Adjusting Cypres firing height for Comfort

[velo90 0]

groundrushpull Wrote

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Please explain to me how it would be BAD to set ones cypress lets say 90 or 120 feet (30 foot increments) higher so that it will activate (fire) around 850 feet instead of 750 feet?

Because one day you get it wrong and it fires lower instead of higher.

Because on your next low pull your reserve fires into the main.

Because on your next jump when it is supposed to fire it thinks you are only 120ft above the ground and does not, the true 240ft might have just have saved you. (figures approx)

You are right, it's your life, but at my Dropzone I would be very wary of someone who was adjusting their cypres just to make it fire higher. Mainly because I could see no valid reason for it.

Give me a reason other that you be happier hanging on your reserve 90 -120 ft higher and I might buy it.

I have seen experienced jumpers having all sorts of problems adjusting their cypres. I would hate people to get the idea that this can be done lightly.

Dave

Edited to add:
I moved this discussion over from incidents but I will probaly still get shouted at by SkyMonkey because it should be Gear and Rigging.
Decisions decisions....

[FrogNog 1]

Wouldn't it be simpler and more dependable (if less flexible) to get the student model of cypres, and simply cease all wicked maneuvers by 1250 feet? (I guess this would rule out swooping.)

Having just come off student status, I am of course biased toward the student cypres. :)

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Pull.

[velo90 0]

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Wouldn't it be simpler and more dependable (if less flexible) to get the student model of cypres

What makes a Student cypres more dependable?
What makes it less flexible?
Both versions are just as dependable, it's just that the student versions have different firing parameters that more suited to student jumping.
With my VX I don't think I would even need to turn more than 90° to get a student version to fire (hardley a wicked maneuver).

[AndyMan 7]

Adjusting your Cypres for any reason other then a different elevation at landing area seems like an extremely bad idea.

Remember that Cypres's can fire upwards of 1000 feet based on the orientation of the jumper... If they're in mid-snivel, for example. I would not like to see this raised to 1,200 feet, given that I've pulled at 2000 feet after big-way RW and have 800 foot openings. Increasing the odds of 2-out malfunctions just because someone is uncomfortable with jumping WITH a Cypres seems odd to me.

Cypres's are good, dependable devices which have proven themselves over several years. Don't screw with it.

_Am

__

You put the fun in "funnel" - craichead.

[mr2mk1g 10]

Lets say you set the cypres so it thinks your landing 250ft higher. Theres a warning in the manual that says that once you have gone above 250ft the plane cannot go back below that altitude. The cypres thinks you just flew underground. I know it would be rare for a jump plane to do this but it does happen.

I dont remember what the ramifications were... might just be that the cypres re-set... someone will have to confirm...

Edit: found it in the online manual - this will "lead to a low, or no activation" ... so by fiddling you just switched your cypres off.

[FrogNog 1]

> What makes a Student cypres more dependable?
> What makes it less flexible?

I meant that using a Student cypres instead of an Expert cypres set to a higher altitude is more dependable in that the "alternate" altitude setting would be more dependable. That is, using a Student cypres at its default setting to get a 1,000 foot cypres fire would be more "dependable" than using an Expert cypres with a +250 setting to get a 1,000 foot cypres fire because the human factor of adjusting the fire height is removed. Just blink it three, sit back and watch it count, and all done.

The "inflexibility" is also comparative; a Student cypres left at its default setting will of course always be set for the same altitude, and that will also always be 1,000 foot. The question originally posed asked for a 150 foot raise, not a 250 foot raise, so the Student cypres (left on its default setting) is not fitting the bill precisely. If the person in question decided all of a sudden that he wanted it raised by 50 feet or 400 feet, again the Student cypres (left on its default setting) would not match exactly - hence my labeling that solution "inflexible."

Personally, I dislike the idea of custom-setting a piece of life-saving equipment every time I jump, especially if there is a decent possibility that I could be setting it "worse than normal" as easily as "better than normal." Just give me something that works the way I want it to without custom settings, and I'll practice turning it on and verifying it works normally every jump.

And, yeah, the lower vertical speed bar to fire the Student cypres would probably totally prevent swoopage. There may be napkin canopies small enough that full forward flight might set it off.

I think the best thing to do to make a cypres fire 150 feet higher is pull 150 feet higher yourself. You should trust your own pull ability far more than the cypres.

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Pull.

