Incident Report - Aerodyne Brand "Slinks"

[tdog 0]

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For comparisons sake only (I think they are a good product) PD Slinks have a pretty common mode of failure when assembled by novices who don't RTM.

French links are often not installed correctly by those who don't RTM.

True... However, those two systems are easy to inspect.

If you can make either system safer, please post the solution here. Or make it and sell it and I will buy it.

I posted my solution in my first post to something that I believe has a "user error" possibility that is unnecessary. The solution... A solid tab (like PD brand) or ring so you can't misroute, even with or without the manual. Creativity could make it even better.

I have attached two photos. I made my own ring type soft link with cypres cord and a keychain ring - the best materials I have since I don't have a real one here.

From these photos, which one is correct, which one is wrong?

My point is to say - the system is very hard to inspect as being wrong, even when you know what you are looking for, and I think there is a better way.

Out of context, in an enlarged photo, it is easy to see which one is correct. Now put them on a rig with 100 other things to inspect, in a tight fit, in the fold of a riser.... Even the best rigger might overlook it once.

My opinion only.

[dragon2 0]

The first is correct.

I really don't understand the big deal here, everyone at this side of the pond knows the PdF version of the slinks which look the same as Aerodyne's, also there are more manufacturers with the same design (metal ring). Seen 'em once, seen 'em all Yeah you can connect them wrong but PD softlinks have one step extra so that's one more step to get wrong. RTM, no big deal no?!

ciel bleu,
Saskia

[DougH 270]

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Do you think maybe somebody learned something about installing aerodyne soft links because he posted his concern? Isn't that a good enough reason to post it publicly instead of just telling the manufacturer?

Come on Dave. They come in a baggie with instructions, and when you use them again they can be found on the aerodyne website.

I have put together Aerodyne slinks a handful of times... shhh don't tell the FAA.

If you need a post on dropzone.com to correctly assemble a set of slinks then you have no business any where near the assembly of a set.

"The restraining order says you're only allowed to touch me in freefall"
=P

[pilotdave 0]

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Come on Dave. They come in a baggie with instructions

They gave me four "loosies" with no instructions at the PIA symposium a few years ago. I still have em somewhere...

Dave

[pattersd 0]

I think you need to understand that PD has a patent (or maybe its just pending) on the idea of soft links with no metal. I believe the idea of a soft link with a metal ring predated the PD soft link and is not patented. Demanding that Precision infringe on PD's patent to idiot proof the design is not going to get very far. from PD's patent application "
With either method, the present invention provides a soft connector link, which eliminates the need of any metal hardware thus reducing the weight and the cost of the link. Furthermore, the connector link is easier to install as opposed to previous connector links, and does not require any sewing or tools for installation."
the patent number is 6,270,128 and the application date is aug 2001, so unless the patent office denies the application PD has rights for quite a few more years.

[tdog 0]

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RTM, no big deal no?!

I think I am done with this thread, as I have said my thing. This will be my last post unless someone has something other than, "read the manual" as that point has clearly been expressed.

Here is my closing observations from productive comments from riggers in the field:

In the field, they have observed on main and reserves, the ring style soft links installed improperly or caught themselves doing it. You will notice that they were both experienced riggers.

People have commented that improving product designs to eliminate possibility of error, with or without a manual, is a good thing.

So conclusion:

While it is true that reading the manual solves all the world's problems, my feeling is that product designs can always be made better - and the one of the ways to make them better - is to find user errors in the field and design around them, striving for simplicity. (We are not talking about adding computers to monitor soft links or complicated back up devices to make sure your AAD is on or something, so don't flame me on this one... We are talking about the progress that took us from Capewell to 3 ring, rip cord to throw out, leg to bottom of container, and all the other major and minor changes in the last 30 years).

