aad and the tragedy in zhills

[schon267 0]

I know this involves the tragedy in zhills last week with the 2 icelanders. but can someone answer my question regarding
the aads in their rigs.
I realize the aad is last ditch to save your life and altitude awarness was lost by the student in this tragedy.the mains werent deployed, but the aad fired on both mens rigs. but the news is the reserves didn't inflate in time to save these 2 skydivers. if the aad did its job and cut the reserve loose, why didn't they deploy in time like they were designed??? did the aad fire too low??? what altitude is the aad suppose to cut reserve loose? why didnt the aad/reserve system save these 2 men?

[Southern_Man 0]

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I know this involves the tragedy in zhills last week with the 2 icelanders. but can someone answer my question regarding
the aads in their rigs.
I realize the aad is last ditch to save your life and altitude awarness was lost by the student in this tragedy.the mains werent deployed, but the aad fired on both mens rigs. but the news is the reserves didn't inflate in time to save these 2 skydivers. if the aad did its job and cut the reserve loose, why didn't they deploy in time like they were designed??? did the aad fire too low??? what altitude is the aad suppose to cut reserve loose? why didnt the aad/reserve system save these 2 men?

The AAD they had was a Cypres. It fires at 750 feet at speeds greater than 78 mile per hour. The AAD fires when it senses that those parameters have been met.

At 750 feet and 120 mph you are 4 seconds from impact. The reserve is certified to open in 3 seconds or 300 feet (from container opening) so if everything works perfectly it is enough time, but the margins are very, very thin. One little thing goes wrong and there is not enough time. If speeds are faster than 120 the margins are even thinner.

There are a number of reasons that people have speculated that have caused these reserves and others in similar incidents to not open in time. Some of those reasons include too big a reserve shoved in to too small a container, pilot chute hesitations, issues with rig geometry (particularly with smaller rigs) inhibiting reserve deployment. Since the overall number of incidents is relatively small and the number of variables (rig manufacturere, rig size, reserve size, packing, etc) are large and the evidence is often ambiguous, it is very difficult to nail down the why of any incident. In the Z-hills case, we just don't know (and all the facts are not known).

The main thing I think to take is that AADs are not a magic solution that will automatically save you. There is a chance they might, but a chance they might not as well.

"What if there were no hypothetical questions?"

[NWFlyer 2]

I use an AAD Because in the case of incapacitation, it takes me from guaranteed death to possible survival. Not guaranteed survival.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[EFS4LIFE 0]

Bill Booth's Law #1- the lower your parachute is deployed, the longer it takes to open and the more likely it is to malfunction.

He makes no reference to reserve or main.

The man has been advocating for higher pull altitudes and AAD activation altitudes for awhile. Maybe we need to listen to him.

This is not the first time an AAD has fired but the reserve still does not have time to inflate. My guess is it won't be the last either.

I am an asshole, but I am honest

[popsjumper 2]

There's already a speculation thread running about this incident with lots of AAD discussion. Chop this one and go there.

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=4462807;sb=post_latest_reply;so=ASC;forum_view=forum_view_collapsed;;page=unread#unread

My reality and yours are quite different.
I think we're all Bozos on this bus.
Falcon5232, SCS8170, SCSA353, POPS9398, DS239

[RiggerLee 61]

that would be great except it was really full of fluff. I hate trying to read any thread on there. There is plenty of room for a technical, fact based, discussion. I'd be curious to hear the exact condition of the rigs at impact. Exactly where were they in the opening sequence? Did the cypresses show a record of an on time firing? Vid? But all of that will probable have to wait... for a while. But what I don't want to have to do is try to dig through all that shit for the few crumbs of relevant hard data.

In short please don't remove this or other threads like it but could we just table it till there is some kind of report?

Lee

Lee
[email protected]
www.velocitysportswear.com

[chuckakers 370]

Quote

I know this involves the tragedy in zhills last week with the 2 icelanders. but can someone answer my question regarding
the aads in their rigs.
I realize the aad is last ditch to save your life and altitude awarness was lost by the student in this tragedy.the mains werent deployed, but the aad fired on both mens rigs. but the news is the reserves didn't inflate in time to save these 2 skydivers. if the aad did its job and cut the reserve loose, why didn't they deploy in time like they were designed??? did the aad fire too low??? what altitude is the aad suppose to cut reserve loose? why didnt the aad/reserve system save these 2 men?

Before we go too far down the "we need higher AAD firing altitudes" road, let's not forget that the activation altitude itself may not have been (and IMO probably was not) the killing factor here.

