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Industry info relevant to PCsize/opening thread

 

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3ringheathen  (D 18302)

Dec 21, 2003, 4:53 PM
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Industry info relevant to PCsize/opening thread Can't Post

http://www.performancedesigns.com/docs/hrdopn.pdf


Selected exerpt, read it yourself for more details!:


PILOT CHUTE
The pilot chute has a big effect on canopy deployments. The size, type of fabric, length of bridle, apex length, mesh size, and aerodynamic shape
all affect the deployment of the parachute. Some pilot chutes have too much drag at terminal velocity. This can cause these problems:
1. They slow the bagged canopy down so quickly that the chance of line dump is increased.
2. When reaching line stretch, the jumper instantly accelerates the canopy back to his speed, since it is attached to him by the fully deployed lines....


...A pilot chute with more moderate drag will get the canopy to line stretch with less severe shock to the jumper and the canopy. The line dump
problem is also less likely to occur, and the pack job is more likely to be released from the bag in an orderly fashion.
Although a pilot chute with more moderate drag will produce more consistent openings, a pilot chute can have too little drag....


http://www.skydivingmagazine.com/ques26.htm#How%20tight%20should%20my%20closing%20pin%20be%20secured?

And lastly:
Here are my rough calculations on relative surface area of common PC sizes. I don't know exactly how this correlates with the amount of drag generated.
Anyone have solid info? Also, could someone that's done math in the last decade verify my numbers?Wink

PC -- Surface area
20" = 314
22" = 380
24" = 452
28" = 615

Therefore, a 28" PC has about 36% more surface area than a 24"
The difference between a 20" and a 28" is about 96% more surface area for the 28"! I'd guess that the 20" is too small for most applications.

Thus, if you are having hard openings and jumping a 28" PC, you might want to consider going down a size or two and see if that helps.
-Josh


Hooknswoop  (D License)

Dec 21, 2003, 5:34 PM
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Re: [3ringheathen] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

I have a couple of questions:

1) If loose line stows cause hard openings and tight line stows cause soft openings, explain why main d-bags that use a pouch for the lines and only have locking stows do not cause hard openings?

2) If the size of the PC is so important, then why does a Javelin RS (PD-106R) and a Javelin J8 (PD-281R) have the same size reserve pilot chute. Why does the MZS (PD-106R) and M7 (PD-281R) have the same size reserve PC? If the size of the PC in relation to the canopy is so important, why the same size PC for the smallest to the largest reserve containers (within a model container)?

3) For a 150-ish canopy, the “A” lines are roughly 10-feet long. How much can the bag be de-accelerated in 10 feet?

4) If a smaller PC makes a canopy open softer, why did my 60 open the same with a 20-inch PC and a 24-inch PC?

From Poynter’s:

(In a wind tunnel at 120 mph)

A 40” PC was measure to have 131 pounds of drag
A 36” PC was measure to have 134.5 pounds of drag
A MA-1 (36”) was measured to have 139 pounds of drag
A 30” PC (Grabber) was measured to have 121.5 pounds of drag
A 42” PC (Grabber) was measured to have 274.5 pounds of drag

The single-PC measurements varied from 106.5 pounds to 274.5 pounds and from 30” to 42”.

What I have found to that affects how a canopy opens:

1) The design of the canopy. Some canopies inherently open soft and some inherently open hard.

2) Slider placement. It is critical that the slider be placed and kept against the slider stops while packing.

3) Deployment speed.

3) An even body position for deployment.

Derek


3ringheathen  (D 18302)

Dec 21, 2003, 7:23 PM
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Re: [Hooknswoop] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Quote:
In reply to:
I have a couple of questions:

1) If loose line stows cause hard openings and tight line stows cause soft openings, explain why main d-bags that use a pouch for the lines and only have locking stows do not cause hard openings?

Somtimes they do. Sometimes they don't. Line stows are but one of many factors that effect openings.
One can have high blood pressure without experiencing any cardiac problems, but it doesn't follow that high blood pressure is not a significant factor in heart disease.

Quote:
2) If the size of the PC is so important, then why does a Javelin RS (PD-106R) and a Javelin J8 (PD-281R) have the same size reserve pilot chute. Why does the MZS (PD-106R) and M7 (PD-281R) have the same size reserve PC? If the size of the PC in relation to the canopy is so important, why the same size PC for the smallest to the largest reserve containers (within a model container)?

Perhaps an industry insider can shed some light on the TSO process as it relates to this question.
I suspect that the gear is tested and approved with a specific configuration. I wonder if it varies for different size containers? In the old days, there wasn't all that much variability in parachute sizes. Perhaps the TSO rules haven't changed to reflect the wider spectrum of canopy sizes now available?
Of course the above is purely speculation on my part.

