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Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories)

 

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BKR

Oct 1, 2008, 8:01 AM
Post #26 of 107 (4163 views)
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Re: [skysurfcam] Skyhook Activation Stories [In reply to] Can't Post

Which rigs are banned in France?


karlm

Oct 1, 2008, 9:26 AM
Post #27 of 107 (4118 views)
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Re: [skysurfcam] Skyhook Activation Stories [In reply to] Can't Post

Nothing but unabashed applause from here. Nice to see a manufacturer with the balls to call a schoolyard bully like Fradet out.

Expect to see him finding a reason why your rigs are banned in france without a costly, pointless refit...Unsure

C.
To clarify things, I no longer work for that manufacturer. Smile

The retrofit was designed by Eric or the safety committee and then when riggers and jumpers had it done, they ran into further red tape .... Unsure

If you need more clarification on the status of that container in France, get with the manufacturer.


airtwardo  (D License)

Oct 1, 2008, 9:31 AM
Post #28 of 107 (4115 views)
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Re: [mnealtx] Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories) [In reply to] Can't Post

In reply to:
In reply to:
I'm surely interested in Pro's and Con's of the M.A.R.D. but only know about 'here say' no real proof. So help me out here, here's a scenario that i 'heard' about, jumper cutaway spiraling main, reserve is static lined or M.A.R.D., jumper then rolls up in the reserve bridle enough to stop the reserve freebag from leaving the container, as jumper is rolled back out of the bridle the reserve canopy deploys and saves their life. Is this possible? Pro? Con?

If you're in a spin, centripetal force is going to throw you away from the main. If the reserve bridle is attached via Skyhook or DRX, *how* is the jumper going to get "rolled up" in the reserve bridle? I don't see how there's any time for it to happen. The documented experience of test jumps/customer cutaways seems to point to line twists being the worst malfunction experienced to date. Your scenario seems more likely in the slower, "normal" reserve deployment.

If memory serves...that was something that happened some years back in San Diego I believe.

I don't think there was a MARD involved but instead an ordinary RSL, but the incident WAS something along the lines of the jumper spinning enough to hang the res. bridel up and had to manually clear the hang up.


BKR

Oct 1, 2008, 9:44 AM
Post #29 of 107 (4108 views)
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Re: [karlm] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
Nothing but unabashed applause from here. Nice to see a manufacturer with the balls to call a schoolyard bully like Fradet out.

Expect to see him finding a reason why your rigs are banned in france without a costly, pointless refit...Unsure

C.
To clarify things, I no longer work for that manufacturer. Smile

The retrofit was designed by Eric or the safety committee and then when riggers and jumpers had it done, they ran into further red tape .... Unsure

If you need more clarification on the status of that container in France, get with the manufacturer.
The Icon is not banned and never been.Wink


riggerrob  (D 14840)

Oct 1, 2008, 10:48 AM
Post #30 of 107 (4063 views)
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Re: [skysurfcam] Skyhook Activation Stories [In reply to] Can't Post

Careful there!
Calling Eric Fradet a "schoolyard bully" borders on a PERSONAL ATTACK.

I know the difference.
As a child I was beaten up by too many "schoolyard bullies" and know that Eric Fradet is many miles from being a bully.

Eric has been ahead of the game for decades. For example, try reading his recent 600 page rigging manual.
Eric was designing, testing and TSOing MARDS long before Skyhook was introduced. Eric is also familiar with some obscure malfunction modes (e.g. the most recent fatality in the USA).
Now that he knows more about MARDs than most American manufacturers, Eric is reluctant to endorse MARDs.

As for his other Service Bulletins ... Eric is just trying to stay ahead of the game. Yes, some of his SBs seem trivial, because you have to make three other mistakes before they will prevent a malfunction. Good packers don't need all of Eric's SBs, but bad packers desperately need his SBs.
For example, the SB requiring relocation of AAD cutters in Icons ... you only need the SB if you are a clumsy reserve packer who installs a closing loop a mile too long ... trust me ... there are plenty of idiots out there trying to re-invent the closing loop and Eric is just trying to keep the idiots alive.