In this case, the student my have been unstable, on his back, head, butt, whatever, and traveling considerably faster than at a typical belly terminal.

If that was the case, even a momentary delay in p/c launch would likely prove fatal.

And to the OP, this student my NOT have lost altitude awareness. That's only one of many reasons he may have failed to deploy for himself.

Chuck Akers
D-10855
Houston, TX

[forward 0]

If I understand correctly the primary reason for using an AAD is a last ditch attempt to save your life if you are unable to pull for yourself (being unconscious). If this is the case it seems likely that in this situation you wouldn't be in the normal belly to earth position but you'd be rather unstable and that would therefore increase the risk of your reserve not opening in time. Would this not be an argument for a slightly higher activation altitude?

As for a loss of altitude awareness aren't there other solutions such as an audible altimeter that should be your backup rather than an AAD? This obviously excludes the AFF-I instructor chasing a student scenario and in that case being somewhat altitude aware.

Please forgive any ignorance on my part due to inexperience, just trying to organize all this in my own mind...

Everything else is just noise...

[fasted3 0]

A good post. One factor you didn't mention is that when the main is still in the container, that could make it more likely for the reserve to get stuck. Probably worse if the main is a bit overstuffed.

But what do I know?

[skybytch 259]

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why didnt the aad/reserve system save these 2 men?

Wouldn't a better question be why didn't these two men save their own lives?

That little black box is NOT a guarantee of survival. There is no guarantee of survival in skydiving, regardless of how many "safety" devices you jump with.

[chuckakers 370]

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A good post. One factor you didn't mention is that when the main is still in the container, that could make it more likely for the reserve to get stuck. Probably worse if the main is a bit overstuffed.

Oh really? Where did you get that little nugget of wisdom?

Chuck Akers
D-10855
Houston, TX

[Divalent 89]

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why didnt the aad/reserve system save these 2 men?

Wouldn't a better question be why didn't these two men save their own lives?

No, that's a separate question. Many many skydivers want to the know the answer to the first question, and it makes no difference why, in this instance, the two ended up that low to begin with.

[Skydivesg 6]

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If I understand correctly the primary reason for using an AAD is a last ditch attempt to save your life if you are unable to pull for yourself (being unconscious). If this is the case it seems likely that in this situation you wouldn't be in the normal belly to earth position but you'd be rather unstable and that would therefore increase the risk of your reserve not opening in time. Would this not be an argument for a slightly higher activation altitude?

As for a loss of altitude awareness aren't there other solutions such as an audible altimeter that should be your backup rather than an AAD? This obviously excludes the AFF-I instructor chasing a student scenario and in that case being somewhat altitude aware.

Please forgive any ignorance on my part due to inexperience, just trying to organize all this in my own mind...

You are correct in most of your thoughts. Many people do not want students to be wearing audibles because they want them to learn to use their eyes and visual altimeter to learn altitude awareness rather learn to depend on an electronic audilbe device. However I think it would be hard to argue against an audible set for 2,000 ft, 1,500 ft and 1,000 ft. At that point it's more about life saving awareness than altiude awareness.

I just posted this on the other thread regarding higher AAD firing alitiudes: More and more people agree with this. The AADs today can be set for what ever hard deck the user/owner wants. I do know of some schools who set them 300 feet higher.

It may or many not have helped these two people but unless you're John Sherman, it's becomig more and more difficult to come up with a sensible argument against the increased firing altitude. My guess is: after this incident more people will give greater consideration to doing the same thing.

Be the canopy pilot you want that other guy to be. .

Be the canopy pilot you want that other guy to be.

[schon267 0]

thanks for the replies! I trained at zhills, my instructor on aff jumps told me right away that pulling is job 1 and he wasnt chasing me below his hard deck. I dont blame him either. its my responsability to pull at correct altitude. we all know that being skydivers. I thought aads pulled reserves higher then 750'. I seem to have thought it was 1,200'? obviously maybe the fear of having 2 out made that number go lower. just wnt to learn from any tragedy, sorry to the families and friends of these 2 jumpers. hopefuly we can find out details an learn from this accident. blue skies everyone

[fasted3 0]

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A good post. One factor you didn't mention is that when the main is still in the container, that could make it more likely for the reserve to get stuck. Probably worse if the main is a bit overstuffed.

Oh really? Where did you get that little nugget of wisdom?

I don't remember well enough to reference it for you, sorry. Do you think it's not true? It does seem to make sense to me, but I'm happy to get corrected if I'm wrong.