What I'm more certain of is that reserves and mains, particularly high performance mains are entirely different animals.

With a reserve, you generally want it to open as fast as possible without suffering personal injury or equipment damage. Reserves are almost exclusively seven cell parachutes with relatively conservative flight characteristics and are usually F-111 material.
Thus a reserve isn't likely to be as sensitive to pilot chute size in the first place, and the idea is to get an open parachute in a hurry. You absolutely can't risk a PC in tow with a reserve.

However, with a high performance main, soft openings are generally desirable and the wing form that gives the extraordinary flight characteristics both tend to require a bit more specialized a deployment system.
Put another way, a reserve will probably work just fine with a significantly smaller pilot chute, but if you want to experiment with it, you're probably violating a law or two, and you better pull a little higher.Angelic

Quote:
3) For a 150-ish canopy, the “A” lines are roughly 10-feet long. How much can the bag be de-accelerated in 10 feet?

That is a question better addressed to Performance Designs or one of the other key players in the industry. I don't claim to know all the answers.

Quote:
4) If a smaller PC makes a canopy open softer, why did my 60 open the same with a 20-inch PC and a 24-inch PC?

Just like the line stows, PC size is but one of many variables.
Why don't you throw my 38 on your canopy and see how that works?

Quote:
What I have found to that affects how a canopy opens:

1) The design of the canopy. Some canopies inherently open soft and some inherently open hard.

2) Slider placement. It is critical that the slider be placed and kept against the slider stops while packing.

3) Deployment speed.

3) An even body position for deployment.

Derek

Yes, those are all factors, too.
So are deployment altitude MSL, temperature, and humidity to name a few.
-Josh


Hooknswoop  (D License)

Dec 21, 2003, 7:51 PM
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Re: [3ringheathen] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Quote:
1) If loose line stows cause hard openings and tight line stows cause soft openings, explain why main d-bags that use a pouch for the lines and only have locking stows do not cause hard openings?

Somtimes they do. Sometimes they don't. Line stows are but one of many factors that effect openings.

They do? That is not what I have been hearing about the rubber-band-less D-bags being developed.

Quote:
In the old days, there wasn't all that much variability in parachute sizes. Perhaps the TSO rules haven't changed to reflect the wider spectrum of canopy sizes now available?

AS8015b was updated as of 7 July, 1992. There was a wide variety of reserve canopies available in 1992, but smaller containers do not have smaller PCs and larger containers do not have larger PC’s.

Quote:
What I'm more certain of is that reserves and mains, particularly high performance mains are entirely different animals.

With a reserve, you generally want it to open as fast as possible without suffering personal injury or equipment damage. Reserves are almost exclusively seven cell parachutes with relatively conservative flight characteristics and are usually F-111 material.
Thus a reserve isn't likely to be as sensitive to pilot chute size in the first place, and the idea is to get an open parachute in a hurry. You absolutely can't risk a PC in tow with a reserve.

So how hard a reserve canopy opens is not affected by PC size, but a main canopy is? I’m confused. Why the difference? Are you saying a Stiletto 107 would open hard with too large of a PC, but a PD-106R wouldn’t? Why?

Quote:
However, with a high performance main, soft openings are generally desirable and the wing form that gives the extraordinary flight characteristics both tend to require a bit more specialized a deployment system.

I have not found that to be the case with very high performance canopies (FX-79, FX-70, Stiletto 97, VX-60, Alpha 94, etc)

Quote:
Put another way, a reserve will probably work just fine with a significantly smaller pilot chute, but if you want to experiment with it, you're probably violating a law or two, and you better pull a little higher.

Actually, it is up to the assembling rigger to determine compatibility of TSO’d components. So as long as the smaller PC was TSO’d and the system still worked, the rigger could install it. [NOT RECOMMENDED, but legal]

Quote:
Just like the line stows, PC size is but one of many variables.
Why don't you throw my 38 on your canopy and see how that works?

If you can get it to me before the Eloy X-mas boogie, sure. Is it a kill-line PC? I’ll be jumping a Crossfire 104. I don’t want to put a 38-inch non-kill line PC on a Crossfire 104. If you can’t get it to me by then, don’t bother since I won’t be jumping after Eloy.

Sorry, not convinced, I don’t believe PC’s affect how hard a canopy opens.

If a manufacturer recommended that I use a 20-inch PC, it wouldn’t open my container. If they told me I needed that size PC in order for my canopy to open softly and anything larger will cause hard openings, I would buy a different canopy.