Ignore Eric Fradet's advice at your peril!


karlm

Oct 1, 2008, 10:52 AM
Post #31 of 107 (4066 views)
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Re: [BKR] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
The Icon is not banned and never been.Wink

It was however grounded due to the AAD cutter placement, and all Icon had to be retro fitted with the modification stipulated by FFP (Fédération Française de Parachutisme) ... they went so far as to require all visiting jumpers who had the Icon to have the modification, not sure if that still is in place.


BKR

Oct 1, 2008, 11:11 AM
Post #32 of 107 (4043 views)
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Re: [karlm] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
In reply to:
The Icon is not banned and never been.Wink

It was however grounded due to the AAD cutter placement, and all Icon had to be retro fitted with the modification stipulated by FFP (Fédération Française de Parachutisme) ... they went so far as to require all visiting jumpers who had the Icon to have the modification, not sure if that still is in place.


And why??? Because the container could stay closed when the aad fired if installed as it was... This is not a banned, this prevent people to be killed because of a "possible" malfunction. Icon was not the only rig to have to switch the aad installation from one point to another. Even Airtec has sent an info about this.
This switch has shown other problems but it works better. Many container because of a closing loop lenght a bit longer (after packing) have this problem. Even if the rigger pack correctly with the right loop lenght this can occured later.
So, the Icon never been banned.. It has been treated like other rigs been.


mnealtx  (B 30496)

Oct 2, 2008, 1:22 AM
Post #33 of 107 (3943 views)
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Re: [airtwardo] Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories) [In reply to] Can't Post

In reply to:
If memory serves...that was something that happened some years back in San Diego I believe.

I don't think there was a MARD involved but instead an ordinary RSL, but the incident WAS something along the lines of the jumper spinning enough to hang the res. bridel up and had to manually clear the hang up.

Thanks, Jim - as I said above, it seems more likely (to me, anyway) to happen in a 'normal' reserve deployment than with SH/DRX.


jurgencamps  (D License)

Oct 2, 2008, 3:56 AM
Post #34 of 107 (3914 views)
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Re: [jumpwally] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
Can you explain further your fun+correst size container combo's..? I have nop idea what you mean...

Small main, big reserve.


billbooth  (D 3546)

Oct 2, 2008, 8:42 AM
Post #35 of 107 (3832 views)
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Re: [phoenixlpr] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
What a hack is M.A.R.D.? Which manufacturer is providing it as an options? Where can I read the relevant marketing mabo-jumbo?
I devised the term M.A.R.D. (Main Assisted Reserve Deployment) several years ago at a TSO committee meeting, as a generic term for all Skyhook-like Devices. We needed something to write into the regs. I tried to come up with a better sounding acronym, but alas, within the time allotted, the poet within me failed.

I worked on MARD devices from the early 80's until the early 2,000's, when the Skyhook was finally ready. In that time I went through many designs. Three were good enough to actually drop test, but all had "fatal flaws" until the Skyhook. It passes even my most dastardly scenarios.

I developed the Skyhook because MARD systems meet very real needs:
1. Four tandem pairs have tumbled through reserve lines after a breakaway resulting in fatalities. This has also happened to at least two solo jumpers that I know of.
2. Many jumpers have gone in after low breakaways, with one or two lines stows left. I've watched two myself.
3. Many jumpers have had wraps too low to cutaway without a MARD system. I watched one of these also. (Recently, in Texas, two jumpers, in a low wrap, cutaway. The one with the Skyhook made it, the other didn't.)
4. The Collins' Lanyard (a part of the Skyhook system) has saved several lives when the RSL side riser released prematurely because of mis-rigging or hard opening. In this scenerio, you're under your reserve before you even know what happened.

