Cypres activation question

[skydiverek 58]

Taken from the reviews:

"Cypres Expert, which decides at 1000ft to activate at 750ft if the parameters have been met (a person who deploys at a low altitude and snivels through 1000 ft at a speed greater than 78 mph will get a reserve opening at 750ft even if their main canopy is fully deployed at 900ft).".

Is this true???

[Mostly_Harmless 0]

Yes. I believe the cypress is acurate within +/-200 feet. So at any time you are passing the activation window at 78 mph, canopy out or not, it will fire.

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[phoenixlpr 0]

Yeah. This is the root of the cypres fires.

Its not so wise to play around the Cypres activation altitude.

I have seen a 3way speed start from 1000m. One of them ended up with a 2 out/side bye side due to a his Cypres fired.

[PhreeZone 15]

Contact Airtec directly and ask them your question. There are lots of "expert opinions" on the fourms about peoples thoughts on how the CYPRES works, but Airtec will tell you just how accurate it is, its limitations and its weaknesses.

There is a precieved fall in altitude when you transition from belly to Earth to sitting/standing up because the low pressure that developed in your back disappears and AAD's see that loss of pressure as continuing in freefall. Airtec can tell you just how much this pressure affects the CYPRES. www.cypres.cc

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[fcajump 153]

Quote

Taken from the reviews:

"Cypres Expert, which decides at 1000ft to activate at 750ft if the parameters have been met (a person who deploys at a low altitude and snivels through 1000 ft at a speed greater than 78 mph will get a reserve opening at 750ft even if their main canopy is fully deployed at 900ft).".

Is this true???

Phreezone is correct in approach.

For me, I consider a Cypres fire anywhere under 1200' to be MY fault. Between exit alt, deployment altitude, and EP deck... if it fires below 1200', I considered that I messed up somewhere.

JW

Always remember that some clouds are harder than others...

[sundevil777 94]

Quote

Taken from the reviews:

"Cypres Expert, which decides at 1000ft to activate at 750ft if the parameters have been met (a person who deploys at a low altitude and snivels through 1000 ft at a speed greater than 78 mph will get a reserve opening at 750ft even if their main canopy is fully deployed at 900ft).".

Is this true???

The answer is definitely NO.

The unit has some ability to be fooled by changing air pressure due to orientation, but to say that it decides at 1000 to activate at 750 is not true.

Others are answering a question that is different than what you asked.

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

[phoenixlpr 0]

Quote

2.1 Expert CYPRES
The Expert CYPRES can be recognized by the red button on the control unit.
It activates the EOS when it detects a rate of descent higher than 78 mph (35 m/sec) at
an altitude of apx 750 feet above ground level (AGL). In the event of a breakaway below
this height CYPRES will operate down to apx 130 feet AGL. Below 130 feet AGL opening
is no longer useful. For this reason, CYPRES ceases operation below apx 130 feet AGL.

From English Cypres manual, page 10.

[USPA 0]

Is the correct answer.

(only to add to directly answer your question: Your answer would be "No". The cypres does not decides at 750ft, but it's reading can be fooled)

The trouble with skydiving; If you stink at it and continue to jump, you'll die. If you're good at it and continue to jump, you'll see a lot of friends die...

[jurgencamps 0]

Quote

"Cypres Expert, which decides at 1000 ft to activate at 750 ft

Not true: it decides to fire and fires in milliseconds, not 250 ft higher.

Quote

a person who deploys at a low altitude and snivels through 1000 ft at a speed greater than 78 mph will get a reserve opening at 750ft even if their main canopy is fully deployed at 900ft)."

when you are on your belly, the cypres decides to fire and fires at 750 ft if you are still going faster than the activation speed,
when you are in a standup position, the cypres decides to fire and fires at around 1000 ft instead of 750 ft if you are still going faster than the activation speed.

Quote

Is this true???

Ask airtech (their response at this question has been posted several times here at this website.

Gr

Jurgen

PS please keep us informed about their response.

[Dionysus 0]

I contacted Airtech some time ago with this very question. The answer I was given, IF memory serves me correctly, is that there is no programmed delay between having the firing parameters met and the actual firing. Meaning the Cyres does not decide to fire then wait then actually fire.

However the Cypres is, if I understand it correctly, designed to fire at 1050ft air pressure altitude. Since the Cypres could be in your burble which will give a higher air pressure altitude reading than your actual altitude it works out that if you are on your belly it will fire at approximately 750 feet actual altitude. If you are not on your belly and air pressure altitude as measured by the Cypres is roughly the same as your actual altitude than it can fire as high as the 1050 ft. That is why some people can experience a two out if they sinvel through the 1050 ft mark with enough vertical speed.

Another way of looking at it is that at 750 ft actual altitude, on your belly, an air pressure altimeter such as a Cypres, Neptune, Alti2 ect will read approximately 1050ft on your back. Take the altimeter out of the burble and the pressure altitude and the actual will be approximately the same.

A neat trick to see this is to fly on your back with a wrist mount altimeter. First take a look at the altimeter while it is in the airstream then bring it into your burble, stomach area, and you will indeed according to your altimeter go up.

Anyway I would urge you to contact them directly. They are very helpful folks and seem eager to answer any questions.

[jurgencamps 0]

Dionysus,

Your memory and your answer is correct.

Jurgen

[Dionysus 0]

Thanks! Normally my memory sucks so it's nice to hear that.