[billvon 2,991]

>That is, using a Student cypres at its default setting to get a 1,000
> foot cypres fire would be more "dependable" than using an Expert
> cypres with a +250 setting to get a 1,000 foot cypres fire because
> the human factor of adjusting the fire height is removed.

If you forget to pull, the student cypres fires at exactly the same altitude as the expert. From the user's guide:
-----------------------------------
The Student CYPRES can be recognized by the yellow button with the imprint "Student"on the control unit. It will activate the EOS when the rate of descent exceeds 29mph (13m/sec).

The activation altitude is split. In the case of rate of descent being equal to that of freefall the opening altitude is at approx. 750 feet, being the same as with Expert CYPRES. However, should the rate of descent be lower than that of freefall but still above the limit of 29mph (e.g. with partially opened canopy), then Student CYPRES activates the EOS when the altitude decreases below 1000 feet above ground level. The student will then have some more time to prepare for landing.
-----------------------------------------

>The "inflexibility" is also comparative; a Student cypres left at its
> default setting will of course always be set for the same altitude,
> and that will also always be 1,000 foot.

750 feet actually. See the cypres user's guide for more info.

[FrogNog 1]

Ah. I didn't know that the Student model cypres does not have its firing altitude entirely moved to 1000 feet. I'm also very glad to have heard this after I'm off student status.

In fact, now I feel better that the expert cypreses I jump with now will provide me the same coverage I was expecting from the student models.

So, I have to retract my suggestion of using a student cypres, because now I see it doesn't buy him anything.

Maybe he should find a dropzone where the runway is on a lone 150 foot hill. :)

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Pull.

[Reginald 0]

There are a couple of issues here I want to comment on and/or ask questions about.

First, the student Cypres is set to fire at the same altitude (750 AGL) as the expert! Well technically the altitude is split at either 750 in free fall or 1,000 at sub free fall. The difference is primarily in fall rate NOT altitude. FYI the tandem is set to fire at 1,900. This appears to be a very popular misconception. Go to the http://www.cypres-usa.com/english_users.pdf site and read up on it.

Second, I have talked to a dozen instructors and “sky gods” that should darn well know the parameters of the Cypres and its variants, expert, student and tandem. I got a dozen different opinions on the firing altitude for the different versions. It sacred me into reading up on it myself. Why do so few people know the parameters? I think this is something anyone wearing one should know. I don’t mean to knock anyone here but when I got so many different opinions from so many different people it made me think there is a dangerous lack of equipment knowledge in the community over AAD’s.

Third, when I hear about Cypres fires it is also usually followed up with a severe injury report. It makes me think that the firing altitude of 750 may be a bit shy of optimal. Why not 1,000? This question was further complicated when I looked at an Astra AAD. It is set to fire at 1,000. Its manufacturer notes that in “real” world conditions 1,000 is the lowest level to safely have the reserve deploy to avoid the possibility of sever injury.

Fourth, why are Cypres’ the gold standard? I am looking at buying some used gear that has a Astra. Should I consider replacing it with a Cypres?

Thanks all!

Ron

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[PhreeZone 20]

>Third, when I hear about Cypres fires it is also usually followed up with a severe injury report.

I've seen 4 Cypres fires in 3 years (WFFC... don't ask ) and every single one of them ended up being a nice soft landing that the jumper carried their gear away from.

Do a search on the Astra vs Cypres things. The differences are enough that it requires a lot of research.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[Reginald 0]

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>Third, when I hear about Cypres fires it is also usually followed up with a severe injury report.

I've seen 4 Cypres fires in 3 years (WFFC... don't ask ) and every single one of them ended up being a nice soft landing that the jumper carried their gear away from.

Great! That is what I want to hear!

"We've been looking for the enemy for some time now. We've finally found him. We're surrounded. That simplifies things." CP

[FrogNog 1]

Cypreses are treated like a gold standard because they have been around longer, and people have more exposure to them.

Personally, my studenthood was always jumping with a Cypres AAD, not any other. All my jumps were uneventful from an AAD standpoint, but when it comes time for me to pick an AAD, I know what a Cypres looks like, how to turn it on, and I have jumped with this mystical creature attached somewhere to my back a few dozen times and it hasn't hosed me yet.

