simply asking for another inquiry to look for the truth.

In this thread we haven't yet been able to agree whether there is some wing loading below which it might get more dangerous to try swooping, at least for 180 degree or more rotation. While the one poster's choice of "most likely...get hurt" words is overdoing it, I still think at some really low wing loading the danger might go up. I've occasionally done steep diving 180s with F-111 7 cells at 0.65 WL (from 50 ft?) or get little swoops out of a similar canopy at 0.9 when doing a low tight 360 dive (from 150 ft?). That kind of stuff is usually seen as crazy shit at the DZ. While it could be that it's just not something people practice much, it does feel safer to do swoop approaches with a 1.25 wing loading canopy. (Which admittedly is ZP and 9 cell so has better inherent performance.) If I'm talking to some newbie at 1.0 loading and telling him he isn't ready to move up to a 1.25 wing loading canopy yet, I might encourage him to work on the downsizing checklists with his slower canopy, but I wouldn't tell him to keep going past 90 degrees until he can do 360 approaches. To some degree we're not just varying the wing loading in these arguments, but are often making assumptions about experience when we think about whether a particular canopy is dangerous for someone "learning to swoop". So we're not talking about the guy with 2000 jumps loading the same canopy brand at 1.6 versus the same guy at 1.1. Instead we might be thinking of the guy at 1.1 as having 150 jumps or something. This hidden factor also influences what we say on the issue. I'm still wondering if we should say to up and coming jumpers that they really shouldn't be trying to learn to do 180 degree plus accelerated turns to landing, even if they have good coaching, below a certain wing loading (perhaps modified by the canopy type's recovery arc), due to some inherent danger in doing so. Of course it is always easy to recommend more jumps in general before moving to that stage in swooping. Lets say the 150 jump guy gets another 100 jumps, then moves from 1.1 to 1.3 wing loading. (I'm not trying to be exact with wing loadings or follow the Germain chart, but just throw out some ballpark figures.) He then makes 50 more jumps getting really comfortable with his 1.3 loading canopy. He now wants to learn to do 180 degree swoops. One isn't going to recommend he go and do that on his old 1.1 loading canopy, is one, even if he has more experience on it?

"Oh, the humanity!" - Les Nessman, WKRP in Cinncinati, Turkeys Away episode

Thanks Pantanal. Clicky for the manual: http://www.basik.fr/en/images/Seven/seven_manual_02-09.pdf It doesn't have detailed pictures but enough to see the small flaps. Two mini flaps fold inward at the top of the freebag and there's a bungee to create a staging stow using the bridle. That's a very good way to stage the bag when there's little other container around the freebag.

Cueb: Part of the issue is figuring out what wing loading is "too low". Usually at 1.2 a canopy can be pretty lively and make little swoops without trying too hard. At 1.0, much less so. Although there will be other factors like the canopy type, it is hard to know what numbers to quote as a guideline.

This is an interesting topic on learning to swoop while still on low wing loadings, that isn't talked about much because usually novices aren't thinking about swooping much until on a faster canopy. I'm just guessing, but it seems that a lot of the basic downsizing exercises can be done just fine on a low wing loading canopy. 90s may be OK but going on to high performance 180s is perhaps best done only once a new jumper has moved up to a slightly higher wing loading so the recovery arc isn't so small.

It would be nice to see pics of the freebag out of the container. There's just one small one that I saw on the company's web site. There is some pocketing at top and bottom, with vestigial side flaps. All the buzz is about having only 2 flaps, but as the company has done, something is needed to pocket the freebag, keep the reserve risers from slipping out, etc.

This probably wouldn't be the right application for traditional vortex generators, although possibly for another kind. Traditional vortex generators are used slightly ahead of where attached flow would separate, adding energy that keeps the airflow attached to the surface for a longer distance and thus preventing a stalled region with little lift. I'm not sure that the attached flow on a wingsuit goes very far back from the leading edge, and a bunch of small vortex generators probably isn't going to make a difference given the angle of attack and quality of the wing. I'd guess one is dealing with one big separated flow vortex over each wing, as is typical for a low aspect ratio swept delta wing or similar at high angle of attack. Much lift then comes from the low pressure within the vortex. But I don't know much about airflow studies on wingsuits and haven't been watching the arguments in the last couple years. That doesn't rule out that one could have fewer, larger vanes or slots or something that set up a few larger lift producing vortexes. But it sounds fiddly structurally and could interfere with the main vortex too. So who knows.

So maybe you can squeeze it 2", plenty for the top pin, but then accumulated slack in the ripcord makes the bottom pin not quite clear the cone, and the MA-1 pilot chute may or may not squirm its way out... I'll think I'll pass.

That reminds me, I hear that Skydive America Palm Beach was an awesome DZ in the late 90s. Cheap loads, highly experienced load organizers, etc. Which the DZO could afford because he was defrauding his investors big time. It would have been cool to skydive there. All the benefits of crime, without the personal legal responsibility!