Curv, CPX not working very properly

[eric.fradet 17]

A French rigger recently, reported to me an issue he found during a regular packing cycle on a Curv 2. After pulling the reserve handle and the reserve container opened up, the rigger is used to take the reserve canopy out by pulling the reserve bag by its bridle in order to let the canopy takes the air out for the next 3 days

in this case, the rigger was not able to get the risers cover open up, they stay locked even by statically pulling with all his strength (about 60 pounds force), even he made several tests with different traction angles without success on this Curv 2 while it does not take so many tension to release magnetic risers cover on others rigs

We were able to duplicate the issue on some others Curv 2, Curv 1 , CPX rigs.

It did not take us long to find out, Curv and CPX are poorly designed regarding reserve extraction with not enough flexibility at the base of the reserve pin cover flap, it definetly forces to open the riser cover up, specially on rigs with small yokes.

Consequently there are 3 risks on some of these R.I and Sunpath equipment :

- both riser cover flaps stay locked up with the slider keeping skydiver head pinned down

- If the riser cover delay opening until the slider begins down the lines and then they suddenly release, the slider will come down the lines like crazy causing an incredibly hard opening.

- If the hang up is only on one side with one riser free, it will cause a spin of the main.

Then you can get a different result if you reproduce a whiplash but wondering if it is realistic

Curv 1.0 DOM sep 2013 # 15649.xspf

[eric.fradet 17]

On 2/14/2022 at 2:18 PM, eric.fradet said:

A French rigger recently, reported to me an issue he found during a regular packing cycle on a Curv 2. After pulling the reserve handle and the reserve container opened up, the rigger is used to take the reserve canopy out by pulling the reserve bag by its bridle in order to let the canopy takes the air out for the next 3 days

in this case, the rigger was not able to get the risers cover open up, they stay locked even by statically pulling with all his strength (about 60 pounds force), even he made several tests with different traction angles without success on this Curv 2 while it does not take so many tension to release magnetic risers cover on others rigs

We were able to duplicate the issue on some others Curv 2, Curv 1 , CPX rigs.

It did not take us long to find out, Curv and CPX are poorly designed regarding reserve extraction with not enough flexibility at the base of the reserve pin cover flap, it definetly forces to open the riser cover up, specially on rigs with small yokes.

Consequently there are 3 risks on some of these R.I and Sunpath equipment :

- both riser cover flaps stay locked up with the slider keeping skydiver head pinned down

- If the riser cover delay opening until the slider begins down the lines and then they suddenly release, the slider will come down the lines like crazy causing an incredibly hard opening.

- If the hang up is only on one side with one riser free, it will cause a spin of the main.

Then you can get a different result if you reproduce a whiplash but wondering if it is realistic

essai K avec octavie 2 .mov

Curv 1.0 DOM sep 2013 # 15649.xspf 585 B · 18 downloads

definetly not working properly...below 60 pounds force

[gowlerk 2,098]

So, what does this show and what is worse? Riser covers that don't release till later in the reserve deployment sequence or riser covers that don't stay closed during high speed skydives? And why do so many irrelevant static tabletop faux problems seem to be popping up here, almost exclusively from France? This is a non issue.

Edited February 17, 2022 by gowlerk

[JerryBaumchen 1,263]

1 hour ago, gowlerk said:

So, what does this show and what is worse? Riser covers that don't release till later in the reserve deployment sequence or riser covers that don't stay closed during high speed skydives? And why do so many irrelevant static tabletop faux problems seem to be popping up here, almost exclusively from France? This is a non issue.

Hi Ken,

IMO it is for sure a 'non issue' for the FAA.  They will only concern themselves with that which is certificated; riser covers are not certificated.

Jerry Baumchen

Edited February 17, 2022 by JerryBaumchen

[sundevil777 98]

1 hour ago, gowlerk said:

So, what does this show and what is worse? Riser covers that don't release till later in the reserve deployment sequence or riser covers that don't stay closed during high speed skydives? And why do so many irrelevant static tabletop faux problems seem to be popping up here, almost exclusively from France? This is a non issue.

Rather than making a conclusion from simulating on a table, this could be more realistically simulated without too much trouble.

[eric.fradet 17]

2 hours ago, gowlerk said:

So, what does this show and what is worse? Riser covers that don't release till later in the reserve deployment sequence or riser covers that don't stay closed during high speed skydives? And why do so many irrelevant static tabletop faux problems seem to be popping up here, almost exclusively from France? This is a non issue.

not sure it is a non-issue to jump a rig, with riser cover not able to open when you pull the reserve only, whatever it is legal or not, Sandy Reid is dishonest and not qualified enough to certify a rig without even tested it, It is exclusively from France since there is no other country where people like me are paid only to find out the design flaws

[gowlerk 2,098]

1 minute ago, eric.fradet said:

not sure it is a non-issue to jump a rig, with riser cover not able to open when you pull the reserve only, whatever it is legal or not, Sandy Reid is dishonest and not qualified enough to certify a rig without even tested it, It is exclusively from France since there is no other country where people like me are paid only to find out the design flaws

I see. I know Sandy a little. I would say that this post says more about you than it does about him. But I guess you are on a mission of some sort.

