Cypres not worked ?

[riggerrob 643]

ok. It's Saturday, it's cold & I'm bored...

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What is your point?

Saturday dawned cold and wet in Pitt Meadows.
I inspected three student mains, briefed a visiting jumper, caught a mis-routed chest strap, caught a tucked-under cutaway handle, tried out a new wingsuit, got complimented on my landing and hung a couple of canopies to dry. Then I took my girlfriend out for dinner and a movie.

You need to get out more often.
You need to find a girlfriend or get a hobby.

[riggerrob 643]

"Having to switching off a sentinel after your canopy opens ..."

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What are you babbling about now?

Between 1983 and 1999, I taught at several different schools that issued SSE Sentinel AADs to students.
I never told any student to do anything with an AAD after opening.
What was I missing?

[nathaniel 0]

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Between 1983 and 1999, I taught at several different schools that issued SSE Sentinel AADs to students.
I never told any student to do anything with an AAD after opening.
What was I missing?

http://www.parachutehistory.com/process/activation/sentinel.html

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Sentinel MK 2000 Operational Parameters:
fires when a jumper is below 1000 ft AGL AND has a descent rate greater than 30% of terminal velocity.
self test indicating system for battery and actuator cartridge
power ripcord actuating handle
Operation Procedure: At ground level, zero needle to "0". Just prior to exit, turn the red knob clockwise until the black quadrant seats in click stop and "arm" appears in quandrants window. After main is properly opened, turn quadrant until "off" appears.

The circuitry inside the cypres is smart enough that it rarely fires under controlled canopy flight. I've heard and read that the sentinel had a problem with sometimes firing after the canopy was open, and that it was thus recommended that you shut it off after your main was open. I could be remembering that wrong tho...

There are a few references to astras needing reset between jumps on dz.com if you do a search...maybe it's the astra in addition or instead of the sentinel that I'm trying to put my finger on...

Even though a cypres is electronic and needs to be turned off to conserve the battery etc, you often don't need to shut off, it will shut off automatically after 14 hours. IMO that's a definite human-machine interaction enhancement.

My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

[niu 0]

The rigs I started jumping in 1982 had Sentinels.The calibration was made on the ground ,and the only times I remember we were supposed to disconnect the cable to the actuator was in case of:A Landing with the plane B:water landings.
But they would for sure activate if used with todays canopies.Have a faint memory regarding misfires due to static electricity,but I think that was fixed before I used them.

[Liemberg 0]

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http://www.parachutehistory.com/process/activation/sentinel.html

What strikes me as funny is that I'm pretty sure that riggerrob (like me) can arm and disarm a sentinel without having to look at the manual (though I'm not 100% sure about myself for it has been a while...)

Can you?

(BTW: Rob is 100% right about students not disarming it under canopy, though I do remember something about water landings...first hand experience sinks in best, don't you think? - mine had fired, when I surfaced... AND: contrary to what was said in the above link you found, we used to arm them on the ground, prior to every students jump that was made... AND: Do you know why I NEVER would throw away a pulled reserve ripcord? Because my instructor is going to beat the shit out of me if I do... )
So much for 'googling' everything you wanted to know about parachuting but were afraid to ask...

"Whoever in discussion adduces authority uses not intellect but memory." - Leonardo da Vinci
A thousand words...

[mark 107]

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Having to switching off a sentinel after your canopy opens....

http://www.parachutehistory.com/...vation/sentinel.html

Sentinel MK 2000 Operational Parameters:
fires when a jumper is below 1000 ft AGL AND has a descent rate greater than 30% of terminal velocity.
self test indicating system for battery and actuator cartridge
power ripcord actuating handle
Operation Procedure: At ground level, zero needle to "0". Just prior to exit, turn the red knob clockwise until the black quadrant seats in click stop and "arm" appears in quandrants window. After main is properly opened, turn quadrant until "off" appears.

I'll bet Jan will be making a correction to that page soon.

That "operation procedure" is for the Sentinel-Sentry (or Sentinel/Altimaster?), not the Sentinel Mk 2000. The Mk 2000 does not have a zero needle, black quadrant, or windows (except for the red/green calibration lights. The Mk 2000's rate-of-descent sensor means it doesn't have to be turned off for normal (1970's - 1980's) canopy flight. In fact, there is no on-off switch, so if you want to turn disarm it for, say, an emergency descent in the aircraft, you have to physically unplug the control unit from the firing cartridge.

Mark

[mjosparky 4]

In responce to your last PM:

Did I say anything about the Sentinel? I am not blaming you for anything concerning the Sentinel.

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There's no tearing down in pointing out the limitations of a device.

