Forums: Skydiving: Safety and Training:
MARD discussion...

 


Poll: MARD discussion...
I have a Skyhook 67 / 39%
I have another MARD equipped rig 4 / 2%
I want a MARD on my rig 26 / 15%
I Feel Student rigs SHOULD have MARD's 42 / 24%
I Feel Student rigs should NOT have MARD's 13 / 7%
I want to try a MARD system* 22 / 13%
174 total votes
 
fcajump  (D 15598)

Apr 4, 2012, 6:57 AM
Post #1 of 56 (4804 views)
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MARD discussion... Can't Post

*like Vector's traveling demo skyhook triple canopy rig when first introduced.

OK guys, you've had enough to say in the wrong forum and threads... and I know its been talked about before, but there's new folks, new opinions and more time in service for the skyhood, and more MARD's in service/development...

So lets have it, what do you think??
(I'll duck now...) Wink

JW

PS - yes I know... always some option left off Polls... wish the options were editable... sorry.


(This post was edited by fcajump on Apr 4, 2012, 7:11 AM)


DaVinciflies

Apr 4, 2012, 7:04 AM
Post #2 of 56 (4758 views)
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Re: [fcajump] MARD discussion... [In reply to] Can't Post

What about "I don't have a MARD and don't feel the need for one"?


(This post was edited by DaVinciflies on Apr 4, 2012, 7:04 AM)


davelepka  (D 21448)

Apr 4, 2012, 7:10 AM
Post #3 of 56 (4739 views)
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Here's my hang up with the MARD system- the second you change your EPs because you have one, you have taken it from a back up device to a primary device.

If you're willing to chop at 300ft because you have a Skyhook, you're counting on the Skyhook to work or you die.

If you're willing to do anything you wouldn't do without one, you have defeated the purpose. Oh the irony, that Bill Booths product could be the one to prove his theory that for every safety advancement you give jumper, they'll find a way to negate the additional level of safety.

What are MARDS good for? They do seem to limit the amount of 'stuff' that can happen between a cutaway and RSl activated reserve deployment. Quicker deployment means less time for spinning and inducing line twists.

It's also hard to argue with the idea of more altitude. If a MARD can get you under a reserve at 1200ft, while an RSl would have put under canopy at 1000ft, that extra altitude can be used to find and make a suitable landing area.

In the end, it's a narrow margin of improvement over an RSL. Anything a MARD can do, an RSL can do with an extra 200ft, and a human can do with an extra 400ft. While it's hard to argue with an improvement of any kind, I think the MARDs have fallen into a trap where people seem to think they're more than just back up devices, and have it in their mind that they really can cutaway from 300ft if they have to, and that's not really the case.


fcajump  (D 15598)

Apr 4, 2012, 7:44 AM
Post #4 of 56 (4701 views)
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Re: [davelepka] MARD discussion... [In reply to] Can't Post

In reply to:
Here's my hang up with the MARD system- the second you change your EPs because you have one, you have taken it from a back up device to a primary device.

I heard the same argument being used against having AAD's and RSL's. Not saying its invalid, but for me I think it will simply be incorporated into the new way of training/thinking.

I don't think anyone will advocate changing the hard deck to 300', but then I don't hear anyone advocating not pulling because you have an AAD...

But we've seen their use when folks are knocked out, loose track of time, or even simply given up...

I see this as a similar thing... it will be a savior of those who planned to cutaway and pull a reserve with plenty of altitude, but either lost track or had complications getting it done.

JW


JohnRich  (D License)

Apr 4, 2012, 7:58 AM
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There was another feeling I was getting from the previous thread that I wanted to address, but the discussion was shut down there, so I'll throw it in here.

At least one person seemed to be implying that MARD's/Skyhooks are so great that NOT having them on student gear was negligence. And from that, you could imply that the student operations are guilty of killing their students when those students perform low cutaways.

So let's be clear on this. Just because a drop zone doesn't have the latest and greatest parachute inventions does not mean that they are being negligent with the lives of their students. They train the students on how to respond with the gear that they have now, to save their lives in emergencies. The students need to follow those instructions, and not activate cut-aways below 1,000 feet.

It costs money to retrofit a bunch of student gear, and not all drop zones have the dough to go redesigning their gear every time something new comes out. You get to jump what's available now, not what you might like to have in a world where everyone has more money than they need. If you're not comfortable with that, don't jump.

Student gear, and even experienced gear, is often a bunch of compromises. What might solve one problem, often has a downside and can create other problems. How someone chooses to address those compromises and configure their gear is a personal choice. They shouldn't be called negligent just because their decision process is different from yours.

How about an automobile analogy? Do you go out and buy a new high-end car every year in order to have the latest and greatest safety gimmicks that the manufacturers dream up? What, you can't afford that? Well, why not retrofit your existing car? That's too expensive too? Does it mean that you are negligent because you own an older or cheaper car that doesn't have side airbags? Should you be sued if you loan your car to a friend and they run a stop sign and die in a side-impact collision because you chose not to buy a car with side airbags? Is everyone who doesn't drive a Cadillac Escalade an unsafe motorist who is just asking for trouble?


(This post was edited by JohnRich on Apr 4, 2012, 8:06 AM)


Andy9o8  (D License)

Apr 4, 2012, 8:15 AM
Post #6 of 56 (4672 views)
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Re: [davelepka] MARD discussion... [In reply to] Can't Post

In reply to:
Here's my hang up with the MARD system- the second you change your EPs because you have one, you have taken it from a back up device to a primary device.

Not necessarily, in all cases. Maybe it just slightly lowers the deck a jumper uses, down in the basement, between cutting away and just "getting more nylon out" - dumping a reserve into a main has its own perils, as we all know. So in that regard, it's really just about expanding available options a bit.


(This post was edited by Andy9o8 on Apr 4, 2012, 8:19 AM)


fcajump  (D 15598)

Apr 4, 2012, 8:18 AM
Post #7 of 56 (4669 views)
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In reply to:
There was another feeling I was getting from the previous thread that I wanted to address, but the discussion was shut down there, so I'll throw it in here.