Reserve deployments are simply cleaner and faster with a MARD system, and line twists are far less likely to happen. At first, I worried about some of the points brought up in this string, but after 6 years, millions of jumps, and thousands of cutaways on over 6,000 Skyhook equipped rigs, I think the device has proven both its safety and usefullness.


phoenixlpr  (D 3049)

Oct 2, 2008, 9:35 AM
Post #36 of 107 (3822 views)
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Re: [billbooth] Skyhook Activation Stories [In reply to] Can't Post

Thanks! I've a read a lot about Skyhook.


eric.fradet

Oct 2, 2008, 10:18 AM
Post #37 of 107 (3797 views)
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Re: [billbooth] Skyhook Activation Stories [In reply to] Can't Post

How many test have been done in this situation :
Reserve container opens during the main opening shock ?
I can tell : none, test jumpers are the regular skydivers as usual !
and it is not a rare situation ! this scenario can and will be repeated..
in this case : the reserve pilot chute do not disconnect right away from the Skyhook because the break cord holds too much, the system would require much more airspeed for the reserve pilot chute to release the red riggers thread tack(where the RSL loops around the Skyhook) from the red lanyard.Then in fact in this situation,once the reserve bag falls down from the reserve pack tray before the Reserve PC disconnect the Skyhook =>it is over, you just can expect the reserve lines be captured by the reserve bridle.

because the reserve bag floats behind the jumper, it will load on the Skyhook which stay captured on the kicker flap, still connected to the red lanyard, not leaving any chance for the break cord to release, since the tension comes from the wrong direction = reserve bag which loads more than the reserve PC because it is heavier than the reserve pilotchute.
I am sorry the Skyhook does not work in this situation, it is as simple as that.
I am keeping on to say this device is the most NON useful found in the skydiving sport, which is OK as long it is not unsafe..


eric.fradet

Oct 2, 2008, 10:40 AM
Post #38 of 107 (3777 views)
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Re: [karlm] Skyhook Activation Stories [In reply to] Can't Post

Eric

Correct me if I'm wrong here, but you are saying that you are not in favor of a "MARD" system in sports skydiving? So be it the SkyHook or the DRX from Mirage.

If so I am calling you out on this, as it was not a few months ago when you e-mailed me asking for Aerodyne to consider your design instead of the UPT SkyHook or DRX systems currently available (not sure if the DRX is yet in production)

You also went on in the literature as to why your system was better than the current systems available etc etc

Do I sense a level of professional jealousy?

To answer your question :no jealousy, I have 2 hats : one as a designer is dedicated to develop the best device as possible, the other one : my job is to protect users in France, as long I can develop the best Non useful MARD device I will certainly doing it, on the other hand, to do my job right : I will be the first one to ground any MARD including and starting with my own device as long I have a doubt.
actually all manufacturers want to offer a MARD, not because they like the device (it just makes it more complicated to build the rig), but because all the regular skydivers have been asking for it without knowing why and how it works, but because someone has been convincing them they cannot live without it...


erdnarob  (D 364)

Oct 2, 2008, 11:11 AM
Post #39 of 107 (3755 views)
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Re: [BKR] Skyhook Activation Stories [In reply to] Can't Post