Derek


mjosparky  (D 5476)

Dec 21, 2003, 8:20 PM
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Re: [3ringheathen] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

I have been jumping a main D-bag with just 2 locking stows and the rest of the lines in a pouch for several years. I find there is no difference in the opening when using this bag or a bag with all lines stowed. A PC may affect the snatch force to some degree but will have no effect on the opening shock. As the canopy starts to open the PC stops functioning completely.


(This post was edited by mjosparky on Dec 21, 2003, 8:32 PM)


3ringheathen  (D 18302)

Dec 21, 2003, 8:39 PM
Post #6 of 40 (2442 views)
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Re: [Hooknswoop] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

In reply to:
Quote:
1) If loose line stows cause hard openings and tight line stows cause soft openings, explain why main d-bags that use a pouch for the lines and only have locking stows do not cause hard openings?

Somtimes they do. Sometimes they don't. Line stows are but one of many factors that effect openings.
Quote:
They do? That is not what I have been hearing about the rubber-band-less D-bags being developed.

I'm not familiar with rubber band less Dbags on skydiving mains. Since you say they are "being developed" I'd imagine that it's new technology. As such it doesn't prove or disprove anything relative to the designs that are currently common place.
Sticking with the automotive analogy, just because some newer cars don't have distributors, doesn't mean that those that rely on them aren't susceptible to problems from water in the distributor cap.
You can't compare apples and oranges.


Quote:
In the old days, there wasn't all that much variability in parachute sizes. Perhaps the TSO rules haven't changed to reflect the wider spectrum of canopy sizes now available?

Quote:
AS8015b was updated as of 7 July, 1992. There was a wide variety of reserve canopies available in 1992, but smaller containers do not have smaller PCs and larger containers do not have larger PC’s.

A wide variety? Not compared to what exists today.
Differing opinions on what constitutes a wide variety not withstanding, reserves are dramatically different in design and function than high performance mains.

Quote:
What I'm more certain of is that reserves and mains, particularly high performance mains are entirely different animals.

With a reserve, you generally want it to open as fast as possible without suffering personal injury or equipment damage. Reserves are almost exclusively seven cell parachutes with relatively conservative flight characteristics and are usually F-111 material.
Thus a reserve isn't likely to be as sensitive to pilot chute size in the first place, and the idea is to get an open parachute in a hurry. You absolutely can't risk a PC in tow with a reserve.
Quote:

So how hard a reserve canopy opens is not affected by PC size, but a main canopy is? I’m confused. Why the difference? Are you saying a Stiletto 107 would open hard with too large of a PC, but a PD-106R wouldn’t? Why?

Yes, you are confused. I didn't say that reserves aren't affected by PC size. I said that you want a reserve to open as fast as possible, so you naturally put a large pilot chute on it. With a reserve, the last thing you want is a nice, soft, slow opening.
It's far better to get slammed on a reserve deployment than to snivel into the ground.
I'm not saying that a PD 106R wouldn't open hard with a large reserve. I'm saying exactly the opposite.
It's just that when your reserve slams you, you're still grateful. When your main slams you, you spend the rest of the day bitching about it.Wink


Quote:
However, with a high performance main, soft openings are generally desirable and the wing form that gives the extraordinary flight characteristics both tend to require a bit more specialized a deployment system.

Quote:
I have not found that to be the case with very high performance canopies (FX-79, FX-70, Stiletto 97, VX-60, Alpha 94, etc)

Fair enough, but your anecdotal and limited experience pail in comparison to the rigorous experimentation that companies such as PD perform.
No insult intended, but a typical PD test pilot has far more jumps under far more strictly controlled circumstances than you and I combined are ever likely to accumulate, and they've reached different conclusions than you have. If you know anything about the scientific method, you know that anecdotal evidence doesn't mean all that much.


Quote:
Put another way, a reserve will probably work just fine with a significantly smaller pilot chute, but if you want to experiment with it, you're probably violating a law or two, and you better pull a little higher.


Quote:
Just like the line stows, PC size is but one of many variables.
Why don't you throw my 38 on your canopy and see how that works?

Quote:
If you can get it to me before the Eloy X-mas boogie, sure. Is it a kill-line PC? I’ll be jumping a Crossfire 104. I don’t want to put a 38-inch non-kill line PC on a Crossfire 104. If you can’t get it to me by then, don’t bother since I won’t be jumping after Eloy.

It's not collapsible. How about this:
Jump it while wearing a camera, take at least a 10 second delay, if it impairs the flight characteristics too much, chop it. I'll give you a $100 to cover the repack and excitement, but only if you still get a nice opening without packing it any differently than normal.


Quote:
Sorry, not convinced, I don’t believe PC’s affect how hard a canopy opens.

