Just An Idea

[btwitche1975 0]

I am a just a newbie but I thought of a possibly valuable feature which could be incorporated into an AAD without much additional cost..

Considering many of the reports of two out scenarios caused by an AAD firing while the main is sniveling or when the jumper deploys too low, I reasond that the AAD should be aware of these situations.

With a simple sensor to detect a main's bridal being extracted or possibly the D-bag being withdrawn (probably better) the AAD could be aware that an attempt is being made to deploy a parachute. If the AAD was a little smarter it could allow for an additional three/four seconds for things to become corrected before firing. I believe it's true that if your main's PC or D-bag is out already, your main has a latency advantage over your reserve which will surely deploy (buy maybe not inflate) at a later time if it does at all.

If the AAD were to give a three or four second (or possibly some alltitude unit) extension to its programmed deadlines the instant the deployment is detected, I think it could save more people than it could hurt.

The system would use a simple conduction loop to indicate the instant of deployment and if that were to malfunction in any way the system would just act like a run-of-the mill AAD as it would never detect the deployment condition and hence insert no delay.


Maybe this is an old idea and I am beating a dead horse. Maybe it is idiotic.

Let me know, and don't hesitate to criticize with a good point.

Thanks

/*
This is my rig... There are many like it, but this one is mine.
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[bob.dino 0]

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If the AAD were to give a three or four second (or possibly some alltitude unit) extension to its programmed deadlines...

Most AADs are programmed to fire at 750ft. If you've got a pilot-chute in tow or a baglock and the AAD detects this and waits a significant period of time, you're likely to die.

[Cloudi 0]

I'm not smart enough to comment on the logistics of what you're suggesting, but it seems to me that if the AAD is firing, it's doing its job and putting a canopy out there when someone has "scared" it with a low pull or doesn't have anything out at all.

IMO, if you don't want two out, you have options before it ever gets to that point. The AAD is a last resort life saving tool. It isn't meant to do your thinking for you.

If you want to prevent your AAD from firing, you simply have to pull well above its firing altitude. The longer your canopy likes to snivel, the higher above that altitude you should pull.

Not knocking your suggestions. I'm sure AAD's will eventually evolve in the direction you have suggested, just not sure if it's a good idea.

Kim
Watch as I attempt, with no slight of hand, to apply logic and reason.

[btwitche1975 0]

Agreed. A form of this may not be suitable for the expert Cypres.
At higher altitudes I think it may be another story.

If a deployment initiation was JUST detected it seems to me that the chances of the main deploying correctly alone are better than the main and reserve deploying together/simultaneously.

Given that a not known to be malfunctioning main that was JUST deployed is better than a guaranteed two out or possible entanglement, it may help.

/*
This is my rig... There are many like it, but this one is mine.
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[Hawkins121 0]

would you need a cypress at higher altitudes?

[btwitche1975 0]

The tandem versions activate at 1900 feet.

/*
This is my rig... There are many like it, but this one is mine.
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[MB38 0]

If I pass 750 feet with my main bridle just reaching extension - knowing the way that my canopy often snivels - I will probably die. I'm not saying that it always takes 750 feet from pitch to flight - it's probably only happened once or twice - but it will certainly happen again on that one particular occasion. I would much rather have a two-out - particularly at my [fairly low] wingloading - than snivel into the ground.

Drama aside, I think that the added complexity and potential for failure [be it mechanical or packer-induced] would do more harm than good. Two-outs happen; most of the time they are nothing more than frustrating.

I can only think of one death from an AAD-induced two-out and it was an extreme case [a case that Airtec has released a new version of the Cypres to hopefully prevent from ever occurring again].

Obviously that was a canopy speed issue and not a deployment issue, but the result is the same.

With regards to other two-outs... have there been any fatalities? Most notably of the low-pull variety? I'm not trying to use this as a point against the AAD design... I'm just curious.

Anyway, I think your heart is in the right place but such a design would just add too much complexity for not enough gain in my opinion.

I really don't know what I'm talking about.

[btwitche1975 0]

Heres my thinking

180 ft/sec

Scenerio 1:
*Diver pulls at 1200
*Dbag out at 1000 (this is where we shedule 2 sec)
*snivelling at 750

What is best now; fire or wait a second more?
With a two second delay after dbag removal this changes the cypres fire to at least 640 ft (assuming we dont speed up: most likely we will be going slower)

Scenario 2:
*Diver pulls at 1000
*Dbag out at 800 (schedule 1.5 second delay)
*750 comes what is best here?? fire reseve or not

With a 1.5 second delay we may have the main open before 700; if not we deply reserve at ~650 ish

Senario 3:
*Diver pulls at 800 (good luck)
*AAD wil not get fancy with this one, it will fire @ 750 regardless.