You are not pointing the limitations because you do not know the limitations of the device. Take some of your extra time and read the manual. (Student activation seed is 29 mph)

The Cypres does an excellent job doing what it was designed to do. And that is to activate your reserve container if for some reason you don’t. It is not all things to all people nor is it designed to be a nanny.

If you feel there is a market for a device with different design goals go for it. Trying to over complicate the existing AAD would be like taking a Ford and trying to modify it to fly.

Door

My idea of a fair fight is clubbing baby seals

[billvon 3,111]

>To me, the fact that a human is capable of deciding when to open a parachute in all those cases . . .

Ah, but the fact is that sometimes humans FAIL to open a parachute in all those cases is an argument that sometimes a simpler algorithm is better than a more complex, intelligent one. We are excellent at complex decisionmaking but sometimes we screw up - which is why we can benefit from a backup that does not have the burden of all that uncertainty.

(Not to say that AAD's can't be improved - but an overly intelligent one could be as bad as an overly simplified one.)

[billvon 3,111]

> You need to get out more, find a GF or get a hobby.

Lay off the personal comments please.

[mjosparky 4]

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> You need to get out more, find a GF or get a hobby.

Lay off the personal comments please.

All posts are "personal comments".

The Forum Rules:
No personal attacks.

No jokes about or references to pedophilia. None.

No advertising in the forums.

Post to the correct forum and stay on topic.

My idea of a fair fight is clubbing baby seals

[nathaniel 0]

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sometimes humans FAIL to open a parachute in all those cases

And then we humans are experts in deciding and recommending a preferred course of action on these very forums. In many cases anyway...it's doubtful for instance that a machine could have improved the judgement of the poor fellow who flew into a bridge... And an aad will probably never unwrap a tangled parachute....

But these forums, in situations where an AAD could have or should have intervened, it seems human error is more an indication of human frailty than of insoluble physics. ie the inability of humans to 1) gather the correct sensory inputs and 2) put them together in a satisfactory way to choose when to open a parachute 3) do so.

The kiss principle is very valuable, agreed...but the final cause of the kiss principle is not to eliminate complexity wherever it is found...only wherever it is not needed.

My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

[nathaniel 0]

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And an aad will probably never unwrap a tangled parachute....

Question for the historians out there, has there ever been an AAD that integrated with a cutaway system? Or is there an overriding reason why this is a Bad Idea?

My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

[wmw999 2,587]

I'm not familiar with any. Even the SOS, which integrated cutaway with reserve pull, has fallen into some disfavor. There were two main reasons that I remember:
1. without the RSL installed, you could pull far enough to disconnect the main and not pull the reserve. If you had short arms, this was kind of easy to do.
2. the re-training when a student went to regular gear was considered somewhat risky -- the "old habits die hard" theory.

A cutaway pud with an RSL installed does the same thing for a student, while not hiding the inherent function from him. That can provide valuable cues to people who think as they go, rather than simply doing what they have practiced. A system that coexists comfortably with both types of people is better than one that favors the memorizer or the think-it-through type.

That's my memory. As a qualifier (since I'm sure you'll find something wrong with that), I was a very current jumpmaster and instructor in the late 1970's and early 1980's, just as gear was transitioning to piggybacks with SOSs on them. The DZ I was at went through that transition.

Wendy W.

Wendy W.

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)

[nathaniel 0]

If there were 2 more cutter heads, on the loops that terminate the 3-rings, you'd want to make absolutely sure that they both cut if either was...and that the reserve was fired all at once. One or two of three heads would be Bad...reserve only is the situation we've got right now with current models.

In what other ways could 3 cutter heads, (reserve, 3ring, 3ring) fail? There are probably also other ways to arrange for an aad to cut a main canopy away as well...

My advice is to do what your parents did; get a job, sir. The bums will always lose. Do you hear me, Lebowski?

[tso-d_chris 0]

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-Turning the device on and off should NOT be made easier. It was purposely made more difficult to improve ergonomics (i.e. to avoid inadvertent setting)

That's unjustified. And possibly unjustifiable, imo. There's not even an explicit need for an on or off at all, since this concept is redundant with whether it ought to fire.

Unless you are talking to a swooper who is about to go big on his next hop & hook, in which case the ability to be able to turn off the CYPRES could in fact be very important.

[LawnDart21 0]

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If there were 2 more cutter heads, on the loops that terminate the 3-rings, you'd want to make absolutely sure that they both cut if either was...

2 Points:
1) I would NEVER trust an AAD with the job of cutting me away from my main, EVER. There is a point of simply giving up too much control, and that crossess the line. What happens when someone on a cell phone near the landing area causes the 3 ring aad to fire at 100ft? Build it and it WILL happen. (maybe not by a cell phone, but it will happen).
2) While your at it, why not create an AAD that opens the main too? You want to remove human error from all aspects of emergency procedures, why not build an AAD for the main too? You could even buld a packing machine for mains, so that main malfunctions will never happen.