At least one person seemed to be implying that MARD's/Skyhooks are so great that NOT having them on student gear was negligence. And from that, you could imply that the student operations are guilty of killing their students when those students perform low cutaways.

So let's be clear on this. Just because a drop zone doesn't have the latest and greatest parachute inventions does not mean that they are being negligent with the lives of their students. They train the students on how to respond with the gear that they have now, to save their lives in emergencies. The students need to follow those instructions, and not activate cut-aways below 1,000 feet.

It costs money to retrofit a bunch of student gear, and not all drop zones have the dough to go redesigning their gear every time something new comes out. You get to jump what's available now, not what you might like to have in a world where everyone has more money than they need. If you're not comfortable with that, don't jump.

Student gear, and even experienced gear, is often a bunch of compromises. What might solve one problem, often has a downside and can create other problems. How someone chooses to address those compromises and configure their gear is a personal choice. They shouldn't be called negligent just because their decision process is different from yours.

How about an automobile analogy? Do you go out and buy a new high-end car every year in order to have the latest and greatest safety gimmicks that the manufacturers dream up? What, you can't afford that? Well, why not retrofit your existing car? That's too expensive too? Does it mean that you are negligent because you own an older or cheaper car that doesn't have side airbags? Should you be sued if you loan your car to a friend and they run a stop sign and die in a side-impact collision because you chose not to buy a car with side airbags? Is everyone who doesn't drive a Cadillac Escalade an unsafe motorist who is just asking for trouble?

On the other hand, negligence law suits have been won when students were injured/killed because the DZ was using out-dated gear that was not up to the accepted industry standard...

At this point a DZ that took this same stand as to why they did not use AAD's on student gear (change of emergency procedures, possible double deployments, cost, maintanence, added education/complexity for the rigger), would be burned by the industry.

(and I have heard those arguments concerning AAD's in the past)

So, by pattern, I guess they may be required on student gear in another 10 years. Wink

JW


Southern_Man  (C License)

Apr 4, 2012, 9:13 AM
Post #8 of 56 (4642 views)
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Re: [fcajump] MARD discussion... [In reply to] Can't Post

So, just a couple of questions....


What other MARDs are out there and available on sport gear besides the skyhook? I am aware some version of the RAX system was recently put on some gear in Europe, but I think that was military only.


What is the proportion of jumps in which the Skyhook does not work as designed (using the cutaway main as a pilot chute) and simply works as an RSL? I've seen anecdotal reports that put this number as high as 10%, I don't know if that is accurate but it seems awfully high to me.


fcajump  (D 15598)

Apr 4, 2012, 9:22 AM
Post #9 of 56 (4638 views)
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In reply to:
What other MARDs are out there and available on sport gear besides the skyhook?

Available - not sure.
In development - Strong and Jerry B are working on designs. Not sure if they are on the market yet, but wanted to leave the option open as I just dunno...

JW


Southern_Man  (C License)

Apr 4, 2012, 10:02 AM
Post #10 of 56 (4614 views)
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In reply to:
In reply to:
What other MARDs are out there and available on sport gear besides the skyhook?

Available - not sure.
In development - Strong and Jerry B are working on designs. Not sure if they are on the market yet, but wanted to leave the option open as I just dunno...

JW

I believe the RAX is Jerry's design (actually an Infinity design) that is freely available to any rig manufacturer that wants it (no patent).

I understand that Eric Fradet has a system but he intends it for military installation only? maybe?

I do not know much at all about the Strong MARD in development.

As I tend not to be an early adopterd I would want to see all of these things on the market for a while before I would be willing to adopt any of them...let other people be the beta testers and find out where the flaws and limitations are...


Southern_Man  (C License)

Apr 4, 2012, 10:05 AM
Post #11 of 56 (4611 views)
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OK, a search has revealed RiggerRob's post on the Strong MARD from PIA 2011--apparently it is intended for tandems. I admit that I don't fully understand all of this, it is all so much simpler with a diagram.:


The reserve also includes a new type of MARD (Main Assisted Reserve Deployment). The "Air Anchor" RSL has a ring on the bottom that slides along the reserve bridle. A 1-ring release system - temporarily - attaches the RSL to the bridle and is held closed by a piece of black flex cable. If the RSL wins the race, it pulls against a (covered) bag-stop-ring and lifts the free-bag.
If the pilot-chute wins the race, the ring (on the bottom of the RSL) slides away from the steel cable and the RSL dis-connects, similar to Socerer and Skyhook.
SEI showed video Air Anchor drop tests.
The reserve bridle configuration is not "frozen" so I suggested sewing on a stiffened (similar to a steering toggle) extra piece of webbing - or at a bare minimum sewing some contrasting thread to remind field riggers where to do the needle fold for the staging loop.
SEI also said that all of their older canopies are compatible with the new system, to ease conversion costs for DZs that already operate Dual Hawks. They have tested SET 400 and SET 366 - as reserves - in various military rigs and will offer them as reserves in the new system.



fcajump  (D 15598)

Apr 4, 2012, 10:10 AM
Post #12 of 56 (4603 views)
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In reply to:
In reply to:
In reply to:
What other MARDs are out there and available on sport gear besides the skyhook?

Available - not sure.
In development - Strong and Jerry B are working on designs. Not sure if they are on the market yet, but wanted to leave the option open as I just dunno...

JW

I believe the RAX is Jerry's design (actually an Infinity design) that is freely available to any rig manufacturer that wants it (no patent).

I understand that Eric Fradet has a system but he intends it for military installation only? maybe?

I do not know much at all about the Strong MARD in development.

As I tend not to be an early adopterd I would want to see all of these things on the market for a while before I would be willing to adopt any of them...let other people be the beta testers and find out where the flaws and limitations are...

Strong was showing it at the 2011 PIA on their new Tandem rig.
From their web site: http://strongparachutes.com/pages/Tandem/force.html
Quote:
We use a simple, yet highly effective main assisted reserve deployment (MARD) system called the Air Anchor. The Air Anchor is part of the RSL so there is no special or extra equipment needed! During a cutaway the Air Anchor activates when the main canopy has more drag than the departing reserve pilot chute reducing time and altitude lost by as much as 50%. With no complicated rigging required the Air Anchor is simply the best safety system available!


