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Tony-tonysuits

URGENT....Apache owners, discontinue use of new handles

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I don't base, but would'nt it be a really bad idea to test jump a new suit in the base enviroment ? The base jumpers I've met do lots of practice jumps from planes with new suits.



You can't practice BASE exits or anything like them in skydiving (unless you're lucky enough to have a balloon) so you will always be test jumping a new suit in the BASE environment anyway. And compared to exiting, flying straight and level is a piece of piss. Especially if you have anything like the requisite experience on other huge suits before you get an Apache.
Do you want to have an ideagasm?

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Apache suit owners,

Today in testing, we've found that the pull strength with the auxiliary handles we've shipped out recently on our Apache model wingsuit can be higher than the TSO standard.



That's a bit of an understatement of the situation. The tests in the video below shows cutaway pull force exceeds 30lbs and the metal reserve cable cannot be pulled even with more than 50lbs force applied in any direction. https://www.youtube.com/watch?v=1zJFQdOs1Ic

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We recommend you NOT use them.


Recommend? You should insist that none of these suits are used for skydiving until the problem is properly analysed, fixed and tested. This is a fatality waiting to happen.

The subject of your post says 'URGENT' why is this information not on your facebook page or website?

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One look at that handle system and the first thing anyone with any mechanical aptitude is going to say is, "uh...that might massively increase pull forces".

I can understand if some subtle thing were missed in testing, but it is so ludicrously, freakingly obvious that that system might fail and needs careful testing.

At least it wasn't exactly a mass market product aimed at newbies.

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I can understand if some subtle thing were missed in testing, but it is so ludicrously, freakingly obvious that that system might fail and needs careful testing.



Careful now, your post might get deleted!
Do you want to have an ideagasm?

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The appache add on handles in the video consisted of a french link that was placed around the reserve cable between the handle and housing that was connected to loop located outside the suit. (cutaway was the same)
It showed the apache reserve side add on handle being pulled on while in a flying configuration in several different directions (according to the directions and others) with about 50 pounds of force applied and no reserve activation. it showed that without the suit in place but using the apache attachment directly that it took about forty pounds of force to activate the reserve and only because the real reserve handle was able to come out its pocket and the force was then transferred into a normal pull configuration.
It also showed that it took about forty pounds of force to pull the cutaway cables using the apache add on handles.

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french link that was placed around the reserve cable between the handle and housing that was connected to loop located outside the suit. (cutaway was the same)



I wanted to buy an Apache for a while but I never got my hands on one for very long and I didn't get to see the cutaway system. That's a horrible design and I'm surprised that it only took 50 pounds to activate.

Is that the setup the manufacturer recommends? Do Apache pilots normally skydive with their reserve/cutaway handles out of the pockets?
This isn't flying, its falling with style.

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That's a horrible design and I'm surprised that it only took 50 pounds to activate.



The reserve did not activate with the suit closed, even with in excess of 50lbs applied is various directions, and even with the reserve out of the pocket.

The activation at 50lbs occured with the suit open, so the handle could move away from the jumper.

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And the test video is not available "due to a copywrite claim by Douglas Spotted Eagle." Uh???

Anyone who saw it want to describe it for the rest of us?



The video was made for industry/manufacturer-eyes only, and out of respect for the manufacturer and their crew, it was not public. Someone copied the footage and put it on YouTube without my authorization.
I asked YouTube to remove it because I still feel the manufacturer should be the one responding to the public.
To be clear for those that didn't see it; while using the thumbloops, no amount of pull force resulted in a reserve activation on multiple tests. This result may vary somewhat from rig to rig.

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Do you seriously think we care about the "respect for the manufacturer?" Why not call out a shitty solution, that's sold to the public in public, and spur some innovation? I'm uncurrent, relatively inexperienced and not even a gear manufacturer/salesperson but I could build a better solution to that problem in about 30 minutes (I bet most heads up jumpers probably already have) Hint: cantilever = bad

It's supposedly a BASE-specific suit, so who cares anyways. There's no way that anyone would market and sell a BASE-specific suit with a shoddy workaround so the rest of us can use it, right?

That said, what a person shares is up to them. Even after the video, I'd probably still want to buy an Apache (not to skydive with) if the lead time wasn't so long.
This isn't flying, its falling with style.

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Look everyone, an armchair quarterback.

Whom ever said the problem is the 90 degree direction of pull is the problem is incorrect. Think of how an RSL works. The problem is the distance of available pull and the force available.

Study what the testing force requirements on a TSO'd ripcord re and you'll see why.
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You're not as good as you think you are. Seriously.

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Yep, that's me, and from my armchair I'd say that if it was TSO'd 50 pounds should be more than enough, regardless of direction, and if I could read I'd say that AS8015B does also.

I thought I remembered something about moments, transmitting force, and axial loading in a book too, but I'm a moron it seems. This is evidenced by the fact that when carrying steel bars, wooden beams or other relatively rigid items through doorways I prefer to hold them sidewise and push reeeeaaallly hard, sometimes I pull too.

Anyone want to join me in disavowing the principles of physics? I have another armchair somewhere.
This isn't flying, its falling with style.

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why an RSL can pull the pin at 90 degrees to the cable at less then the weight of a fully packed rig?



That sure depends on the rig!
No problem on an older Vector II I played with, but not for a tight 24-25 lb heavy Wings I just tried. Even in an idealized zero cable drag situation, with the weight being divided along both directions along the cable which is bent out in a loop, that's only some 12 lbs pulling on the ripcord pin, well under the pull force for a tight newly packed rig.

As for the video, I was snuck a link to one of those file upload sites, depositfiles.com/files/l3harefp0

Seems to work. At least it isn't out on youtube for the general public; but sure is handy for debugging the issue without having to simulate the situation at home.

Who knows exactly where the extra drag comes from. If it might take 20 lbs to pop the pin for a tight rig, that's 40 lbs split between both ends of the cable. If 50 lbs on the scale didn't pull it, there's over 10 lbs of hidden extra drag in there somewhere. Possible sources might be:
(a) pulling against the ripcord handle - true for some of the pull directions used in the video but not all of them,
(b) drag of the ripcord cable around the end ferrule of the ripcord housing (less slick than an RSL guide ring), and
(c) friction of the cable going through the slot in the suit - even though the slot does have some length to allow the ripcord cable to bulge out.

One would have to look at the drag of ripcord cables going around corners of fabric, ripcord housings, and as a comparison (to fit with what diablopilot was pointing out), RSL rings.


Edit:

I tried an experiment just now with an old ripcord cable, housing, and two scales. To get a 20 lb pull on a pin, by pulling the cable at 90 degrees at the far end of the housing, it took 25 or often 30 lbs of pull -- the number varied as the cable alternately caught and slipped a bit as it ground into the edge of the housing ferrule.

This was for a ripcord housing secured right up to the ferrule, as some rigs do it. Others allow the last inch or so of the ripcord housing to bend freely, creating a much larger radius, which I confirmed drastically reduces the extra drag "around the corner"

I'm sure it would go smoother if bending the cable around an RSL ring instead.

The rig in the video, a Voodoo, has the ripcord housing secured right at the end with an Oetiker clamp. Not so good for off axis pulls!

Yet there is still some flex, in that the whole lift web can bend and twist to allow the housing to curve, so the ripcord cable isn't right at 90 degrees to the housing any more. That's seen near the end of the video where they pop the reserve at 40 lbs when not pulling through the suit. There might be less twist in the air with the harness loaded, or when pulling through the suit.

So I think the 'around the corner of the housing pull' is a big factor in the problem, especially on certain rigs.

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