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drenaline

Turning on cypres Q

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I was thinking about this last time I turned my cypres on, do you think it is dangerous to turn on the cypres while been in front of the reserve flaps?

maybe the cypres can fire while reseting and get a nice reserve pilot chute hitting your chest or face.

HISPA 21
www.panamafreefall.com

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I was thinking about this last time I turned my cypres on, do you think it is dangerous to turn on the cypres while been in front of the reserve flaps?



No.

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maybe the cypres can fire while reseting and get a nice reserve pilot chute hitting your chest or face.



Maybe it can, maybe the reserve closing loop could snap too. In a world where nothing is certain we need to plan for what is likely. I think, given the documented history of the Cypres, that it is very unlikely a unit will misfire while being powered on. However, if it makes you feel safer by pointing the reserve away from you when you power on your Cypres, then by all means, do it.

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Jim
"Like" - The modern day comma
Good bye, my friends. You are missed.

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I was always taught to turn cypress on while it's pointing away from me - not in case of a misfire - but while it's self-testing, I check the reserve pull cable can slide through the steel casing (occaisionally small rocks get up there and jam the cable from sliding through smoothly).

Extremely unlikely (IMO) that a cypress would go off, but even less likely that a reserve deployment in your face on the ground would kill you. Sting yes, but the spring isn't all THAT powerful.
Trapped on the surface of a sphere. XKCD

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but even less likely that a reserve deployment in your face on the ground would kill you. Sting yes, but the spring isn't all THAT powerful.



I think the only thing it would hurt is your pride, as everyone laughs at you.
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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When changing DZ do you have to do anything special to the Cypress? i.e. you jump in FL and go to a DZ in AZ w/ your rig. Or do i just turn it on and jump?



Nothing special, just turn it on and jump. When it turns on, it calibrates itself to ground-level. As the day progresses, it will keep sampling the pressure and will stay calibrated during normal weather-induced barometric pressure changes.

Now, if you decide to turn it on at your DZ and then fly out to an area with a different elevation to make your jump it will not be accurate. It only knows where 0-feet AGL is for where it was before takeoff.

You will have to manully program in the offset for that type of jump. It is actually pretty simple to do.

Kris
Sky, Muff Bro, Rodriguez Bro, and
Bastion of Purity and Innocence!™

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Works the same wherever you are.

One rare thing that can happen when going to a new DZ - rarely, but it can happen - a landing area might be at a different elevation than the hanger - it might be 500 feet of difference if the landing area's a long way away, so ask the person giving you a briefing if the hanger and landing area are at different elevations. If so, you may want to turn the cypress on in the landing area, and not at the hanger. Don't do it behind the plane, though - the pressure difference with the engine exhaust will throw off a cypress too.
Trapped on the surface of a sphere. XKCD

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If so, you may want to turn the cypress on in the landing area, and not at the hanger.



Uh, no.

The Cypres samples air pressure at the ground every 30 seconds, by the time you've made it back to the loading area they Cypres will consider that to zero AGL. READ the Cypres manual, there are detailed instructions on how to deal with an LZ at a different elevation from the loading area.

Don't have your manual? Try here: http://www.cypres-usa.com/

While you're there be sure to look around, there's lots of other valuable information about the Cypres, things you should know.
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Jim
"Like" - The modern day comma
Good bye, my friends. You are missed.

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Are we reading the same manual? Mine sez this:


4.3 When to switch on or re-set
CYPRES measures and locks in the altitude at the site where it is activated.

As well as this:

When the airfield and dropzone are in different locations and at different elevations,
CYPRES must be switched on at the departure airfield and adjusted to the elevation of
the dropzone


It does sample every thirty seconds for weather changes, but I think it's smart enough to know the difference between pressure changes due to weather and elevation. Something to with delta rate of change perhaps? Those Germans can be pretty smart.

Am I missing something here?
Trapped on the surface of a sphere. XKCD

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Jimbo is right.

What they're trying to say is that you must turn it off, then back on, adjusting for altitude deviation at the departure airfield, meaning the takeoff elevation.

You can only adjust for altitude deviations during the power-up cycle. After every landing and trip back to the take-off altitude, you must turn it off then turn it back on adjusting the unit during the power-on cycle.

If you turn it on at the landing area, it WILL sense the altitude change as you head back to the take-off altitude.

_Am
__

You put the fun in "funnel" - craichead.

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Oh, I see! I was assuming hanger (where I always turn mine on) is at one altitude, while takeoff and landing area (I assumed the same altitude for both) are at a second altitude. So what I was trying to say is turn it on at the takeoff area, and not the hanger.

But I see that you are saying the takeoff and landing area can be different altitudes, which is all that really matters from the standpoint of the cypress. It doesn't really care about the hanger (since it doesn't drink beer). In that case, it again makes sense to turn it on near the plane, and not where you land, then adjust for estimated altitude difference.

I've seen places where the takeoff/landing area are at one altitude and the hanger at a different altitude, which is why I posted. I've never seen takeoff and landing area at different altitudes, but I certainly believe it's possible - I guess more for demo jumps than regular DZs. But I think we were all trying to say the same thing - in the case of different altitudes, turn it on by the plane, then adjust as necessary.

Thanks for helping clarify a fine point. I'm always amazed, given the complexity of the machine, that it only has one button. Must've been designed by Mac users.
Trapped on the surface of a sphere. XKCD

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I've seen places where the takeoff/landing area are at one altitude and the hanger at a different altitude



Just out of curiosity, hangers are usualy used to store planes, and tend to be close to runways. In what case would the hanger be at a different altitude then the runway?

_Am
__

You put the fun in "funnel" - craichead.

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Nice Hijack(spelling?)! B|

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After every landing and trip back to the take-off altitude, you must turn it off then turn it back on adjusting the unit during the power-on cycle.



That is correct, but I don't think you will find dz that the landing place is at different altitude than the takeoff place. Now that will sure squeeze the life out of your batteries in no time. The setting of altitude is usually needed when doing demo jumps or when going from one airport and jumping in another airport that has different elevation.

Hey one good Q (me hijacking myself?) what about balloon jumps, is it wise to turn on the cypres? you never now what the elevation of the landing zone will be.

HISPA 21
www.panamafreefall.com

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Unless you are headed into hilly country its not a bad idea to have the Cypres on. You should be tossing fairly high anyways to let you set up for landing. If you take off low and are headed uphill and are worried about it going off at only 300 feet instead of 750, bump it up a few hundred. If you take off from a mountian top and will be exiting over low lands, then lower it. You need to be at least semi fimiliar with the land that you will be flying over in the balloon, ie mountian rage, huge valleys etc. If you know whats in the general direction... everything else is easy to figure out
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And tomorrow is a mystery

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