Don't be sorry. Some people don't believe we landed on the moon either.

Quote:
If a manufacturer recommended that I use a 20-inch PC, it wouldn’t open my container. If they told me I needed that size PC in order for my canopy to open softly and anything larger will cause hard openings, I would buy a different canopy.

Good plan, but no one is recomending a 20" pilot chute, so I'm not certain what your point is?
-Josh


3ringheathen  (D 18302)

Dec 21, 2003, 8:43 PM
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In reply to:
I have been jumping a main D-bag with just 2 locking stows and the rest of the lines in a pouch for several years. I find there is no difference in the opening when using this bag or a bag with all lines stowed. A PC may affect the snatch force to some degree but will have no effect on the opening shock. As the canopy starts to open the PC stops functioning completely.

According to your profile, you are jumping a Sharpchuter 245. Hardly a high performance canopy, and therefore, completely irrelevant to to my point.
-Josh


Premier PhreeZone  (D License)
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Dec 21, 2003, 8:52 PM
Post #8 of 40 (2429 views)
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How about my Jedei 136? that high proformance enough? I've got 200 jumps with no stows and 200 stowed on it and can't tell the difference. All open the same.

Here is a really cool thing to do to prove how little rubber bands and pilot chute size effect a canopy. Have a friend fly outside video about 10-15 feet above and beside you. Have the opening of a few pack jobs filmed. The main thing you want to have filmed is the difference between the pin being pulled and the slider being exposed to the airstream. Thats the only things that rubber bands or Pilot chute size can affect. The results will be the same for stowed or stowless. Pilot chute size matters so little that its only a frame or two (1/30 of a second) difference between all but the extreme sizes.

Bill Booth can answer this question better then anyone seeing as he practially invented the hand deploy PC Wink


Hooknswoop  (D License)

Dec 21, 2003, 9:30 PM
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Quote:
I'm not familiar with rubber band less Dbags on skydiving mains. Since you say they are "being developed" I'd imagine that it's new technology. As such it doesn't prove or disprove anything relative to the designs that are currently common place.

Basically they use a pouch for stowing the lines and a set of tabs to keep the bag shut until line stretch. No tight rubber bands to prevent hard openings. At least one 4-way team has put a lot of jumps on them. A search should bring up several threads on them.

Quote:
Sticking with the automotive analogy, just because some newer cars don't have distributors, doesn't mean that those that rely on them aren't susceptible to problems from water in the distributor cap.

Stiching with the automotive analogy? Who used an automotive analogy?

Quote:
You can't compare apples and oranges.

When did I compare apples to oranges? You said tight rubber bands help prevent hard openings. I countered that with the example of a d-bag that uses no rubber bands and only locking stows that is not producing hard openings to show that tight rubber bands are not necessary for soft openings.

Quote:
A wide variety? Not compared to what exists today.

Really, how many sizes of reserves have become available since 1992? A couple of smaller sizes and a couple of larger sizes. PD added the 113 and 106 on the low end and the 281 on the high end, from 8 sizes to 11. Those 3 sizes passed the more stringent requirements of TSO C23D. If the reserve PC made that big of a difference, they would have either failed because the PC was too big, or not opened within the altitude specified because the reserve PC was too small. Since they received TSO certification, this wasn’t the case.

Quote:
Yes, you are confused. I didn't say that reserves aren't affected by PC size. I said that you want a reserve to open as fast as possible, so you naturally put a large pilot chute on it.

Yes, I was/am confused.

Quote:
I'm not saying that a PD 106R wouldn't open hard with a large reserve. I'm saying exactly the opposite.

Are you saying a PD-106R opens harder than a PD-281R deployed out of the same type of container because they both have the same size reserve PC?

Quote:
Fair enough, but your anecdotal and limited experience pail in comparison to the rigorous experimentation that companies such as PD perform.
No insult intended, but a typical PD test pilot has far more jumps under far more strictly controlled circumstances than you and I combined are ever likely to accumulate, and they've reached different conclusions than you have. If you know anything about the scientific method, you know that anecdotal evidence doesn't mean all that much.

True enough, but I do know the difference between a hard and soft opening. I have put over 500 jumps on a single canopy, 3 different times. How many test jumps does PD put on a single size/type canopy before releasing it? I also know that PD claims that Sabre’s don’t open hard. I have learned that manufacturers aren’t the end-all of gear information. If they were, we wouldn’t ever need SB’s and AD’s.

Quote:
It's not collapsible. How about this:
Jump it while wearing a camera, take at least a 10 second delay, if it impairs the flight characteristics too much, chop it. I'll give you a $100 to cover the repack and excitement, but only if you still get a nice opening without packing it any differently than normal.