It is always amazing to see that people jumped to conclusion based on a single event or case. I have also to point out the general reluctance of well established persons for something new. Example: In the 70s I was in Montreal at the CSPA Annual General meeting and has been flabbergasted by the demo of the brand new and never seen 3 ring release. It was just two #7 webbings connected by the 3 ring release and locked by a drinking straw. A guy and myself were pulling at both ends and when the straw was pulled away came the release, smooth and easy. That was for me LOVE AT FIRST SIGHT and I knew right away that this 3 rings release was what we needed. It was sad to hear my rigger course director made fun of the 3 rings as "another gimmick". People however tried suddenly to invent their own release system but the 3 ring release became the standard of the world. Even the Russian and Bulgarian made rigs have the 3 rings. In April 1978 I got and started jumping my first WONDERHOG including the 3 ring release. [people who ignore history are condemned to repeat its mistakes]
I personnaly followed the evolution of the Skyhook and it was at the last Reno PIA symposium that I was really convinced that we had in the Skyhook something really improving the safety after seeing the demo and the seminar from Bill Booth. Since March 2008 I have my Vector 3 including Skyhook and magnet risers covers.
Some people might be good technicians but not able to spot what is a good invention. My background: I am a mechanical engineering technician, has worked as a draftman designer for mechanical devices, I worked for Bombardier as a quality control technician, I am also a physics-mathematics specialized teacher, a pilot, a rigger and a jumper but before all I am a very curious person trying to keep his mind open. That background helps me to see what is a good design or not as long as mechanics is involved.
Jumping to conclusion based on a single event is not scientifically acceptable. The occidental modern world is there because science and mathematics were permitted to evolve. It has been a resistance or even direct attack against them due to believers of all kind or statu quo afficionados . The Skyhook will not solve all skydiving problems but its use by thousand jumpers shows us it is a good design. I even have a skyhook demo which I have shown several times at different DZs I have visited this year and people can see in front of their eyes how it really works. Better yet, in late August I had a total mal when my jumpsuit zipper gave up in freefall. I couldn't locate my hackey after trying twice then I pulled my reserve handle. My reserve was pulled by the pilot chute and needed to have the Skyhook disconnects which it did smoothly.


NickDG  (D 8904)

Oct 2, 2008, 12:06 PM
Post #40 of 107 (3721 views)
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Re: [eric.fradet] Skyhook Activation Stories [In reply to] Can't Post

I'm going to try and not make this sound too sappy, but I'll probably fail . . .

I've followed the careers of both Eric Fradet and Bill Booth for a very long time. And I can say without hesitation thank God for both of them . . .

Between the two you are getting all the perspective and information you need to make an intelligent decision.

Eric I initially knew from the BASE side of the house and his depth of knowledge and judgment has continually amazed me.

And Bill is the only skydiving manufacturer I don't employ the "Two Year Rule" on while with some manufacturers I stretch it to three years. I trust Bill Booth right out of the box. And where it says "Master" on his rigger's ticket it really should say Wizard.

However, that being said, in a overall sense young skydivers do need to follow Eric's advice and be a bit more skeptical. Skepticism is a life saver in this sport. I'm become (just lately) pro-Skyhook but I can agree with Eric in wishing we didn't need some of these things in the first place. I wish skydivers as a group were just flat out better at saving themselves in bad situations.

But wishing ain't gonna get it done. And there is no doubt, for whatever reasons, we do need some of these things to avoid needless deaths.

Today's jumper has a myriad of gear choices, way more than we had in the beginning of our jumping careers. We had Sherman's Racer and Booth's Wonderhog with every other container being mostly knock-offs of those two. Canopies were all pretty generic except for their names and offered in just two sizes - large and extra large. I can even recall earlier times when a custom container meant your ripcords faced inboard instead of outboard. Simpler times indeed.

So if you're seeking advice on a Skyhook, or anything else, listen only to those who lay it out and let you decide. But, if the first thing you hear is "You gotta have this!" Turn around and run for your life. That's not deciding, that's just following . . .

NickD Smile


billbooth  (D 3546)

Oct 2, 2008, 12:21 PM
Post #41 of 107 (3718 views)
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Re: [eric.fradet] Skyhook Activation Stories [In reply to] Can't Post

Yes Eric, but for this to cause a real problem, the reserve container must open at precisely the wrong moment during the main opening sequence: ie below about 25 miles an hour, but before opening shock. (If it opens above 25 mph, the reserve pilot chute will release the Skyhook and start to deploy the reserve normally. If the reserve container opens after opening shock, the reserve bag will stay in the container. The Skyhook, in this case, may help prevent a dangerous two-out situation.)

Then (of course) you must have a malfunction of your main which requires a cutaway. Even then, the reserve is not necessarily "locked-up", and may function normally if you cutaway.

All two-out situations, where the reserve bag falls out of the container during opening shock (Skyhook or not) are dangerous, because they carry the risk of the bag flipping through the reserve lines and causing a bag-lock. But, as I said above, if you don't have to cutaway from you main, this does not cause a major problem.

