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GoHuskers

Anyone ever heard of a cross ported Spectre?

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Yes it is common, it is on all of them.

Although your post is much calmer than most. Most of the posts about this question involve some sort of "ZOMG MY CANOPY HAS A HOLE IN IT" variation.:P
--"When I die, may I be surrounded by scattered chrome and burning gasoline."

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I was a little freaked out but I called my rigger right away. It looks torn but it runs through every rib and connects some cells together. All in the same place between the A and B lines. There are always some (not every cell) about midway through the cell.

Is this common for canopies in general or mostly used for crew?

I'm taking it in to the DZ tomorrow to get a full inspection regardless.

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It's quite normal. It allows the air pressure to flow between cells inside the canopy to equalize across the entire area. So if one cell collapses, like an end cell, air from adjacent cells can flow through those crossports to re-inflate it from inside out, without having to depend solely upon air entering the nose. Nature abhors a vacuum, and high pressure air will flow to fill a low pressure area.

Back in the old days some canopies didn't come with crossports, and some jumpers would heat up empty tin cans of various sizes on the kitchen stove and melt their own holes in the ribs to create home-grown crossports.

Disclaimer: I'm not an aerodynamic engineer.

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My wife bought a spectre from the classifieds. It has holes between the ribs and some holes between the cells. My rigger is going to look at it tommorrow but I was curious if this is common for Spectre 150's



Don't worry about it dude. They're there by design on pretty much every modern canopy - part of the whole 'staying inflated' thing. ;)

Good job on looking and asking though. Never stop doing that!

As an aside, you're at nearly 70 jumps now - time to start learning as much about your gear as possible. Rather than just having your rigger look over these holes, why not arrange a time for you and your wife to get a lesson in the details of the gear your jumping with him? Take over some beers at the end of a night and spend a few hours with him going over detailed stuff? Design parameters for canopies, line lengths, reason for brake settings, stitch patterns, checks you can do...

It'll all be really useful info.

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Are there any non-crossported modern canopies?



I don't believe I've ever seen a cross ported round. (and yes, there ARE modern rounds)
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Are there any non-crossported modern canopies?



I don't believe I've ever seen a cross ported round. (and yes, there ARE modern rounds)



Even the old round canopies had intentional holes in them, to vent air. The apex had a hole to keep the canopy from oscillating, and other holes were placed around the skirt for steering and forward drive.

And some ram-air accuracy canopies have two holes in the bottom skin, so that when in a straight-down deep sink, air can flow into the canopy from underneath the canopy, since there's no forward drive to ram it in the nose.

It seems that holes in parachutes have always been quite natural, and necessary! Go figure!

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Are there any non-crossported modern canopies?

As I understand it, cross ports are very important in determining the opening characteristics of a canopy.

DaVinci



Yes.

Reserve canopy called "Transfair" (from PdF)doesn't have them at all.

Speed 2000 from Paratec (also reserve) doesn't have crossports on the center cell (2 loaded and 1 non loaded rib).

Raven reserve from Precision doesn't have them on the midle non loaded rib.

VTC 2 360 (tandem reserve) from RWS/UPT doesn't have them on the middle 3 cells.

This is from my memory .
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

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Heh. I also quite liked the "I don't like canopy X because their ribs are not fully ZP, so I have canopy Y" comment that got made in this forum a while back.
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"I'll tell you how all skydivers are judged, . They are judged by the laws of physics." - kkeenan

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That's very interesting. Is it because they are designed with big open nose inlets and cross-porting would lead to excessively fast openings or some other reason of benefit to reserves (maintaining heading on opening, perhaps?)



Dunno, but I have a few rides on my previous Transfair (128sqft, at ~1.2 WL) and it opened fairly soft especially compared to the newer Techno, in fact I had closed endcells on 2 of the rides :S

ciel bleu,
Saskia

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As an aside, you're at nearly 70 jumps now - time to start learning as much about your gear as possible. Rather than just having your rigger look over these holes, why not arrange a time for you and your wife to get a lesson in the details of the gear your jumping with him? Take over some beers at the end of a night and spend a few hours with him going over detailed stuff? Design parameters for canopies, line lengths, reason for brake settings, stitch patterns, checks you can do...
It'll all be really useful info.



Well observed. Do you have a book recommendation for explaining parachute gear?

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As an aside, you're at nearly 70 jumps now - time to start learning as much about your gear as possible. Rather than just having your rigger look over these holes, why not arrange a time for you and your wife to get a lesson in the details of the gear your jumping with him? Take over some beers at the end of a night and spend a few hours with him going over detailed stuff? Design parameters for canopies, line lengths, reason for brake settings, stitch patterns, checks you can do...
It'll all be really useful info.



Well observed. Do you have a book recommendation for explaining parachute gear?



Don't look for a book. Look for people to teach you.

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when I had ~15 jumps I bought a well used Saber 170 (totally airworthy, but older) and after a few jumps on it one of the packers at good 'ol mile high told me "you're not jumping that thing again, the cells are blown up", I protested and told him that those are cross-ports, essentially every ram air canopy ever built has those holes. He went and asked an instructor, and no shit. Those are supposed to be there.

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My Unit number 26 arrived it had a note that saidWe are not allowed to crossport because of patenr rights. We have drawn circles where you should hot knife them." If you have a sniveller add a small set across the back ribs. It was common to put a larger and larger hole in your slider until you got the opening you wanted.

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