Thanks for the update on the others.
JW


councilman24  (D 8631)

Apr 4, 2012, 1:12 PM
Post #13 of 56 (4548 views)
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Re: [Andy9o8] MARD discussion... [In reply to] Can't Post

Remember, having a MARD does NOT change the allowable opening time/distance under TSO testing. So you can have a MARD that doesn't make anything better.

Current TSO Limits Canopies with max weight up to 250. For Breakaway. 5 secs or 300 ft. Measured from pack opening. For over 250 it goes up 0.01s and 1ft per pound.

WITH an RSL must be open within these limits from time of BREAKAWAY.

Proposed TSO standard not yet official. RSL breakaway test change to pack opening.

If MARD equiped 16 additional tests (4 each) with stable, spinning forward, backward, and baglock after freefall tests.

MAX Altitude/Time to open do NOT change.

So, should the cutaway decision altitude change? NIMO A RSL or MARD will help with the cutaway not reserve pull/delayed reserve pull incidents which aren't uncommon, even with experienced jumpers. A MARD will help with the potential fatality that waited too long to cutaway. Would/could I change my cutaway versus more nylon decision based on a MARD? No. First altitude is likely changing fast enough that no MARD/MARD decision points are likely passed quickly. In addition cutaway or not decision point should be higher than the MAX time done under TSO testing. TSO testing was probably best case. So you need to cutaway higher than 300' to ensure rig functions within testing limits. RSL might get pack open sooner. MARD may get you more flight time but relying on it to get it open sooner and changing decision altitudes is at best a paper exercise. What it MAY do is save the folks that have already passed all the decision altitudes and still cutaway. Or forced to by low incident/change in main.

So far for me advantages of MARD don't outway complexity.

Of course I haven't bought new gear other than AAD for 15 years.Wink


JerryBaumchen  (D 1543)

Apr 4, 2012, 1:20 PM
Post #14 of 56 (4544 views)
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Re: [Southern_Man] MARD discussion... [In reply to] Can't Post

Hi Southern,

Quote:
the RAX is Jerry's design (actually an Infinity design)

I'm glad that you added that last part.

It is actually Kelly Farrington's design ( yea, I know he owns Velocity Sports ).

The concept & the original work on the RAX was entirely done by Kelly; and it is very important that he ( and only he ) get the necessary recognition for his work.

Quote:
Jerry B are working on designs
IMO all of my work is completed. It is now up the any mfr to do their work to include, should they choose to do so.

Quote:
freely available to any rig manufacturer that wants it (no patent).

When Kelly & I first started working on the RAX, this was the one criteria that we both insisted upon.

JerryBaumchen

PS) And I will freely send out RAX mockups to anyone who wants to see one. I only ask that it be returned; some have not. Mad


skydiverek  (C 952)

Apr 5, 2012, 3:59 AM
Post #15 of 56 (4437 views)
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Re: [fcajump] MARD discussion... [In reply to] Can't Post

MARDS that I know of:

Skyhook (UPT)
RAX (Kelly Farington)
Interlock (Eric Fradet)
DRX (Mirage)
LES (Basik)
DRD (SWS Rigs)


(This post was edited by skydiverek on Apr 5, 2012, 4:42 AM)


Skyper

Apr 5, 2012, 4:24 AM
Post #16 of 56 (4422 views)
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Re: [fcajump] MARD discussion... [In reply to] Can't Post

Hereby my answer:

I DON'T HAVE MARD AND I DON'T WANT IT.

I think student's rigs should be kept clean from MARD/alike things.

(This post was edited by Skyper on Apr 5, 2012, 4:30 AM)


Southern_Man  (C License)

Apr 5, 2012, 4:33 AM
Post #17 of 56 (4415 views)
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In reply to:
MARDS that I know of:

Interlock (Eric Fradet)
DRX (Mirage)
LES (Basik)
DRD (SWS Rigs)

Are these available on sport rigs?


skydiverek  (C 952)

Apr 5, 2012, 4:41 AM
Post #18 of 56 (4407 views)
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Re: [Southern_Man] MARD discussion... [In reply to] Can't Post

In reply to:
In reply to:
MARDS that I know of:

Interlock (Eric Fradet)
DRX (Mirage)
LES (Basik)
DRD (SWS Rigs)

Are these available on sport rigs?

Interlock (Eric Fradet): military
DRX (Mirage): sport (secret option for selected customers ;-) )
LES (Basik): sport (used to be?, not any more)
DRD (SWS Rigs): military


(This post was edited by skydiverek on Apr 5, 2012, 4:43 AM)


fcajump  (D 15598)

Apr 5, 2012, 5:07 AM
Post #19 of 56 (4390 views)
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Re: [Skyper] MARD discussion... [In reply to] Can't Post

In reply to:
Hereby my answer:

I DON'T HAVE MARD AND I DON'T WANT IT.

I think student's rigs should be kept clean from MARD/alike things.

Could you please add information to your profile so that we can more accuratly place your opinion within the context of your experience and time-in-sport?
Thanks,
JW Smile


Skyper

Apr 5, 2012, 5:27 AM
Post #20 of 56 (4383 views)
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why didn't you provide an option "I don't use MARD" as an possible answer to this question?

Edit: and you can place your opinion about my opinion whereever you want.

(This post was edited by Skyper on Apr 5, 2012, 5:29 AM)


fcajump  (D 15598)

Apr 5, 2012, 5:37 AM
Post #21 of 56 (4374 views)
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In reply to:
why didn't you provide an option "I don't use MARD" as an possible answer to this question?

Edit: and you can place your opinion about my opinion whereever you want.

Oversite (honest... as mentioned in my edited original post... when I realised it, it would not let me edit the poll options.)

Just curious if your opinion was one of a young student or of a seasoned verteran of the belly-wart vintage, or otherwise. Just wanting to understand the backgrounds of the people and their opinion. As to your, I respect it and wish you well.