Saying that this is problem that should stop anyone from using a Skyhook is exactly like saying no one should use AADs because they might fire during during main opening sequence, causing a main-reserve entanglement. These two scenarios are directly related, because the main way the above Skyhook scenario could happen is if you pull too low, and the AAD goes off at just the wrong moment. The main lesson here is to respect your AAD, and not pull too low.

The benefits of the Skyhook far outweigh this risk.


KellyF  (D 13826)

Oct 2, 2008, 2:30 PM
Post #42 of 107 (3667 views)
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Re: [billbooth] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
Yes Eric, but for this to cause a real problem, the reserve container must open at precisely the wrong moment during the main opening sequence: ie below about 25 miles an hour, but before opening shock. (If it opens above 25 mph, the reserve pilot chute will release the Skyhook and start to deploy the reserve normally. If the reserve container opens after opening shock, the reserve bag will stay in the container. The Skyhook, in this case, may help prevent a dangerous two-out situation.)
Until the jumper, unaware that their AAD fired, releases their brakes and/or turns, THEN initiates the deployment of their reserve at a lower altitude.

In reply to:
Then (of course) you must have a malfunction of your main which requires a cutaway. Even then, the reserve is not necessarily "locked-up", and may function normally if you cutaway.

All two-out situations, where the reserve bag falls out of the container during opening shock (Skyhook or not) are dangerous, because they carry the risk of the bag flipping through the reserve lines and causing a bag-lock. But, as I said above, if you don't have to cutaway from you main, this does not cause a major problem.
I agree that it is not necessary to cut your main away in this type of situation, but it IS necessary for the jumper to assess the situation and know what the best course of action is going to be- "should I cutaway? Will my reserve come out of the bag if the pilot chute continues deployment?" Not really a situation I would like to be in at ~750 feet).

I disagree on the notion of the reserve bag flipping through the lines too. I just don't see it happening when the lines are creating drag on one side of the bag as it's falling- it's like saying a tandem pair can get wrapped up in their drogue after it's deployed. It's even more unlikely to happen if there is a pilot chute pullling on the other end of the bag. However, if the pilot chute or any part of the bridle are coming from the same spot on the jumper as the lines, a bag/line entanglement is much more likely if the bag turns as it is falling or if it stops before it releases the safety stow.

In reply to:
Saying that this is problem that should stop anyone from using a Skyhook is exactly like saying no one should use AADs because they might fire during during main opening sequence, causing a main-reserve entanglement. These two scenarios are directly related, because the main way the above Skyhook scenario could happen is if you pull too low, and the AAD goes off at just the wrong moment. The main lesson here is to respect your AAD, and not pull too low.
I agree that you should respect your AAD, but I also know several people that have had theirs fire during main deployment (one person had it happen twice in 24 hours). I also agree with Eric that it comes down to "what is the more likely 'malfunction'?". In your canopy collision example above, the jumper with the skyhook also cutaway at an altitude high enough for a standard RSL to work (although I'm sure he/she will never jump without a skyhook againSmile).

Regardless of our opinions on the issue, it will be a non-issue in the futureSmile


SimonBones  (D 28573)

Oct 2, 2008, 4:33 PM
Post #43 of 107 (3636 views)
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Re: [billbooth] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
Then (of course) you must have a malfunction of your main which requires a cutaway. Even then, the reserve is not necessarily "locked-up", and may function normally if you cutaway.

All two-out situations, where the reserve bag falls out of the container during opening shock (Skyhook or not) are dangerous, because they carry the risk of the bag flipping through the reserve lines and causing a bag-lock. But, as I said above, if you don't have to cutaway from you main, this does not cause a major problem.

Mr. Booth, I have a question with this scenario regarding rigs equipped with the Collins lanyard. If the RSL was loose wouldn't the weight of the freebag load the Collins lanyard, thus pulling left side CA easily enough to release left main riser? If that situation did occur, the jumper would be pretty much left without an option to cutaway and hope the reserve works right? You know your gear much better than I do.