 

[Mountainsky1 0]

Must be winter time in France... Nothing better to do... Eric before you start slinging shit about a particular person I suggest you put your French elitism temper in check. There have been many a French manufactured rigs that where not quite up to speed. 

[gowlerk 2,098]

5 minutes ago, Mountainsky1 said:

Must be winter time in France... Nothing better to do... Eric before you start slinging shit about a particular person I suggest you put your French elitism temper in check. There have been many a French manufactured rigs that where not quite up to speed. 

Isn't he the angry guy who keeps complaining that he invented a MARD and it was stolen from him?

[Mountainsky1 0]

Now that you mention it. If anyone has a right to be an angry old man it's me...LOL

 

[Quagmirian 40]

Something here that no one seems to be mentioning so I will. On the floor, the jumper will rotate upwards pulled by the risers with their feet as a fulcrum and their entire weight resisting the rotation. In freefall, the risers will rotate the jumper around their centre of mass with very little resistance, increasing the bend in the risers and increasing the peeling force on the riser covers. Also, so what if you land with closed riser covers?

[sfzombie13 319]

another thing that seems to be missing here is the similarity between this thread and the one about the tandem rigs.  started very similarly, with an accusation from a french jumper, then got argued about and denied for a while until it turned out they were right and got a service bulletin or whatever happened.  maybe we should not be so quick to just dismiss things like this and wait and see if it happens again before trashing the folks finding this shit.  maybe we need to take one or two of those national director spots that someone is asking to go away and pay someone to find flaws in equipment like the french are doing.  it seems to be working for them so far.

Edited February 18, 2022 by sfzombie13
clarification

[Deimian 43]

1 hour ago, Quagmirian said:

Also, so what if you land with closed riser covers?

I don't think that is a big problem (it might be a small problem though, as toggles are not where you expect them, and if you are low, every second to grab your toggles help). But uneven release of riser covers during opening can very easily put you in twists. If you have line twists under your reserve, and the reserve starts spinning, then you have a big problem. There have been a few fatalities like that.

I think Eric is coming out as an angry-whiny man with some agenda to cover, as some others pointed out. But this does not invalidate the argument, it simply makes the person with the argument annoying. I think it is a good thing that flaws, big and small, are pointed out. Just knowing the issues the gear has, can the gear be improved. And manufacturers do not always see the issues in their product straight away. A friend of mine had a very serious incident some years ago due to a design issue on his gear. I would have preferred that someone coming out as a whiny annoying old man with limited online social skills found out before my friend, so my friend wouldn't have shat his pants or worse.

[skydiverek 61]

 

Similar tuck tab problem addressed below:

www.flyaerodyne.com/wp-content/uploads/2017/05/SB140111.pdf

 

Edited February 18, 2022 by skydiverek

[pchapman 275]

Whether this problem "is a real one or not", it is in that category we have seen over the years where "pulling slowly while on the ground" seems to cause a problem, not overcoming friction, while a faster yank while in the air doesn't cause a problem... usually, maybe.  That's the tricky bit to figure out...

 

[wmw999 2,313]

53 minutes ago, Deimian said:

I think Eric is coming out as an angry-whiny man with some agenda to cover, as some others pointed out. But this does not invalidate the argument, it simply makes the person with the argument annoying. I think it is a good thing that flaws, big and small, are pointed out. Just knowing the issues the gear has, can the gear be improved. And manufacturers do not always see the issues in their product straight away. A friend of mine had a very serious incident some years ago due to a design issue on his gear. I would have preferred that someone coming out as a whiny annoying old man with limited online social skills found out before my friend, so my friend wouldn't have shat his pants or worse.

I agree with this 100%. I used to work in an industry where “Martian testing” (only a Martian would do something like that/read the instructions that way.” But it was life-critical and mission critical software with extremely high public visibility. Sometimes the analysis was done and the risk accepted, sometimes a change was made. That’s a sign of a robust safety culture.

One wonders if there were any “angry old men” involved in the testing of the Boeing 737 engines changes a few years ago  

Wendy P. 

[gowlerk 2,098]

10 minutes ago, wmw999 said:

One wonders if there were any “angry old men” involved in the testing of the Boeing 737 engines changes a few years ago  

Eric has been going after both Aerodyne and more recently RI over his anger about a patent dispute for several years. He is not a disinterested party, he is a man looking for revenge and he is attempting to get it by smearing the companies and people he is angry at. 

[wmw999 2,313]

Tô add to my previous post, there was a saying also where I worked: “In God we trust, everyone else, bring data.” And data really has to be replicatable — in other words, in only one person can torture a certain result, then the testing conditions might be questioned. Data means the testing conditions and results, in video/machine output format, not “I saw.”