But what do I know?

[faulknerwn 36]

Has it ever been considered taking the rigs on any of the multiple events now where the aad didn't get a canopy open in time - and doing a dummy drop like the TSO tests are - and see what happens? Preferably with the same length closing loop and such?

Even if the rig was cut off following an accident you could duck tape it to a drop test dummy. It seems like that could be enlightening to see what it was about the particular rig/canopy situations that caused the canopy to not deploy in time..

And any of the folks who've been around a while help me out - I really only recall hearing about all of these aads not getting a reserve out in time incidents for the last 5 years or so. I just don't recall anything like that back in the 90s. I certainly recall reading about numerous AAD saves, but I don't recall about hearing where the reserves weren't opening in time. It might just be my old age not remembering - anyone else have a recollection on this? I do know rigs have gotten dramatically smaller and tighter in that time - and I have definitely seen such tightly packed rigs I would be afraid to jump.

[theonlyski 3]

While this could be useful, it's hard to recreate the exact events. It might rule out the possibility of the container being over stuffed, but really, a lot of it would depend on how THAT rigger packed it. I bet you could put 10 riggers in one room with one rig, ask them to pack it a few times each and you'll get about 15 different ways of distributing the bulk of the packjob.

My curiosity would like to see another one of the riggers packjobs (provided they were packed by the same rigger). But there is no reason to believe that it was caused by any one thing rather than the unfortunate chain that gets so many people in trouble.

"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
I'm an asshole, and I approve this message

[JohnSherman 1]

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Has it ever been considered taking the rigs on any of the multiple events now where the aad didn't get a canopy open in time - and doing a dummy drop like the TSO tests are - and see what happens?

You bet, I have been encouraging investigators to do a test. You really don't need a dummy, just tape the rig up and throw it out.

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And any of the folks who've been around a while help me out - I really only recall hearing about all of these aads not getting a reserve out in time incidents for the last 5 years or so. I just don't recall anything like that back in the 90s.

This has been going on for about 20 years. Before AAD's they were reported as "low pull" on the reserve. As AAD's came into service we started seeing events as we do today. It was slow at first as the installed base grew. We will see even more as we go along if we don't fix it.

[df8m1 19]

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Has it ever been considered taking the rigs on any of the multiple events now where the aad didn't get a canopy open in time - and doing a dummy drop like the TSO tests are - and see what happens?

You bet, I have been encouraging investigators to do a test. You really don't need a dummy, just tape the rig up and throw it out.

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And any of the folks who've been around a while help me out - I really only recall hearing about all of these aads not getting a reserve out in time incidents for the last 5 years or so. I just don't recall anything like that back in the 90s.

This has been going on for about 20 years. Before AAD's they were reported as "low pull" on the reserve. As AAD's came into service we started seeing events as we do today. It was slow at first as the installed base grew. We will see even more as we go along if we don't fix it.

There should be a data base created that has;
1) the type of container and it's pack volume,
2) the pack volume of the canopies,
3) the reserve pilot chute that was used,
4) the configuration at the time of the reserve ripcord being pulled or AAD firing,
(main deployed or not)
5) was the reserve handle pulled or was an AAD the primary method to open the
reserve
6) What AAD was installed if any.

I would think that after 10+ instances, there should be enough data to start to identify what they all had in common, and if the individual commonalities could have contributed to the reserve not inflating in time to slow the jumper to a survivable speed.

If for example they all had an AAD fire, and they all had the same AAD, then that would be a starting point for an investigation to determine if the AAD fired low, or there was a compatibility issue with the configuration of the AAD and container.

Or, if they all had the same reserve pilot chute, that would direct attention to the amount of drag it is capable of producing in the burble of a jumper, and is it sufficient to extract a reserve free bag from a container.

This is a very troubling situation, as how can the skydiving community encourage the use of AADs if they can not get a reserve over head in time when they are working properly? I mean, you can’t say anyone who doesn’t have an AAD is less safe, if an AAD can’t get a reserve out in time anyway.

[schon267 0]

so mr. moderator and other very experienced jumpers, I seem to remember when i went through aff that the aad was suppose to fire at 1,200'. Im old and may be mistaken, I do know it started higher and because of the 2 out scenario they lowered altitude that the aad's fired. but 750" seems way to stinking low to me, like another said , thats 4 seconds away from being a pancake. I know I'm out of the mainstream loop, cuz I don't jump as much as I would like too, somebody said this was, or still is a big topic of conversation or has big differences of opinions. thanks again for you guys insight. just trying to learn.