I was instructed that the Cypres was the first of the "current generation" of AADs; that all AADs that came before it were inferior in significant ways, and that the Cypres was the first one that had such good reliability doing its job when it should and not doing its job when it shouldn't that the tide on AAD use began to turn based on basically this performance record alone. I know of few or no facts to back this assertion up; it's just what I was told / the impression I got based on what I was told.

I think also a lot of mysticism comes with an AAD, because for better or for worse, sport jumpers are not in position to seriously test all aspects of their AADs operation. (To do so would be suicidal.) So we have some natural superstition about whether one AAD is better than another.

-=-=-=-=-
Pull.

[sundevil777 102]

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I am looking at buying some used gear that has a Astra. Should I consider replacing it with a Cypres?

In my opinion, yes.

This is an example of a thread that you might check out:

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=453080;search_string=astra;#453080

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[velo90 0]

[replyI think the best thing to do to make a cypres fire 150 feet higher is pull 150 feet higher yourself.

[Tonto 1]

Excellent post.

t

It's the year of the Pig.

[groundrushpull 0]

Actually Dave although I did not state this on my original posts to try and avoid all these arguments about personal preferences to gear choices etc.
I would ALWAYS SET MY CYPRESS TO A LOWER FIRING ALTITUDE THAN THE DEFAULT!...Now I am sure to be once again damned by many of you who know what is right for me and everyone because it is right for them! I don't jump a cypress anymore because the manufacturer played their little marketing games with everyone after they became the AAD of choice and then released the OH YEA THEY WON"T BE ANY GOOD AFTER 10..UH I MEAN 12 YEARS-para-phrased...SO WE CAN SELL EVERYONE NEW ONES$$$.
I remember all the significant numbers people came up with after the 911 tragedy and i guess we can all come up with various altitude scenarios that can justify setting the activation altitude either higher or lower or whatever. JUST IMAGINE the possibilities.

you wrote:
"I have seen experienced jumpers having all sorts of problems adjusting their cypres. I would hate people to get the idea that this can be done lightly."


If there are experienced skydivers that have problems with using their own equipment that would suggest more training. The cypress is actually a simple device to operate once shown in that it ONLY HAS ONE BUTTON AND ONE DISPLAY TO UNDERSTAND!

You wrote"You may want prefer it, if your cypres fires 150 ft or indeed 400 ft higher. BUT, to acheive this by calibration of the landing height before a jump is NOT the answer."

So what is the answer?

As far as Astra/cypres and now the VIGIL AAD I am glad there is more real competition in the AAD market for all of us consumers!

Cypres set their "decision altitude" for their device at 750 ft. What if 13 or so years ago when they intorduced the cypres the default altitude was 900 feet then we would be using that number in our dicussions to not do this because of that. It is all relative. They are good but not GOD.
Informed decisions,
decisions,
decisions!

John Maggio

[billvon 2,991]

>I would ALWAYS SET MY CYPRESS TO A LOWER FIRING ALTITUDE THAN
> THE DEFAULT!...Now I am sure to be once again damned by many of
>you who know what is right for me and everyone because it is right for
>them!

You can set it to whatever you like, but unless you've got some drop test data I don't think anyone will take your altitude setpoint as anything but a wild guess.

>I don't jump a cypress anymore because the manufacturer played
>their little marketing games with everyone after they became the AAD
> of choice and then released the OH YEA THEY WON"T BE ANY GOOD
>AFTER 10..UH I MEAN 12 YEARS-para-phrased...SO WE CAN SELL
>EVERYONE NEW ONES$$$.

PD does the same thing with their reserves - limit their life based on repacks and/or usage. Do you refuse to jump PD reserves?

In any case, if the cypres timeout thing bothers you, get your rigger's ticket and use your cypres for as long as you want.

>Cypres set their "decision altitude" for their device at 750 ft. What if 13
>or so years ago when they intorduced the cypres the default altitude was
> 900 feet then we would be using that number in our dicussions to not
>do this because of that. It is all relative. They are good but not GOD.

I agree; however, the 750 foot number was arrived at by doing lots of testing. It's like saying "I can overload our Cessna by 500 pounds; I've seen overloaded 182's get off the ground. Cessna isn't god. It's all relative." Maybe so, but they know far more than most pilots about how much weight their aircraft can safely carry.

[velo90 0]

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So what is the answer?

In your case, I would say do not use cypres or find an AAD that is designed to fire higher or lower than cypres.

I will stick with cypres, from what I have read and seen, it seems to work just fine.