Deal, except the reserve re-pack is only $35.00 (I’m the rigger)

Quote:
Don't be sorry. Some people don't believe we landed on the moon either.

I do believe we landed on the moon.

Quote:
Good plan, but no one is recomending a 20" pilot chute, so I'm not certain what your point is?

“anyway on cobalts our pc recommendations are as follows:

170: 24" jim caser zero-p collapsable pc
150: 22-24" """"""
135 and smaller: 22" """"""

currently we are testing 20" pc for use with our 65-85 but at present we still recommend the 22" as we have tested that size thoroughly.. “

You are right, no one is recommending a 20-inch PC. They are recommending a 22-inch PC and researching a 20-inch. A 22-inch PC will cause a PC in tow and/or a PC hesitation on some rigs.

Interesting reading

Xaos-27 78 with only locking stows

Derek


(This post was edited by Hooknswoop on Dec 21, 2003, 9:35 PM)


mjosparky  (D 5476)

Dec 21, 2003, 9:33 PM
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In reply to:
According to your profile, you are jumping a Sharpchuter 245. Hardly a high performance canopy, and therefore, completely irrelevant to to my point.
-Josh

I have spent over 20 years involved in the testing and development of parachutes and parachute systems. Is that relevant to understanding the function and relationship of the various component parts of a parachute system?


RTB  (D 582)

Dec 22, 2003, 4:31 AM
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In reply to:

2) If the size of the PC is so important, then why does a Javelin RS (PD-106R) and a Javelin J8 (PD-281R) have the same size reserve pilot chute. Why does the MZS (PD-106R) and M7 (PD-281R) have the same size reserve PC? If the size of the PC in relation to the canopy is so important, why the same size PC for the smallest to the largest reserve containers (within a model container)?

Derek

I think the answer to that is pretty simple: Cost.
Sure the same pilot will work but there is no logic in that they should necessarily be the same. If I could have a larger reserve PC for my tandem I would, and if sunpath made a smaller PC for the XRS they would be easier to pack nicely and would work just the same.
If the manufacturers had to TSO different reserve PC's the rigs would cost more, they wouldn't be less functional.

There is also a difference in how a main PC is made, a small PC made with large hole mesh and ZP top skin will normally be more effective than a slightly larger one made of small hole mesh and F-111.
So size is not everything Wink

//r


Premier ianmdrennan  (D 25821)
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Dec 22, 2003, 4:59 AM
Post #12 of 40 (2352 views)
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Quote:
They are recommending a 22-inch PC and researching a 20-inch. A 22-inch PC will cause a PC in tow and/or a PC hesitation on some rigs.

Yep - I ditched my 24" cause of sub terminal hesitations. Irritating and not something I wanted to deal with if I had to get out low. I went back to my 32" ZP (yes ZP!) pilot chute, and besides higher snatch force (or whatever you call that initial jerk) I've experienced NO difference in the opening speeds on a 96, 90 and 84 velo.

I'm with you on this one, PC's (collapsable) don't effect opening speed in my experiences.

Blue skies
Ian


Hooknswoop  (D License)

Dec 22, 2003, 5:12 AM
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Quote:
I think the answer to that is pretty simple: Cost.

Right, my point is that the larger PC in relation to the resize on the low end does not cause hard openings.

Derek


riggerrob  (D 14840)

Dec 22, 2003, 5:56 AM
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In reply to:
I have a couple of questions:

1) If loose line stows cause hard openings and tight line stows cause soft openings, explain why main d-bags that use a pouch for the lines and only have locking stows do not cause hard openings?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Because the last few (2 to 4) locking stows are by far the most important. The key is keeping the slider at the top of the lines until line stretch, after that, any minor deceleration by rubber bands is, well, minor.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

2) If the size of the PC is so important, then why does a Javelin RS (PD-106R) and a Javelin J8 (PD-281R) have the same size reserve pilot chute. Why does the MZS (PD-106R) and M7 (PD-281R) have the same size reserve PC? If the size of the PC in relation to the canopy is so important, why the same size PC for the smallest to the largest reserve containers (within a model container)?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Cost!
Since spring-loaded reserve pilotchutes are expensive to test, manufacture and stock, most manufaturers only use one size. As a side note, only one manufacturer (Jump Shack) has offered more than one size of pilotchute and they are not selling huge numbers of Racers lately.

Secondly, freebags are far more forgiving of mis-matched pilotchute sizes. Since the freebag separates after line stretch, the pilotchute never gives that extra "jerk" at line stretch.