[Southern_Man 0]

Here is the USPA advisory about the situation, issued three years ago yesterday. Just adding for more information and context:

http://www.uspa.org/Portals/0/Downloads/Skydiver%20Advisory3-31-2010.pdf

"What if there were no hypothetical questions?"

[wmw999 2,122]

When the Cypres first came out, the vast majority of skydivers were doing relative work, which meant slower belly speeds, and generally a belly-to-earth orientation when the reserve is deployed.

However, for a reserve to open in 3 seconds, if you're going at 120 mph (flat and stable), you go about 175 feet for each second, for a (optimally) max distance of about 525 feet. That's a very short reserve ride.

Now let's say that instead of flat and stable, you're that AFF instructor chasing a flailing or limp student (FF speed closer to 170 mph). Now you're going nearly 250 feet per second, and that optimally max opening of time puts you opening right around impact.

3 seconds is supposed to be the max. It's supposed to take less time. But supposed is a very big word in skydiving. It's much better to take care of things yourself, and be open before then.

That's why the Cypres is a last-ditch chance. Because things still have to go right. And if all the talk running around about tight reserve/container combinations are true, then that optimal 3-second time might not always be accurate. I do know my reserve isn't tight in the container. I don't know about the differences between student and experienced Cypres. I do know that it's my job to make sure I have a canopy deployed before I bounce.


I have a friend who cut away from a canopy wrap, knowing that the other person was now going to die. It was devastating for them, and took a long time to get over. I can imagine that giving up on chasing a student would be utterly devastating for an instructor. I still think it takes less time to get over being devastated, than being dead.

Wendy P.

There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

[df8m1 19]

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When the Cypres first came out, the vast majority of skydivers were doing relative work, which meant slower belly speeds, and generally a belly-to-earth orientation when the reserve is deployed.

However, for a reserve to open in 3 seconds, if you're going at 120 mph (flat and stable), you go about 175 feet for each second, for a (optimally) max distance of about 525 feet. That's a very short reserve ride.

Now let's say that instead of flat and stable, you're that AFF instructor chasing a flailing or limp student (FF speed closer to 170 mph). Now you're going nearly 250 feet per second, and that optimally max opening of time puts you opening right around impact.

3 seconds is supposed to be the max. It's supposed to take less time. But supposed is a very big word in skydiving. It's much better to take care of things yourself, and be open before then.

Wendy P.

The equation is; fall rate X max reserve deployment time = a Min activation altitude. It is simple math and hard to argue with IMOP.

Also IMOP, no one should still be in free fall bellow 1500ft. Every electronic AAD has the capability of being intelligent, but a computer is only as intelligent as the programmer allows it to be. The military AADs that I am currently working on are intelligent, and capable of identifying the situation in it is in, and making adjustments accordingly to maximize the possibility of a successful out come. It is not hard to make an electronic AAD able to adjust its activation altitude according to the free fall speed at the time the jumper reaches the altitude threshold.

There is no reason to push the error margin to the bottom of the scale, that is where the planet is, it makes more sense to shove the error to the upper end and leave a cushion on the bottom. Personally, I would like more than 1.5 seconds to set up my landing.

Just a thought, which is worse, being a dumb ass & pulling low, and get two out with altitude left to deal with it, or being a dumb ass and not having enough time for the reserve to deploy? I bet at some point as the planet comes rushing up, one would be wishing they had two out.

[df8m1 19]

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Here is the USPA advisory about the situation, issued three years ago yesterday. Just adding for more information and context:

http://www.uspa.org/Portals/0/Downloads/Skydiver%20Advisory3-31-2010.pdf

Some where there should be a collection of incident reports for all the instances where the reserve failed to deploy in time after an AAD fired. These reports should indicate the container and reserve combination, and which AAD it had.

I would only focus on rigs with an AAD because that will provide as known of a pack opening altitude as possible, as who knows when a jumper with out an AAD pulled the reserve rip cord.

If all the rigs had the same AAD in them, then the “actual” activation altitude would need to be looked at, not the altitude that “the AAD thought it was at”. Now the AAD manufacturers will point to the containers, and that would be supported if there were different AADs used…SO…

If the rigs had different AADs in them, then not only do we need to verify that the AADs are firing at the proper AGL altitude, but additionally, were the reserve “systems” of those rigs capable of operating according to the TSO that they were issued under.

[Southern_Man 0]

I believe the PIA technical committee has all of those details but I don't know if they are available to the public.

"What if there were no hypothetical questions?"