-Simon


CrazyL  (D 17699)

Oct 2, 2008, 6:18 PM
Post #44 of 107 (3610 views)
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Re: [mnealtx] Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories) [In reply to] Can't Post

In reply to:
In reply to:
I'm surely interested in Pro's and Con's of the M.A.R.D. but only know about 'here say' no real proof. So help me out here, here's a scenario that i 'heard' about, jumper cutaway spiraling main, reserve is static lined or M.A.R.D., jumper then rolls up in the reserve bridle enough to stop the reserve freebag from leaving the container, as jumper is rolled back out of the bridle the reserve canopy deploys and saves their life. Is this possible? Pro? Con?

If you're in a spin, centripetal force is going to throw you away from the main. If the reserve bridle is attached via Skyhook or DRX, *how* is the jumper going to get "rolled up" in the reserve bridle? I don't see how there's any time for it to happen. The documented experience of test jumps/customer cutaways seems to point to line twists being the worst malfunction experienced to date. Your scenario seems more likely in the slower, "normal" reserve deployment.
Not my scenario per se. I just posted someone elses scenario. Eric has been around a long time as many others have. Maybe the scenario is valid, I don't know. That's why I asked sincerely. Still no hard facts to say the scenario is valid.


CrazyL  (D 17699)

Oct 2, 2008, 6:25 PM
Post #45 of 107 (3607 views)
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Re: [mnealtx] Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories) [In reply to] Can't Post

In reply to:
In reply to:
If memory serves...that was something that happened some years back in San Diego I believe.

I don't think there was a MARD involved but instead an ordinary RSL, but the incident WAS something along the lines of the jumper spinning enough to hang the res. bridel up and had to manually clear the hang up.

Thanks, Jim - as I said above, it seems more likely (to me, anyway) to happen in a 'normal' reserve deployment than with SH/DRX.
Do you know of this ever happening?


billbooth  (D 3546)

Oct 2, 2008, 6:27 PM
Post #46 of 107 (3606 views)
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Re: [SimonBones] Skyhook Activation Stories [In reply to] Can't Post

In reply to:
In reply to:
Then (of course) you must have a malfunction of your main which requires a cutaway. Even then, the reserve is not necessarily "locked-up", and may function normally if you cutaway.

All two-out situations, where the reserve bag falls out of the container during opening shock (Skyhook or not) are dangerous, because they carry the risk of the bag flipping through the reserve lines and causing a bag-lock. But, as I said above, if you don't have to cutaway from you main, this does not cause a major problem.

Mr. Booth, I have a question with this scenario regarding rigs equipped with the Collins lanyard. If the RSL was loose wouldn't the weight of the freebag load the Collins lanyard, thus pulling left side CA easily enough to release left main riser? If that situation did occur, the jumper would be pretty much left without an option to cutaway and hope the reserve works right? You know your gear much better than I do.

-Simon
For this to happen, the snap shackle would have to be released before the opening shock occurs, AND the velcro which holds down the RSL over the shoulder would have to also fail. Now you're piling improbability on top of improbability. And, of course, if both of these things did occur, the Skyhook lanyard would no longer be connected to anything anymore anyway.


eric.fradet

Oct 2, 2008, 11:57 PM
Post #47 of 107 (3553 views)
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Re: [karlm] Skyhook Activation Stories [In reply to] Can't Post

It was however grounded due to the AAD cutter placement, and all Icon had to be retro fitted with the modification stipulated by FFP (Fédération Française de Parachutisme) ... they went so far as to require all visiting jumpers who had the Icon to have the modification, not sure if that still is in place.