JW


billbooth  (D 3546)

Apr 5, 2012, 5:50 AM
Post #22 of 56 (4368 views)
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Re: [skydiverek] MARD discussion... [In reply to] Can't Post

For a point of reference: Skyhooks have been on the market for 10 years now, and are installed on over 15,000 civilian and military rigs worldwide.


Southern_Man  (C License)

Apr 5, 2012, 11:01 AM
Post #23 of 56 (4324 views)
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Re: [skydiverek] MARD discussion... [In reply to] Can't Post

In reply to:
Interlock (Eric Fradet): military
DRX (Mirage): sport (secret option for selected customers ;-) )
LES (Basik): sport (used to be?, not any more)
DRD (SWS Rigs): military

I wonder how many DRX are out there in the field?

Any idea why the LES wsa introduced and then withdrawn? Of maybe it wasn't introduced?


Deyan  (D 322)

Apr 5, 2012, 11:32 AM
Post #24 of 56 (4312 views)
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In reply to:

Current TSO Limits Canopies with max weight up to 250. For Breakaway. 5 secs or 300 ft. Measured from pack opening. For over 250 it goes up 0.01s and 1ft per pound.

4.3.6 Functional Test (Normal Pack All Types):
For all 4.3.6 tests the maximum allowable opening time for
parachute canopies with a maximum operating weight of 250 lb (113.4 kg) or less, is 3 s from the
moment of pack opening.


JerryBaumchen  (D 1543)

Apr 5, 2012, 11:33 AM
Post #25 of 56 (4312 views)
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Hi Bartek,

Quote:
MARDS that I know of: DRD (SWS Rigs)

This is a RAX System. I have no idea of how it became something called 'DRD.' Might be some Ukraine translation.

It is a RAX System.

JerryBaumchen


councilman24  (D 8631)

Apr 5, 2012, 3:10 PM
Post #26 of 56 (2825 views)
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Re: [Deyan] MARD discussion... [In reply to] Can't Post

I'm on my phone. But go look at breakaway testing. It keeps 300' but adds +2 second to the 4.3.6 requirements since its subterminal. 4.3.6.2 last sentence. It's in the car.


(This post was edited by councilman24 on Apr 5, 2012, 3:19 PM)


NWPoul  (D 178119)

Apr 5, 2012, 9:54 PM
Post #27 of 56 (2778 views)
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Re: [skydiverek] MARD discussion... [In reply to] Can't Post

In reply to:
Interlock (Eric Fradet): military
DRX (Mirage): sport (secret option for selected customers ;-) )
LES (Basik): sport (used to be?, not any more)
DRD (SWS Rigs): military
DRD from SWS Rigs is avaible to order for sport rig "SWS Fire"


skydiverek  (C 952)

Apr 6, 2012, 3:03 AM
Post #28 of 56 (2756 views)
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Re: [NWPoul] MARD discussion... [In reply to] Can't Post

Thank you for all the corrections and clarification!


Deyan  (D 322)

Apr 7, 2012, 5:22 AM
Post #29 of 56 (2697 views)
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In reply to:
I'm on my phone. But go look at breakaway testing. It keeps 300' but adds +2 second to the 4.3.6 requirements since its subterminal. 4.3.6.2 last sentence. It's in the car.

You are right Terry and I was wrong.

I knew that 2 seconds delay after cutaway is allowed, but I was not aware that you can add those seconds to the total time when using RSL.


jsaxton  (D 26818)

Apr 7, 2012, 8:55 PM
Post #30 of 56 (2625 views)
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Re: [fcajump] MARD discussion... [In reply to] Can't Post

where is the option for I don't want one, I'd rather not introduce any additional complexity in my equipment?


eric.fradet

Apr 8, 2012, 4:25 AM
Post #31 of 56 (2595 views)
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Re: [Southern_Man] MARD discussion... [In reply to] Can't Post

Any idea why the LES wsa introduced and then withdrawn? Of maybe it wasn't introduced?
__________________________________________________
I can answer this one since I designed the LES : it was withdrawn because MARD system was found unsafe in sport rigs, what was the case in 96, and it is still true in 2012 (some manufacturers should also not offer it to sale), as I said it could be useful only in case you cuttaway in between 200 feet and 300 feet above the ground ! not a situation you will see in an entire life on a drop zone, besides of that there is a lot of situation where MARD can kill you ! sometime to make the sport safer, you have to make it less complicated


ShcShc11  (A 15638)

Apr 8, 2012, 8:34 AM
Post #32 of 56 (2557 views)
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Re: [eric.fradet] MARD discussion... [In reply to] Can't Post

In reply to:
Any idea why the LES wsa introduced and then withdrawn? Of maybe it wasn't introduced?
__________________________________________________
I can answer this one since I designed the LES : it was withdrawn because MARD system was found unsafe in sport rigs, what was the case in 96, and it is still true in 2012 (some manufacturers should also not offer it to sale), as I said it could be useful only in case you cuttaway in between 200 feet and 300 feet above the ground ! not a situation you will see in an entire life on a drop zone, besides of that there is a lot of situation where MARD can kill you ! sometime to make the sport safer, you have to make it less complicated

"is still true in 2012"
even the skyhook?

Cheers!


Deyan  (D 322)

Apr 8, 2012, 10:08 AM
Post #33 of 56 (2546 views)
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In reply to:
"is still true in 2012"
even the skyhook?

Cheers!

What makes you think that Skyhook is an exception ?


ShcShc11  (A 15638)

Apr 8, 2012, 3:34 PM
Post #34 of 56 (2506 views)
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Re: [Deyan] MARD discussion... [In reply to] Can't Post

In reply to:
In reply to:
"is still true in 2012"
even the skyhook?

Cheers!

What makes you think that Skyhook is an exception ?

Well the poster's assertion is that all MARDs are unsafe even in 2012. I'm assuming he is including the skyhook too?