No one yet has proven to me that this user error in the field would be possible with a solid tab instead of a ring... So my question is - if we can eliminate one more reserve ride - one more possibly incorrectly hooked up reserve - by simply changing one thing.... Why not change it? If the manufacture chooses to, more power to them. If not, I still will defend them as having a safe product when the manufactures instructions are followed.

[tdog 0]

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I think you need to understand that PD has a patent (or maybe its just pending) on the idea of soft links with no metal. I believe the idea of a soft link with a metal ring predated the PD soft link and is not patented.

My first post said "solid tab" not "non-metal." A Cypres washer is a good example of a metal solid tab with holes in it to pass line proven not to cut lines taking sharp bends around it. Just move the hole. Problem solved.

[riggerpaul 1]

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I think you need to understand that PD has a patent (or maybe its just pending) on the idea of soft links with no metal. I believe the idea of a soft link with a metal ring predated the PD soft link and is not patented.

My first post said "solid tab" not "non-metal." A Cypres washer is a good example of a metal solid tab with holes in it to pass line proven not to cut lines taking sharp bends around it. Just move the hole. Problem solved.

First off, I have seen a link that was made with an actual CYPRES disk. Moving the hole is not absolutely necessary, and the extra holes do not hinder the functionality.

Secondly, sorry, but I also have a comment about RTFM.

For a (USA) rigger, RTFM is not just a suggestion. It is required by law.

FAR 65.129(f) states that we may not "Exercise the privileges of his certificate and type rating unless he understands the current manufacturer's instructions". Failure to take the time required to obtain and digest the appropriate documentation violates that requirement.

So while ignorance may be an excuse for a non-certified individual, it is not an acceptable excuse for a certified rigger.

tdog, please don't misconstrued this post to be a criticism of your valuable comments regarding the improper use of the Aerodyne soft link. I totally agree with what you have said about the failure mode of the existing design. I agree that the design would be greatly improved by replacing the ring with a solid disk that has small hole. Such a change would, as you point out, eliminate the possiblity of this particular error. By the way, the ring is really just a disk with a *big* hole in it. All we are really saying is that the hole needs to be smaller to eliminate the possiblity of incorrect assembly.

Anyway, thanks for bringing this problem to the limelight.

[fcajump 153]

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The first is correct.

I really don't understand the big deal here, everyone at this side of the pond knows the PdF version of the slinks which look the same as Aerodyne's, also there are more manufacturers with the same design (metal ring). Seen 'em once, seen 'em all

Yes... but seeing them for the first time is the rub...

I got my first set from Precision (don't even know if George went to production with them)... and had the SAME problem when I first tried to connect them. Figured out that there MUST be a problem and redid them until I got it right. I also decided to tack them before that was common practice.

While I like them, they are NOT your older brother's F-links. They take different attention, maint, inspection and replacement. Too many people think that they cure all hard links problems without causing new ones. During this last year, on this site, we have seen that they can be packed: in an incorrect state, incomplete state and too worn to be safely used.

For those that don't already have them, here are Aerodyne and PDs posted instruction locations:

http://www.flyaerodyne.com/download/SoftLinkManual.pdf

http://www.performancedesigns.com/docs/SlinkInstructions_1.pdf

Get them, read them and ASK questions... too easy to get them wrong if you assume.

JW

PS - PD also has a page about SLink with "hats"
http://www.performancedesigns.com/docs/SlinkInstructions_RCI.pdf

Always remember that some clouds are harder than others...

[LloydDobbler 2]

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Do you think maybe somebody learned something about installing aerodyne soft links because he posted his concern? Isn't that a good enough reason to post it publicly instead of just telling the manufacturer?

I agree. That's the main thing. I personally never would've known to double-check for this had I not read this thread. Now I know.

It's not going to keep me from using Aerodyne soft links...but it will make me more vigilant if I know the links are Aerodyne.

So in a cost/benefit analysis, I (admitted newbie) think the benefits far outweigh the costs of calling out a potential point of failure and making people aware of it.

Signatures are the new black.