The equations are much more favorable/managable for the tandem version.


The rigging requirement would involve looping a tiny wire around a small loop in the Dbag when it is placed in the container. If this is done incorrectly then the AAD works as it did without this crazy idea

PS, Im not trying to argue with anyone. I know I am less experienced and probably in the wrong here. I just like technical debate.

/*
This is my rig... There are many like it, but this one is mine.
*/

[kelpdiver 2]

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What is best now; fire or wait a second more?
With a two second delay after dbag removal this changes the cypres fire to at least 640 ft (assuming we dont speed up: most likely we will be going slower)

every assumption like that furthers your KISS vioation. In a bag lock, you will start to speed up at some point - maybe not within 2s, but soon after.

These sort of mods have been hashed out before - you might wanto check it out. But in short, jumpers need an AAD with predictable behavior. You can't have to think about what it might do based on a highly unreliable deployment detection device. Instead you know that if you throw out well below the BSR min, it is likely to fire. If that's a likely result, don't use one.

[dontiego 0]

And what about the AAD releasing your main half a second before opening your reserve?
Maybe not practical to have two cutters to your three-rings loops, but...
Why not?

"We call on the common man to rise up in revolt against this evil of typographical ignorance."
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[kallend 1,620]

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And what about the AAD releasing your main half a second before opening your reserve?
Maybe not practical to have two cutters to your three-rings loops, but...
Why not?

I kind of like mine just the way it is.

...

The only sure way to survive a canopy collision is not to have one.

[ChrisL 2]

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. If the AAD was a little smarter it could allow for an additional three/four seconds for things to become corrected before firing.

3 or 4 seconds of freefall at cypres fire altitude pretty much puts you in the dirt.

__

My mighty steed

[GreenMachine 0]

Like the other guys have already said....it is cool that you are thinking, keep it up and you might invent some great stuff like Bill Booth and some of the other greats have, but this particular idea is not good. FYI --- I am pretty sure the Cypres brand AAD comes in 3 varieties: Tandem, Student, and Expert, each with its own corresponding logical firing altitude.

As someone above already said, your AAD should be a last ditch, emergency insurance policy that you hope you never, ever use, kind of similar to the RSL in that students are taught to pull their own reserve handle after a cutaway instead of depending on the lanyard to do it for you.

The absolute best ways to prevent any of the problems you are trying to address are known and straight forward:
1) Plan an appropriate break off altitude
2) plan an appropriate deployment altitude
3) maintain altitude awareness
4) dive your plan

By the way, an audible altimeter would be more helpful than adding complexity to the rigging and packing of our parachutes. Furthermore, if you lose altitude awareness you should know how to respond. If you wake up to the fact that you are in freefall at 1,000 feet go straight to your reserve, because this is an emergency, it is more reliable, and it prevents the dreaded/inconvenient 2 parachutes out scenario.

Rigger, Skydiver, BASE Jumper, Retired TM

[kallend 1,620]

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Furthermore, if you lose altitude awareness you should know how to respond. If you wake up to the fact that you are in freefall at 1,000 feet go straight to your reserve, because this is an emergency, it is more reliable, and it prevents the dreaded/inconvenient 2 parachutes out scenario.

There seems to be a consensus that while people INTEND to do this, muscle memory takes their hand to their main anyway.

I know (knew) two people knocked unconscious in freefall. One was saved by his CYPRES, the other had his CYPRES turned off, and died.

...

The only sure way to survive a canopy collision is not to have one.

[GreenMachine 0]

The "Wake Up" comment was not meant to imply they were really asleep (or unconscious) but more like they weren't paying attention.

And yes, I agree with you, muscle memory/habit to go for the main first is very strong. I once had a guy pull right under me, the near collision freaked me out for a good couple of seconds, when I looked down and realized I was real low I should have pulled the reserve for sure but dumped the main -- no wave off of course

Rigger, Skydiver, BASE Jumper, Retired TM

[catfishhunter 1]

Quote

Heres my thinking

180 ft/sec

Scenerio 1:
*Diver pulls at 1200
*Dbag out at 1000 (this is where we shedule 2 sec)
*snivelling at 750

What is best now; fire or wait a second more?
With a two second delay after dbag removal this changes the cypres fire to at least 640 ft (assuming we dont speed up: most likely we will be going slower)

Scenario 2:
*Diver pulls at 1000
*Dbag out at 800 (schedule 1.5 second delay)
*750 comes what is best here?? fire reseve or not

With a 1.5 second delay we may have the main open before 700; if not we deply reserve at ~650 ish

Senario 3:
*Diver pulls at 800 (good luck)
*AAD wil not get fancy with this one, it will fire @ 750 regardless.