If that is so, are there any tangible real-life examples (or better yet, statistics) that demonstrate that it is unsafe? As the good ol' folks at ChutingStar once said: "not necessary, but highly recommended". Smile



Hugs & Cheers!
Shc


Southern_Man  (C License)

Apr 8, 2012, 8:13 PM
Post #35 of 56 (2460 views)
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Re: [eric.fradet] MARD discussion... [In reply to] Can't Post

In reply to:
Any idea why the LES wsa introduced and then withdrawn? Of maybe it wasn't introduced?
__________________________________________________
I can answer this one since I designed the LES : it was withdrawn because MARD system was found unsafe in sport rigs, what was the case in 96, and it is still true in 2012 (some manufacturers should also not offer it to sale), as I said it could be useful only in case you cuttaway in between 200 feet and 300 feet above the ground ! not a situation you will see in an entire life on a drop zone, besides of that there is a lot of situation where MARD can kill you ! sometime to make the sport safer, you have to make it less complicated

Hi Eric,

Thanks for sharing. Was the LES some version of your interlock system or is that a different system?

What was found to be unsafe about it in sport rigs?


eric.fradet

Apr 9, 2012, 2:00 AM
Post #36 of 56 (2439 views)
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Re: [Southern_Man] MARD discussion... [In reply to] Can't Post

Besides the fact I do not like the idea for any sport rig to use any MARD, (in my mind MARD is restricted to the soldiers jumping at 1000 foot high, who are the only skydivers paid to be kill, anyways)
5 reasons to not use any MARD (in fact they are more but it should be enough to convince people)
1) Increasing entanglement on any Type of main horse shoe malfunction
On a MARD equipped rig, the chance having your camera helmet entangled by the reserve travelling on his way is duplicated when you cutaway, in those days everyone jump a camera.
Also if only the non-RSL riser is entangled, the RSL riser will leave and open your reserve container, chance on entanglement is higher.

the MARD may also increase the probability of a main and reserve entanglement after a cutaway, in any type of horseshoe malfunction like foot (feet) in the main lines, main pilot chute trapped in the arm or foot, or main container open while main pc still in his pocket, The situation of a horseshoe (premature container opening with PC still in pouch) is worth looking at to get the picture :

Any type of partial or total malfunction will look like these two little pictures which show the differences in between having a skyhook or not.

Pic 1 shows a PC (without a MARD) trying to blow by the cutaway main that is still attached to a jumper via a stuck pc.
Pic 2 shows the MARD trying to blow by the cutaway main that is still attached to a jumper via a stuck pc.

If the reserve pc with the MARD inflates, it is likely that the reserve will find clear air to inflate in, but not if the reserve pc goes through the lines of the main or something similar.

If the reserve pc with the MARD does not catch air immediately, and is still attached to the MARD wraps the trailing main, then I think that a main-reserve entanglement is almost a certainty. The remaining length of the reserve bridle line may provide enough drag for the reserve canopy to come out of the reserve bag, but maybe not.
You can also get more slack in the reserve deployment (from the MARD point of attachment to the reserve risers) that will allow the reserve (bag and or lines) to flap around and become entangled with the trailing main. At best you could hope for the drag on the reserve lines to pull the reserve canopy out of the bag, even if the bag is attached someplace along the trailing main.
I think this is a failure mode of the MARD that has not been tested, not been explained and kind of glossed over. (I certainly do not recommend asking test jumpers to test this either.)

2)Main bag lock hitting the reserve ( I did experimented it myself) .
All bag locked mains will not miss the reserve canopy, especially when it is a Sigma Tandem., their tandem reserve opens in deep brakes, and therefore doesn't get out of the way as well as a "normally" braked canopy.
Also with a small reserve, there is some damage or entanglement potential issue, especially to have the main lines wrapped around the reserve ones.

3) twisted lines reserve due to the main spinning malfunction momentum :
All very experienced skydivers who experimented a few of this type of scenario have already disconnected their Skyhook (including sponsored team by UPT like world champion Babylon Team and French National Vertical Formation Skydiving team do not use it because of that)
Read this one : it is the worst case I know, but I have other very similar scenario too : A very experienced jumper using a skyhook had a malfunction on a Velocity that had him spinning into line twists while the canopy was spinning. The resulting cutaway with a skyhook had him entangled in the freebag and bridle, he sorted it out but was nearly choked out by the reserve risers caught under his chin. It produced some nasty rash. Severe spinning around your Y axis while spinning violently doesn't seem to be covered on the videos that I have seen

4) increase of reserve shock opening
There are, scenarios where an open canopy can be cutaway and act as a super pilotchute while the jumper is still at terminal.
1. The cutaway handle is accidently pulled on exit or in freefall, the jumper deploys the main, the riser covers hold long enough for the canopy to come out of the bag and partially inflate before separating from the harness.
2. The jumper deploys the main, has a hesitation, goes for the cutaway handle as the pilotchute lifts off, cuts away just as the canopy comes out of the bag. This is a relatively common malfunction.
3. The jumper experiences a baglock. Just on cutaway the canopy comes out of the bag.
In these scenarios the jumper has not been decelerated by the main but it will be at least partially inflated as it lifts off. If there is a skyhook it will act as a super pilotchute with the risk of a catastophically hard opening.
Many people think that once the resreve is out of the bag the speed of the opening is determined only by the slider. The slider is critical for any opening but so is the pilotchute. UPT knows this so their drogues collapse on lift off so as to have just the right amount of snatch to lift the bag at optimum speed. If your kill line shrinks on your sport rig not only do you get slower bag lift off you get slower inflation.
A big pilotchute gives a harder opening because the bag is more rapidly decelerated. At the moment the canopy comes out of the bag the speed difference between the jumper and the canopy will be higher and therefore the load on the lines will be higher. That means the initial snatch will be harder but force on the lines also contributes to the next stage of canopy inflation.
Lets say standard bag lift off takes one third of a second. That suggests the bag is travelling at about 45 feet per second slower than the jumper. 135 ft/s vs 180 ft/s.
A fully open canopy with a suspended jumper has a descent rate of about 15 feet per second. A cutaway canopy with only a reserve freebag hanging under it will have a descent rate somewhere between 135 ft/s and 15ft/s depending on the degree of inflation. It d doesn't need to be inflated much to increase the speed difference between the jumper and the bag by a factor of 2 or 3 and possibly as much as 6 compared to a standard pilotchute.
Surely this creates the possibility of a severely hard opening. The prospect of superhard skyhook openings has not been fully investigated.