Wendy P. 

[wmw999 2,313]

1 minute ago, gowlerk said:

Eric has been going after both Aerodyne and more recently RI over his anger about a patent dispute for several years. He is not a disinterested party, he is a man looking for revenge and he is attempting to get it by smearing the companies and people he is angry at. 

Yep, that too. But if he is, in fact, the independent investigative rigger, then he still needs actual data — not videos and announcements. But one can’t also dismiss his experience out of hand — it’s just as wrong as accepting it out of hand. 
 No one is completely free of secondary motivations, unfortunately.

Wendy P. 

[Unstable 8]

3 hours ago, Quagmirian said:

Something here that no one seems to be mentioning so I will. On the floor, the jumper will rotate upwards pulled by the risers with their feet as a fulcrum and their entire weight resisting the rotation. In freefall, the risers will rotate the jumper around their centre of mass with very little resistance, increasing the bend in the risers and increasing the peeling force on the riser covers. Also, so what if you land with closed riser covers?

I think this is a powerful point that need to be focused on this thread. I can think of several examples where failure modes are imaged by 'pulling slowly on the ground' that do not represent the real forces in a skydive. I think a good datapoint would be to video the openings on this rig and slow it down to study the mechanics of a real-world deployment. 

[JerryBaumchen 1,263]

3 hours ago, Unstable said:

I think this is a powerful point that need to be focused on this thread. I can think of several examples where failure modes are imaged by 'pulling slowly on the ground' that do not represent the real forces in a skydive. I think a good datapoint would be to video the openings on this rig and slow it down to study the mechanics of a real-world deployment. 

Hi Unstable,

And, I think that is something the French should do.

Jerry Baumchen

[gowlerk 2,098]

7 hours ago, Quagmirian said:

Something here that no one seems to be mentioning so I will. On the floor, the jumper will rotate upwards pulled by the risers with their feet as a fulcrum and their entire weight resisting the rotation. In freefall, the risers will rotate the jumper around their centre of mass with very little resistance, increasing the bend in the risers and increasing the peeling force on the riser covers. Also, so what if you land with closed riser covers?

There is a reason container systems are TSOed with drop testing and not static testing. Of course the Talon TSO was issued many years ago and probably was tested with velcro riser covers. The scenario with a total mal where the reserve risers need to pop the covers will always be high speed. The RI rpc with a nearly 3 ft long spring is a very high drag piece of equipment. The force generated is much more than that used in the video. 

I'm sure that by now Sandy, who is retired from the business is aware of this thread. He has come under personal attack by a man who is in a business dispute with him. Since it is unlikely that Sandy is going to dignify this with any sort of reply, which he absolutely should not do, I feel someone should point this out. There are not as many Curvs in the marketplace as some of the other brands. But there are many nonetheless. If there has been a problem in the field with riser covers not opening on reserve rides we would have heard of it by now. This whole thing just reeks of petty jealousy. Vive la France!

[Unstable 8]

1 hour ago, JerryBaumchen said:

Hi Unstable,

And, I think that is something the French should do.

Jerry Baumchen

Agree.

I think back to the videos of the static vs dynamic deployments of the speedbag assembly of the Racer, or the aerodyne freebag, or even the new reserve freebag of the Sigma - the PC applies a force but during the extraction process, the bag is allowed to rock side to side as the various line stows are released and then how the reserve PC escapes through the corner as the last bight still holds on - so wildly different on the ground versus in the air. 

 

So far from this thread, we have see a claim not backed up by any secondary testing, done by someone who we find out has both a business dispute on this rig as well as, in his own words, 

 

Quote

It is exclusively from France since there is no other country where people like me are paid only to find out the design flaws

 

 

[Deyan 36]

On 2/18/2022 at 12:27 PM, Quagmirian said:

Something here that no one seems to be mentioning so I will. On the floor, the jumper will rotate upwards pulled by the risers with their feet as a fulcrum and their entire weight resisting the rotation. In freefall, the risers will rotate the jumper around their centre of mass with very little resistance, increasing the bend in the risers and increasing the peeling force on the riser covers. Also, so what if you land with closed riser covers?

How about you are unconscious and your AAD fires..... because of your body position only ONE raiser cover opens.... How would you like a spinning line twist under your reserve?

[sfzombie13 319]

19 hours ago, gowlerk said:

There is a reason container systems are TSOed with drop testing and not static testing. Of course the Talon TSO was issued many years ago and probably was tested with velcro riser covers.

 

so you're saying that the tso applies even after changing equipment?  i thought they had to get a new tso if they change something.  interesting. 

 

5 minutes ago, Deyan said:

How about you are unconscious and your AAD fires..... because of your body position only ONE raiser cover opens.... How would you like a spinning line twist under your reserve?

you could pick apart one-offs and exceptions all day long and come up with any number of situations where something may or may not work as intended.  that doesn't make any of them likely or valid reasons to change anything.