Finally, everyone expects reserve to open hard.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


4) If a smaller PC makes a canopy open softer, why did my 60 open the same with a 20-inch PC and a 24-inch PC?

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Because your 20-inch and 24-inch are near the same end of the range of possibilities (20 to 50 inch).

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

From Poynter’s:

(In a wind tunnel at 120 mph)

A 40” PC was measure to have 131 pounds of drag
A 36” PC was measure to have 134.5 pounds of drag
A MA-1 (36”) was measured to have 139 pounds of drag
A 30” PC (Grabber) was measured to have 121.5 pounds of drag
A 42” PC (Grabber) was measured to have 274.5 pounds of drag

The single-PC measurements varied from 106.5 pounds to 274.5 pounds and from 30” to 42”.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Those were four vastly different pilotchutes, with different fabrics, canopy shapes, spring shapes, etc.

In the end, sloppy packing can negate most of the decisions made by designers.

If I may introduce some anecdotal information: Last year I acquired an Ariel 150 for CHEAP because the owner never figured out how to pack for soft openings. I - on the other hand - have never had a hard opening with this canopy and my only firm opening was the result of a sloppy pack job.

In the end, neat packing is still more important than component selection.


TALONSKY  (D License)

Dec 22, 2003, 8:41 AM
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Maybe I am missing something but why is it only Atair request using smaller than standard pilot chutes. I mean I do not see PD, Icarus, or PA requesting their customers to modify stock rigs. Farther more, if pilot chutes do have a big affect on deployment why did Atair not design their canopies to use industry standard pilot chutes to begin with.
Kirk


Ron

Dec 22, 2003, 9:03 AM
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In reply to:
Maybe I am missing something but why is it only Atair request using smaller than standard pilot chutes. I mean I do not see PD, Icarus, or PA requesting their customers to modify stock rigs. Farther more, if pilot chutes do have a big affect on deployment why did Atair not design their canopies to use industry standard pilot chutes to begin with.

Because it was a design problem, and a smaller PC is a bandaid to fix it. Just like bigger or pocket sliders are bandaids to fix a design or construction problem

Be very leary of any company that makes you change a part of your system to make up for a bad design in in their part of the system.


TALONSKY  (D License)

Dec 22, 2003, 9:20 AM
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Re: [Ron] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Because it was a design problem, and a smaller PC is a bandaid to fix it. Just like bigger or pocket sliders are bandaids to fix a design or construction problem

Be very leary of any company that makes you change a part of your system to make up for a bad design in in their part of the system.
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That was kind of the point I was getting to. Supporters of Atair keep going on about pilot chute size, body position when pulling, and packing, but I believe if the canopy is designed well then it should open good without extra attention to anything. I find it rather interesting that Atair pushs all these issues yet refuses to acknowledge any design problems with their canopy.
Kirk


cloud9  (D 27635)

Dec 22, 2003, 9:46 AM
Post #18 of 40 (2268 views)
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Re: [TALONSKY] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

I'm not a so-called Atair supporter, but I do get tired of the bashing I see here. First off did smaller pilot chutes come to the market after Atair started making canopies? Hint answer no! so they do make their canopies to fit industry standards on pilot chutes. Next my wings came with a 24" ZP pilot chute the same size and type Atair recommends.
Finally PD one of the best companies out there made the Sabre, which is one of the hardest opening canopies ever, built. They even wrote an article on how to tame a hard opening canopy.
I have yet to hear them say there was a design flaw. I have heard it said get a pocket slider, or roll the nose, roll the nose and tuck it in the center cell and a bunch of other cures.
Icarus built the crossfire which was prone to collapse they have yet to admit to a design flaw, although they made a new Crossfire2.
I'm not bashing anyone just simple honest observations so what about the rest of you, honesty goes a long way!

I do not jump a Cobalt, I do jump a Space and it always opens very soft.


rigging65  (D 21921)

Dec 22, 2003, 9:50 AM
Post #19 of 40 (2267 views)
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Re: [3ringheathen] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

PD certainly has one of the finest test programs in the world, and they are, without a doubt, industry leaders. I'm constantly amazed by the stuff they do. With that said though, it doesn't mean they can't be wrong...

...and it seems like their (PD's) argument is the only thing anyone is hanging their hat on here when arguing against this. They're good, but they're not Gods. Yes, they are very good at what they do. Yes, they are very thorough...but so is NASA, and they've been wrong before too.

All I'm saying is it's totally possible that the process they use to test, given procedures, whatever, might not allow them to collect some data that is collected in the field, out of the controlled environment. I think it's fair to say that anyone would be remiss not to admit that it's possible that there is another way to skin this cat. And, if you admit that, then you have to admit that PD might not be perfectly on target with this...