5) Short reserve bridle
Some manufacturers have shorten the reserve bridle by 4 feet to make the system work better! This is just as insane than tacking the system with a 4 pounds of resistance cord to the reserve container !
They forgot that there was a good reason to decide in the past to come up with the 16 feet long reserve bridle, like they also forgot that there was a good reason to have a hesitator loop configuration to secure the bridle and holds the reserve bag, with a bite of the reserve bridle to stage/sequence the reserve opening, by locking the container closed under full reserve bridle extension.
For sure we build up devices to make the skydiver a better idiot instead to educate him .. So, I donít think that there is anything good with putting out a (necessarily) flawed system specially as long the truth is not out there about the weaknesses of the system so people are not informed, having no responsible decisions about whether to use it or not. Downplaying the dangers doesnít do anyone any good.

I think that problems will always exist in any MARD, there is no perfect system. Furthermore, it is a system which is designed to make up for user stupidity, and therefore could be eliminated if people werenít being stupid. Still, people want it. Never mind that it could kill them, or that gear is very safe when used appropriately without it. They still want it.
UPTís story that there have been thousands of Skyhook deployments with no other problems misses the point: that people should fully understand their gear, how it works and how it may fail, so that they can take responsibility for their own safety. They should not be told a fairy tale of perfection, as if skydiving could be made completely safe by better gear.
Too much safety devices kill the safety !
For sure we build up devices to make the skydiver a better idiot instead to educate him .. So, I donít think that there is anything good with putting out a (necessarily) flawed system specially as long the truth is not out there about the weaknesses of the system so people are not informed, having no responsible decisions about whether to use it or not. Downplaying the dangers doesnít do anyone any good.

I think that problems will always exist in any MARD, there is no perfect system. Furthermore, it is a system which is designed to make up for user stupidity, and therefore could be eliminated if people werenít being stupid. Still, people want it. Never mind that it could kill them, or that gear is very safe when used appropriately without it. They still want it.
UPTís story that there have been thousands of Skyhook deployments with no other problems misses the point: that people should fully understand their gear, how it works and how it may fail, so that they can take responsibility for their own safety. They should not be told a fairy tale of perfection, as if skydiving could be made completely safe by better gear.
Too much safety devices kill the safety !
Attachments: MARD issue.odt (69.2 KB)


GGGGIO  (D 14774)

Apr 12, 2012, 7:15 AM
Post #37 of 56 (2301 views)
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Re: [DaVinciflies] MARD discussion... [In reply to] Can't Post

+1


pchapman  (D 1014)

Apr 19, 2012, 7:24 AM
Post #38 of 56 (2177 views)
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Re: [eric.fradet] MARD discussion... [In reply to] Can't Post

For those who can't easily open Eric's .odt Open Doc file, here's a conversion to PDF, even if this is a bit late to the conversation. It sketches his thoughts on deploying a reserve past a horseshoe, MARD and no MARD.
Attachments: MARD20issue.pdf (52.4 KB)


JohnSherman  (D 2105)

Apr 20, 2012, 9:03 AM
Post #39 of 56 (2096 views)
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Re: [councilman24] MARD discussion... [In reply to] Can't Post

Quote:
It keeps 300' but adds +2 second to the 4.3.6 requirements since its subterminal. 4.3.6.2 last sentence.

Sorry Councilman but those numbers are not additive. The opening time is 3 seconds or 300 feet from activation, RSL or no RSL. I know some manufacturers have made the interpretation that it allows 5 seconds but it is an intentional distortion so that they could get their rigs certified.

I sat on the committee that wrote the rule and it was never intended to be interpreted this way. If you don't have an RSL and are trying to get a reserve pull within 2 seconds after cutaway you had better be fast. The non-additive allowance was provided to allow for testing and certification without an RSL.
This has apparantly been clairfied in the latest revision of TS-135


councilman24  (D 8631)

Apr 20, 2012, 10:53 AM
Post #40 of 56 (2068 views)
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Re: [JohnSherman] MARD discussion... [In reply to] Can't Post

If that's true John the language was not written to reflect that position. It is changed in the new one. It's three seconds from pack opening, rsl or not.


JohnSherman  (D 2105)

Apr 20, 2012, 1:02 PM
Post #41 of 56 (2056 views)
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Re: [councilman24] MARD discussion... [In reply to] Can't Post

Quote:
If that's true John the language was not written to reflect that position. It is changed in the new one. It's three seconds from pack opening, rsl or not.

I would agree that the language was poor. However, Everyman Jack, who makes rigs, was on that committee and all knew that the rule was 3 seconds. It was 3 seconds before that version and is 3 seconds in the next version. There was never any discussion about raising it to a longer time.
I don't buy the excuse of mis-interpretation. I don't read the language that way.


councilman24  (D 8631)

Apr 20, 2012, 2:34 PM
Post #42 of 56 (2031 views)
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Re: [JohnSherman] MARD discussion... [In reply to] Can't Post

I didn't have it in front of me when I replied earlier. I do now.

I don't know any other way to read the sentence.

"Breakaway Drop Tests: Eight drips shall be made by a person weighing not more than the maximum operating weight by breaking away from an open and normally functioning main parachute canopy with a vertical velocity of less than 20 FPS (6.1 m/s) at the time of the breakaway and actuating the reserve pack within 2 s of the breakaway. If a reserve static line is part of the assembly, no less than 4 of the breakaway drops shall be made with the reserve static loin actuating the reserve pack. The parachute canopy must be functionally open withing the time +2 s, or altitude, obtained in 4.3.6 from the time of breakaway."
emphasis added

Sure looks like it gives both the jumper and the RSL 2 seconds to open the reserve pack and then the 3 seconds for the normal opening requirement. Since no standard is given for the first case the last sentence must apply to both manual and RSL. "...time +2 s.." sure looks additive to me.Angelic And yes this would effectively allow a reserve to take 5 secs to open using an RSL because pack opening is fractions of a second after breakaway.

I agree this is not what we want to measure and hence the changes in TS-135 to measure both from the pack opening and apply 3 sec.