Actually I bench tested several Icon by test firing containers on the ground.
many of them stayed locked even with a lubricated and correct reserve loop length. It is due to the too wide reserve pilot chute cap pushing not only in the middle of the reserve cover pin flap but too hiw and too low => pitching the rongue of the reserve container flap inside the pocket where it is located.
The reserve PC cap too wide is the main issue !, when associated to the cutter location too low (on the kicker flap) it can lock up, even with the correct reserve loop length.
Which also means that moving the cutter above the reserve PC does not definetly fix this issue, even with the PIN PULLED.
For instance on Atom rig (Icon little brother) when associated with a Quick 3 (wide oval reserve PC), during re-pack cycle : when riggers pull the reserve ripcord we found one rig every 500 hundreds which stay locked up for 4-5 seconds because the reason I just wrote.
Problems could be solved with a lot of re-design or a new reserve pilot chute with small diameter.


erdnarob  (D 364)

Oct 4, 2008, 10:48 AM
Post #48 of 107 (3413 views)
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Re: [eric.fradet] Skyhook Activation Stories [In reply to] Can't Post

I have been a direct witness of such an occurrence when the AAD fired in an airplane on the ground and a friend of mine didn't get the pilot chute extraction. That rig has the AAD cutter located below the reserve bag on the reserve container floor giving the loop the maximum length. I have sent a letter to the manufacturer, to the rigger and to the chairman of the safety committe to let everybody know what was going on. The rigger said it was a bad design while the manufacturer blamed the rigger.
Earlier, I have been concerned with the problem when 3 Russian guys pulled low to find out on the ground that their rig equiped with an AAD (with cutter located below the pilot chute) hadn't been able to extract the pilot chute. That prompted the manufacturer to relocate the cutter on the top of the pilot chute.
Using my Vector III M # 348 , I and a friend of mine set up an experiment. I put a flat hook knife with a pull cord behind the wall of the reserve floor in order to cut the loop at its very maximum length. A fast camera (5 frames per second) was used to record the result. When I pulled the cord attached to the hook knife I had a perfect extraction with the pilot chute jumping vertically at 5 feet. (see the 2 pictures). I tested the Vector III pilot chute strength with a bathroom scale. Compressed at about 2 inches the strength was 40-45 pounds.
The chairman of my committe told me that seemingly all small rigs have the possibilty of such a problem (no extraction of the PC when AAD firing). The use of smaller pilot chute cap, stronger spring and relocation of the cutter is maybe the solution for small rigs.
Attachments: VECTOR RESERVE TEST4R.jpg (39.6 KB)
  VECTOR RESERVE TEST6R.jpg (44.3 KB)


mnealtx  (B 30496)

Oct 5, 2008, 1:56 AM
Post #49 of 107 (3348 views)
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Re: [CrazyL] Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories) [In reply to] Can't Post

In reply to:
In reply to:
In reply to:
If memory serves...that was something that happened some years back in San Diego I believe.

I don't think there was a MARD involved but instead an ordinary RSL, but the incident WAS something along the lines of the jumper spinning enough to hang the res. bridel up and had to manually clear the hang up.

Thanks, Jim - as I said above, it seems more likely (to me, anyway) to happen in a 'normal' reserve deployment than with SH/DRX.

Do you know of this ever happening?

Do you know of YOUR scenario with the SH / DRX ever happening? Jim just said he recalled one with a normal reserve deployment.


eric.fradet

Oct 5, 2008, 2:16 PM
Post #50 of 107 (3250 views)
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Re: [CrazyL] Pros & Cons of M.A.R.D (Was: Skyhook Activation Stories) [In reply to] Can't Post

Student Injury, ankle entanglement, - Oklahoma Skydiving Center - 27 Sept 2008 Quote | Reply

The student climbed out and was hanging on the strut as he was supposed to. When he was told to release he attempted to push himself with his hands and, instead of arching he pushed his arms and legs forward. This all resulted in him doing a back flip from the plane and then falling butt first while the main deployed. As the main came out his ankle was caught in one of the lines. The main actually fully open but was in spiraling. The student cut way and had a successful reserve deployement. He landed safely but his ankle was not broken but was very swollen. He was very lucky this was his only injury.
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I am wondering what would happen if this student had some kind of MARD ...not sure he would survive with such device


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