Hooknswoop  (D License)

Dec 22, 2003, 9:57 AM
Post #20 of 40 (2263 views)
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Re: [cloud9] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Quote:
I'm not a so-called Atair supporter, but I do get tired of the bashing I see here.

Quote:
Finally PD one of the best companies out there made the Sabre, which is one of the hardest opening canopies ever, built. They even wrote an article on how to tame a hard opening canopy.
I have yet to hear them say there was a design flaw. I have heard it said get a pocket slider, or roll the nose, roll the nose and tuck it in the center cell and a bunch of other cures.

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Icarus built the crossfire which was prone to collapse they have yet to admit to a design flaw, although they made a new Crossfire2.

So, do you consider the above "bashing?"

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I'm not bashing anyone just simple honest observations so what about the rest of you, honesty goes a long way!

Guess not. So how is being honest about Cobalts "bashing"?

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First off did smaller pilot chutes come to the market after Atair started making canopies? Hint answer no! so they do make their canopies to fit industry standards on pilot chutes. Next my wings came with a 24" ZP pilot chute the same size and type Atair recommends.

They also recommend 22-inch PC's for smaller than 135 sq. ft., which is not industry standard................

BTW- I agree that Sabres open hard (or can) and that PD has not and probably never will admit it.

I disagree that the Crossfire1 had a design flaw, there was some manufacturing issues. I measured and inspected a Crossfire that was affected by the SB and found gross errors in the manufacturing of it. I will be jumping a different Crossfire made to the same specs, that was manufacturered correctly at Eloy. It flys (and opens) great.

Derek


cloud9  (D 27635)

Dec 22, 2003, 11:05 AM
Post #21 of 40 (2247 views)
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Re: [Hooknswoop] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Giving an honest opinion about a cobalt is not bashing. However making statements like you don’t see PD, or Icarus or whatever making such recommendations is, when they in fact have had some problems. PD, Icarus, Precision, Glide path and I’m sure several others have had problems with canopies of one type or another. All have made out of the norm recommendations to fix those problems.
Or to say Atair has a design problem because some Cobalt’s open hard, but that Icarus does not have a design problem when some Crossfire’s collapsed is also very biased. If some work great and others don’t its probably not a design flaw is it? It sounds more like quality control and all the manufactures have had some problems. To continually seek out one is again very biased.
Many very experienced jumpers (Chuck Blue) is one that comes to mind have said they have never had a bad Cobalt. On the other hand many other experienced jumpers say they have had nothing but bad experiences with their Cobalt’s. (Ron comes to mind) Those are honest opinions, to attack Atair because a Cobalt opens hard is bashing, unless the other manufactures are brought into the equation also; unless the conversation is just about Cobalts.
Think about this statement. “Be very leery of any company that makes you change a part of your system to make up for a bad design in their part of the system” this was directed at Atair. Now also consider that PD recommended some off hand packing technique’s people used pocket sliders etc. Icarus recalled canopies for a line trim mod and most people didn’t think the new Crossfire flew or opened a good as the pre-mod. Precision modified their reserve because some Ravens blew up; some PISA hornets went to larger sliders. Triathlons now have a modified or different break system. The Safire had a line mod in Fact Derek was a major part of that.
So what company is left? Is there still a canopy manufacturer out there that we can buy from with the above statement in mind?

I have nothing but respect for the jumpers with more experience then I have, and many here know more right now then I ever will. But I do know there seems to be a serious bias by some people towards Atair products and it’s even apparent that it comes from a dislike or distrust of Dan Preston. All I’m asking is that you very experienced, knowledgeable people keep us informed (because we do appreciate it) without biased statements and with facts or personal knowledge.


Hooknswoop  (D License)

Dec 22, 2003, 11:24 AM
Post #22 of 40 (2240 views)
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Re: [cloud9] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Quote:
Giving an honest opinion about a cobalt is not bashing. However making statements like you don’t see PD, or Icarus or whatever making such recommendations is, when they in fact have had some problems.

I don't see PD, Icarus or whatever recommending smaller PC's to fix a hard opening canopy.

Quote:
PD, Icarus, Precision, Glide path and I’m sure several others have had problems with canopies of one type or another. All have made out of the norm recommendations to fix those problems.

What out of norm recommendations had PD made, or Icarus or Flight Concepts?

Quote:
Or to say Atair has a design problem because some Cobalt’s open hard

I don't know if it a design or QC problem with Cobalts, but they do have a reputation for opening hard. A smaller PC for the fix is silly. I do remember reading somewhere that they were re-designing the Cobalt 170 because of opening issues.