But we've hijacked the thread and its time to go pick up the kids.Wink


skydiverek  (C 952)

Jan 8, 2013, 1:53 PM
Post #43 of 56 (1492 views)
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Re: [NWPoul] MARD discussion... [In reply to] Can't Post

In reply to:
In reply to:
Interlock (Eric Fradet): military
DRX (Mirage): sport (secret option for selected customers ;-) )
LES (Basik): sport (used to be?, not any more)
DRD (SWS Rigs): military
DRD from SWS Rigs is avaible to order for sport rig "SWS Fire"

Looks like it uses Collins Lanyard licensed from UPT, correct?

http://www.swsrigs.com/...s/fire/features/drd/




ChrisD  (No License)

Jan 8, 2013, 2:28 PM
Post #44 of 56 (1475 views)
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Re: [pchapman] MARD discussion... [In reply to] Can't Post

In reply to:
For those who can't easily open Eric's .odt Open Doc file, here's a conversion to PDF, even if this is a bit late to the conversation. It sketches his thoughts on deploying a reserve past a horseshoe, MARD and no MARD.

I'm stareing at picture #2 and I'm a little confused, Don't we "complete the sequence," in a horseshoe by releasing the PC? As our first step? And I get the point you guys are trying to make, esp about the UPT Reserve PC, but I have yet to see any PC pointing downward?? (Ya I have seen burbiling PC's, but never pointing downward?)

Someone help me out here?
C


JerryBaumchen  (D 1543)

Jan 9, 2013, 11:58 AM
Post #45 of 56 (1365 views)
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Re: [skydiverek] MARD discussion... [In reply to] Can't Post

Hi Bartek,

Quote:
Looks like it uses Collins Lanyard licensed from UPT, correct?

It has been a few years since I have looked at/read the licensing contract ( which was to be with a 'Parachute Patents' organization ) but it had no provisions for licensing the lanyard only.

The SkyHook licensing contract included the lanyard; at least in the copy that I was given.

JerryBaumchen


pchapman  (D 1014)

Jan 9, 2013, 10:23 PM
Post #46 of 56 (1261 views)
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Re: [ChrisD] MARD discussion... [In reply to] Can't Post

In reply to:
I'm stareing at picture #2 and I'm a little confused, Don't we "complete the sequence," in a horseshoe by releasing the PC? As our first step? And I get the point you guys are trying to make, esp about the UPT Reserve PC, but I have yet to see any PC pointing downward?? (Ya I have seen burbiling PC's, but never pointing downward?)
Someone help me out here?
C

To answer one question, I have seen Vector PCs in a burble be completely inverted or in any attitude, even for a single jumper (not just an AFF 3-person burble). This was for a Vector PC on a main canopy. Maybe it didn't launch quite as well as on a tightly packed reserve, but still this shows it is possible -- see my video at http://blip.tv/...pilot-chutes-3507191.


As for the 2 drawings by Eric Fradet:

I don't know Eric's exact line of thinking but this is what I see:

-- He's talking about the type of horseshoe you can't clear from its entanglement, or you don't notice in time. If you do clear it, then you don't have a horseshoe any more. Great.

-- Now say that you still have the horseshoed main, cut it away, but it is trailing off you at some location. If the reserve PC catches air properly, then it doesn't matter whether you have a Skyhook; the reserve PC is doing the job and hopefully will clear the trailing mess. Everyone takes their chances equally.

-- But he says that if the reserve PC burbles for a moment and doesn't catch air, now instead of a trailing mess and a nearby reserve PC trying to catch air (dangerous enough), you also have the Skyhook lanyard still connecting the flapping, trailing risers, to your reserve bridle.

So now you are pulling the reserve bridle in towards the trailing main canopy mess, especially just as the main risers are cutaway from your shoulders and whip back to wherever the entangled main is trailing.

(Assuming the drag on the risers is enough to peel all that Skyhook RSL velcro in the first place. That has been questioned for some low drag mals like baglocks. Manually clearing risers away by hand has been suggested.)

Is the connection between the main risers and the reserve bridle enough to actually drag the reserve pilot chute into the trailing mess? Will even just yanking some reserve bridle towards the mess be enough to cause problems?

I'm not sure yet either way, but Eric seems to think so, and asks whether any testing has been done to show what the truth really will be for that scenario.


gregpso  (Student)

Jan 10, 2013, 7:00 AM
Post #47 of 56 (1203 views)
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Re: [billbooth] MARD discussion... [In reply to] Can't Post

In reply to:
For a point of reference: Skyhooks have been on the market for 10 years now, and are installed on over 15,000 civilian and military rigs worldwide.

I rest my case 10 years now... proven technology. way to go Bill !!


(This post was edited by gregpso on Jan 10, 2013, 7:03 AM)


piisfish

Jan 10, 2013, 7:17 AM
Post #48 of 56 (1195 views)
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Re: [fcajump] MARD discussion... [In reply to] Can't Post

I don't have one, and don't want one for now.


JohnSherman  (D 2105)

Jan 10, 2013, 10:38 AM
Post #49 of 56 (1162 views)
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Quote:
I'm stareing at picture #2 and I'm a little confused, Don't we "complete the sequence," in a horseshoe by releasing the PC? As our first step? And I get the point you guys are trying to make, esp about the UPT Reserve PC, but I have yet to see any PC pointing downward?

The pilot chute is pointing downward because the "Skyhook" is "Hooked" to the reserve bridle at just above the halfway point. The loading from the horseshoed main canopy is to this point and is greater than the response of the reserve pilot chute. The reserve pilot chute has not had chance to orientate itself. However, it is still dragging but in the wrong way. There are numerous videos where this may be observed. If I remember correctly it is observable on the original promo video.


ChrisD  (No License)

Jan 10, 2013, 1:04 PM
Post #50 of 56 (1122 views)
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Re: [JohnSherman] MARD discussion... [In reply to] Can't Post

In reply to:
Quote:
I'm stareing at picture #2 and I'm a little confused, Don't we "complete the sequence," in a horseshoe by releasing the PC? As our first step? And I get the point you guys are trying to make, esp about the UPT Reserve PC, but I have yet to see any PC pointing downward?