Your quest for creating a better back up in aads, while an admirable intent, is missing an essential component of skydiving: WE ARE RESPONSIBLE TO SAVE OUR OWN LIVES.

We are responsible to open our mains.
We are responsible to follow through our EPs if we experience a malfunction
We are responsible for performing our EPs at an appropriate altitude to allow our reserve to inflate.

No amount of magical AADs will ever change that.

--
My other ride is a RESERVE.

[riggerrob 643]

... has there ever been an AAD that integrated with a cutaway system?

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Helmut Cloth's original proposal for the Cypres included: releasing the drogue, cutting away the main, opening the reserve, etc.
However, that many variables boggled Helmut's mind, so he decided to focus on a reserve-only AAD.

No-one else had been bright enough to design a sport AAD that does anything more than open a reserve container.

Well, a few ejection seat AADs sequence: seat belt tightening, canopy ejection, mortar initiation, rocket firing and steering, drogue deployement, seat separation, canopy deployment, etc. but they start with far fewer parameters and cost "slightly" more than your average skydiver is willing to pay.

KISS: keep it simple skydiver.

[mark 107]

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[H]as there ever been an AAD that integrated with a cutaway system?

I vaguely recall that Cypres was designed with this capability, but not produced. There are some tantalizing Google hints (dead links here and here), one of which includes Bill Von's name. Perhaps he can remember the gist of that rec.skydiving exchange 10 years ago -- or perhaps AirtecKai or Helmut can chime in here.

Mark

[wmw999 2,587]

Once you get into multiple cutter heads you probably have to start with some redundancy management algorithms, because they have to operate in a specific order, and with specific timing. Catastrophic results can happen if these automatic things don't go exactly as planned. There are thousands of lines of tightly-packed code to manage the space shuttle's three main engines. Yes, they are more complicated. However, the individual under the single system with 3 cutters is probably not going to be any less interested in the outcome.

Even the 2-pin Cypres is more complicated than the single pin one, and the only dependency there is that both of them need to operate for the AAD to have its function. If that doesn't happen, the reserve will continue to operate as it should; it's a fail-safe system, but it's only one failure deep.

Until the redundancy and timing management software has a lot more shelf life (no blue screens of death, thank you very much), I would not be interested in having it involved in something that can be overcome with training for the vast majority of people, and with currently-functioning or similar AADs for the vast majority of the rest.

If you want to improve AADs, make them more likely to be used -- improve the verification and shelf life on the current software, so that the lifespan becomes a thing of the past, and the calibration. Improve the cost. Make them more moisture-resistant, and more shock-resistant, because people will continue to pound on their over-full rigs.

A lot of thought has clearly gone into the current ones; they are not perfect, but neither are they at the any-idiot-can-see-the-problems bad. It's just that with more people skydiving, there is a bigger chance of that one person in a thousand who misunderstands instructions will skydive.

Better education about the altitude mode. Maybe having a speaker that emits a beep if it detects a change in field elevation (of course, when you jump and land at different places that can be annoying). I also kind of like the current turn-on-turn-off scheme. A whole lot of thought went into what is most likely to fit into what real people do comfortably most of the time. That's the essence of human-machine interface.

Anyway, this post is way long. But, well, I work on human-rated software for a living, and just had to pontificate for a couple of minutes.

Wendy W.

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)

[tso-d_chris 0]

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You use words like ergonomics and say how the VIGIL was better, but your example device has CAUSED accidents.

While I understand your point, I have to point out that while the ability to change modes offered the opportunity for error, it was the lack of a thorough gear check that allowed the skydive to take place with the AAD in an improper mode, at least if we are talking about the incident involving a high profile world champion skydiver.

For Great Deals on Gear

[Ron 10]

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While I understand your point, I have to point out that while the ability to change modes offered the opportunity for error, it was the lack of a thorough gear check that allowed the skydive to take place with the AAD in an improper mode, at least if we are talking about the incident involving a high profile world champion skydiver.

Yes and it kinda proves my point. Making a device with multi-modes ADDED a step that was not needed, or at the very least complicated a step. People are going to make mistakes...If they didn't we would not need an AAD.

But the more things you pack onto an AAD the more chances of something going wrong.

The CYPRES was so popular since it was so easy to use. The Astra had some features that made it never take hold since it was more difficult to use.

Adding features that can cause accidents is not a step forward. Yes accidents that could be avoided if people payed attention....But if people payed attention AAD's would not be needed at all.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

[Ron 10]

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In what other ways could 3 cutter heads, (reserve, 3ring, 3ring) fail?

We have misfires now....Imagine a misfire that cut away one riser?

Again, adding stuff just makes the opportunity for more problems.

"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334