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but that Icarus does not have a design problem when some Crossfire’s collapsed is also very biased.

I don't think the Crossfire1 was a design flaw, but a QC problem.

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If some work great and others don’t its probably not a design flaw is it? It sounds more like quality control and all the manufactures have had some problems. To continually seek out one is again very biased.

This thread was started in response to the PCsize/Cobalt thread.

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Many very experienced jumpers (Chuck Blue) is one that comes to mind have said they have never had a bad Cobalt.

I had an Alpha 94 that opened great.

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On the other hand many other experienced jumpers say they have had nothing but bad experiences with their Cobalt’s. (Ron comes to mind)

People say the same things about Sabres, some open hard, some open great.

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Those are honest opinions, to attack Atair because a Cobalt opens hard is bashing, unless the other manufactures are brought into the equation also; unless the conversation is just about Cobalts.

OK, some Sabres, and some Cobalts open hard. A few Crossfires that weren't manufactured correctly had collapsing issues. I fail to see how it is bashing to say some Sabres open hard if you don't also mention another canopy twith the same issues.

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Think about this statement. “Be very leery of any company that makes you change a part of your system to make up for a bad design in their part of the system” this was directed at Atair.

You read it that way. PM the poster and find out if that was their intention.

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Now also consider that PD recommended some off hand packing technique’s people used pocket sliders etc.

Off hand packing techniques? I do know they do not recommend pocket sliders, I asked.

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Icarus recalled canopies for a line trim mod and most people didn’t think the new Crossfire flew or opened a good as the pre-mod.

True. The difference is they admitted to the problem and fixed it at their cost.

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Precision modified their reserve because some Ravens blew up;some PISA hornets went to larger sliders. Triathlons now have a modified or different break system. The Safire had a line mod in Fact Derek was a major part of that.

True, but this changes nothing about the Cobalt, nor their advertising of how they open.

Quote:
So what company is left? Is there still a canopy manufacturer out there that we can buy from with the above statement in mind?

I know of no other manufacturer that recommends a smaller PC or other mod to fix a hard opening canopy. I have seen manufacturers take back and either fix at their cost or replace hard opening canopies.

Quote:
I have nothing but respect for the jumpers with more experience then I have, and many here know more right now then I ever will. But I do know there seems to be a serious bias by some people towards Atair products and it’s even apparent that it comes from a dislike or distrust of Dan Preston. All I’m asking is that you very experienced, knowledgeable people keep us informed (because we do appreciate it) without biased statements and with facts or personal knowledge.

I call it like I see it. I do think that claims that are obviously not true by a manufacturer can lead to their being hammered for it here in the forums. Recommending a smaller (or possibly too-small PC) to fix a canopy that is opening too hard qualifies.

Edit: If PD or Icarus recommends to someone to put a 22-inch PC on their rig to cure a hard opening canopy, I would rake them through the coals too.

Derek


(This post was edited by Hooknswoop on Dec 22, 2003, 11:44 AM)


TALONSKY  (D License)

Dec 22, 2003, 12:02 PM
Post #23 of 40 (2227 views)
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Re: [cloud9] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

May be I missstated what I was trying to get across earlier. I was stating in relationship to pilot chute size ONLY, that I do no recall any other manufacturer out there requesting a smaller than stock Pilot chute size in order to get good openings ( now by smaller than stock, I mean I have had 4 rigs and ordered 2 pilot chutes and all of them are 28”, I am sure you could order from some factories smaller ones but on an average I would bet that 28” is pretty standard and 22” to 24” are very rare). Also by no means in my statement was I even implying that no other canopy manufacture has made mistakes in the past or present I only was relating things as far as pilot chute size (which if I am not mistaken is what this original post was about to begin with)
Kirk


DBCOOPER  (D 24112)

Dec 22, 2003, 12:27 PM
Post #24 of 40 (2219 views)
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Re: [Hooknswoop] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

Quote:
I know of no other manufacturer that recommends a smaller PC or other mod to fix a hard opening canopy
I know of no other manufacturer that recommends you dump in a track either.


cloud9  (D 27635)

Dec 22, 2003, 1:57 PM
Post #25 of 40 (2199 views)
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Re: [DBCOOPER] Industry info relevant to PCsize/opening thread [In reply to] Can't Post

The 24" pilot chute that came with my wings was not special ordered. I ordered the container for a Heatwave 150 main and that's the pilot chute that came with it.
As far a dumping in a track maybe no one else does recomend it, Idon't know but I do know that they should know how to deploy the canopy they designed. I also know that George Galloway was recomending Pyscho packing for a long time and many other manufacturers still recomend you don't. Does that make George stupid or wrong? I don't think so.


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