Each of those scenario's
1) Should not have Happened
2) If you find they did happen you should go to your Reserve
3) You want your reserve to fire because if you have a main like mine that can take over 800' to open and just might decide to snivel longer, 1200' might not be enough to save my life.
4)3-4 seconds will put you out of luck for your reserve to inflate before your a meat waffle if your main malfuntions.

Disclaimer~ I do not have a AAD.If a skydive requires one then I shouldn't be on that jump.

MAKE EVERY DAY COUNT
Life is Short and we never know how long we are going to have. We must live life to the fullest EVERY DAY. Everything we do should have a greater purpose.

[btwitche1975 0]

I never said to apply a delay of four seconds at 750 ft. The four second delay migh be appropriate if the Dbag came out at 1500 though.

My point is the delay diminishes to zero as the dbag extraction tends toward the 750 ft floor.



Anyway there have been good points opposing this idea mainly centered aroud the loss of concrete predictable behavior and rigging complexity.

I,m tending toward thinking this is a bad idea too. I'll consider it an experiment in curiosty and chalk it up as another dumb one (They Happen)

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This is my rig... There are many like it, but this one is mine.
*/

[Cloudi 0]

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I,m tending toward thinking this is a bad idea too. I'll consider it an experiment in curiosty and chalk it up as another dumb one (They Happen)

Not dumb at all. At least you're using your brain.
What may turn out to be a bad idea in its original form, can lead to great ideas when continuing the thought in other directions.

Maybe someone will read your ideas/thoughts and come up with something really great, but maybe in a slightly different direction. It's happened before.

Kim
Watch as I attempt, with no slight of hand, to apply logic and reason.

[bob.dino 0]

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I'll consider it an experiment in curiosty and chalk it up as another dumb one

Thinking is a good thing, and it's pretty damn useful. I'm sure Helmut Cloth faced many doubters too. Just because we think there's holes in an idea doesn't mean that a) we're right, or b) they can't be fixed.

[MB38 0]

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I am pretty sure the Cypres brand AAD comes in 3 varieties: Tandem, Student, and Expert, each with its own corresponding logical firing altitude.

There is a fourth model, the "Speed" model for jumpers under extremely high performance canopies.

I really don't know what I'm talking about.

[phoenixlpr 0]

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There is a fourth model, the "Speed" model for jumpers under extremely high performance canopies.

AFAK there is a military model too.

I've seen rigs owned by the military, there are student cypres on those.

[BenediktDE 2]

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Scenerio 1:
*Diver pulls at 1200
...
Scenario 2:
*Diver pulls at 1000
...
Senario 3:
*Diver pulls at 800 (good luck)

The longest snivel I ever had was 1500ft - under my decision altitude of short over 1500ft I would not want to touch my main.

For every complex problem there is an answer that is clear, simple, and wrong.

[azdiver 0]

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Furthermore, if you lose altitude awareness you should know how to respond. If you wake up to the fact that you are in freefall at 1,000 feet go straight to your reserve, because this is an emergency, it is more reliable, and it prevents the dreaded/inconvenient 2 parachutes out scenario.

quick ? at terminal a reserve opening would be pretty hard wouldnt it scince its desinged to open fast, possibly knocking one out, would it maybe be better to have two one on main and one on reserve main set to fire off at 1500 feet or so, pulling at pull time still seems like the best thing though

light travels faster than sound, that's why some people appear to be bright until you hear them speak

• Quote

[mjosparky 3]

If you worry about having 2 out the best way to deal with that worry is just don’t go there.

With the present AAD technology you idea is probably not that practical. But keep thinking and you might be the one that changes “present AAD Technology”.

My idea of a fair fight is clubbing baby seals

[Guest]

Yea, not a bad idea...here's another one...

Since in this sport it seems that the simpler the gear, the more reliable, and cut-away cables seem relatively
cheap to buy...heck, if your cypress fires (even if your main is snivelling or not), just add 2 more cutters to the cypress to cut-away your main. Then, that would--most likely-- eliminate the 2-out scenario....but, it also adds complexity to the device...