The pilot chute is pointing downward because the "Skyhook" is "Hooked" to the reserve bridle at just above the halfway point. The loading from the horseshoed main canopy is to this point and is greater than the response of the reserve pilot chute. The reserve pilot chute has not had chance to orientate itself. However, it is still dragging but in the wrong way. There are numerous videos where this may be observed. If I remember correctly it is observable on the original promo video.

But isn't the skyhook connected to the right main riser?? And in this picture the risers are still attached??? Let me get this straight, cause im having a brain fart here??? The risers have the power to "outrace" a pilot chute??? So what yoour saying is that the skyhook bridal under these conditions can actually wrap around the trapped main mess and hold down the PC?? As things that don't release correctly have been shown to do...
C


ChrisD  (No License)

Jan 13, 2013, 8:19 AM
Post #51 of 56 (569 views)
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Re: [ChrisD] MARD discussion... [In reply to] Can't Post

I just want to fully understand picture # 2?

So your saying that the container opened, the canopy is in the bag, but the pc bridal is still in the boc pouch but the lines extended fully and then you cutaway?
C


Scrumpot  (D License)

Jan 13, 2013, 8:54 AM
Post #52 of 56 (558 views)
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Re: [gregpso] MARD discussion... [In reply to] Can't Post

In reply to:
I rest my case 10 years now... proven technology. way to go Bill !!

I thought that you had requested your account / identity on here be closed, and that you were "done". Crazy


skydiverek  (C 952)

Jan 13, 2013, 12:11 PM
Post #53 of 56 (506 views)
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Re: [skydiverek] MARD discussion... [In reply to] Can't Post

In reply to:
In reply to:
In reply to:
Interlock (Eric Fradet): military
DRX (Mirage): sport (secret option for selected customers ;-) )
LES (Basik): sport (used to be?, not any more)
DRD (SWS Rigs): military
DRD from SWS Rigs is avaible to order for sport rig "SWS Fire"

Looks like it uses Collins Lanyard licensed from UPT, correct?

http://www.swsrigs.com/...s/fire/features/drd/


English article:

http://www.swsrigs.com/...s/fire/features/drd/




JohnSherman  (D 2105)

Jan 13, 2013, 3:39 PM
Post #54 of 56 (474 views)
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Re: [ChrisD] MARD discussion... [In reply to] Can't Post

Quote:
I just want to fully understand picture # 2?

So your saying that the container opened, the canopy is in the bag, but the pc bridal is still in the boc pouch but the lines extended fully and then you cutaway?
C

In picture #2 the black risers which are attached to the shoulders of the jumper are the reserve risers with the reserve bag above the jumper. The main (in red) risers and most of the main are out of the sketch above the jumper. The main pilot chute is stuck in the pouch.


ChrisD  (No License)

Jan 13, 2013, 4:26 PM
Post #55 of 56 (461 views)
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Re: [JohnSherman] MARD discussion... [In reply to] Can't Post

In reply to:
Quote:
I just want to fully understand picture # 2?

So your saying that the container opened, the canopy is in the bag, but the pc bridal is still in the boc pouch but the lines extended fully and then you cutaway?
C

In picture #2 the black risers which are attached to the shoulders of the jumper are the reserve risers with the reserve bag above the jumper. The main (in red) risers and most of the main are out of the sketch above the jumper. The main pilot chute is stuck in the pouch.

THANKS JOHN, ERR., I mean Mr. Sherman Smile

So the departing main risers have the ability to, as Bill Booth points out, "outrace" the pilot chute? And enough drag to pull the reserve pin which as I understand it is about 22 Lbs..? And where exactly in the picture #2 is the skyhook sewn into the bridal? No wonder UPT didn't do the horseshoe test?? Can anyone get those guys in CA,???>>>That show where they test things, I forget the name...I want to make a dummy, fill it full of radio servos, make a horseshoe mal, push it out of an 182, and in fact find out if a skyhook rig is more or less of a concern than a regular horseshoe?? And test this in CA. I have a really big back yard, no worries about drop'n something on someone.
C


ChrisD  (No License)

Jan 14, 2013, 4:06 AM
Post #56 of 56 (413 views)
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Re: [eric.fradet] MARD discussion... [In reply to] Can't Post

In reply to:
1) Increasing entanglement on any Type of main horse shoe malfunction
On a MARD equipped rig, the chance having your camera helmet entangled by the reserve travelling on his way is duplicated when you cutaway,

PC still in pouch) is worth looking at to get the picture :

that people should fully understand their gear, how it works and how it may fail, so that they can take responsibility for their own safety. They should not be told a fairy tale of perfection, as if skydiving could be made completely safe by better gear.
Too much safety devices kill the safety !

Speaking of "Fairy Tale":

Isn't picture #2 a lie at worst, or at best ignorance of how this thing actually works?

The skyhook, hook is about 5 feet from the end of the reserve pilot chute. His picture number 2 clearly shows the reserve pc in the middle being pulled upward! But we all know the reserve pc is at the very end of its own bridle, right??? But that is NOT what this picture shows!

But yet to make this fantasy work the author states that the now free main risers can violently pull up the reserve pc? And yet the main is still in the bag?????

If your going to bash the skyhook with this elaborate fantasy and attempt to mislead a gullible public, you have better go back to the drawing board and make up better pictures, or at least fully understand how something works before you bash it.

You have also is this elaborate fantasy have yet to explain how a skyhook rig is less or more of an issue in a hypothetical entanglment?

Speaking yet of the worst possible type of high speed horseshoe...the main pc is stuck and you ignore any attempt at proper procedure to pull it out of its bag? Next we have a main that is disloged via a pin bump??? But the main lines pay out just enough that we have a bag lock?? And we have a main bridle that dosen't move or release either??? But yet we have enough resistance on a pair of cutaway risers to drag the reserve pc???

You had better go back to the bashing drawing board or at least fully how something works before you start drawing incomplete pictures???

Just my 2 cents from LA.
C

Just a little tired so please excuse if I have crossed some line with language, it's 2 am and this is keeping me awake!Unsure



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