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albntomat0

Reserves Smaller than Main

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Danh124

There are also a few different ways of measuring canopy size which makes this more confusing. For example I am lead to believe PDR 176 is actually more like a 190. I jump a Safire 2 189 with a 176 and have been assured it's actually pretty much the same size. As a low time jumper I hope this is true.
Definitely a confusing subject for us newbies.



I hate it when so-called experienced jumpers trot out that BS argument, about PD canopies 'actually being more like a size larger'. :S
By the same reasoning you could say that Icarus/Aerodyne/etc. is 'more like a size smaller'.

[rant] Next time anyone tells you something like that, just smile and nod politely and go to someone qualified, like a rigger (which I'm not).

Yes, there are different ways of measuring canopies. but unless you're a particularly high-talented competition swooper, you should view a 189 as a 189 and a 176 as a 176.

Differences in size become more pronounced as the canopies get smaller. For instance, the flight characteristics between a 97 and a 120 of the same type are much different than between a 240 and a 190 of that same type.

Aside from that, there should be no problem with a 176 as a reserve vs a 189 main. Though it is not all about size; the main is designed to have fun with, the reserve to get you home safely.
[/rant]
"That formation-stuff in freefall is just fun and games but with an open parachute it's starting to sound like, you know, an extreme sport."
~mom

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Baksteen

***There are also a few different ways of measuring canopy size which makes this more confusing. For example I am lead to believe PDR 176 is actually more like a 190. I jump a Safire 2 189 with a 176 and have been assured it's actually pretty much the same size. As a low time jumper I hope this is true.
Definitely a confusing subject for us newbies.



I hate it when so-called experienced jumpers trot out that BS argument, about PD canopies 'actually being more like a size larger'. :S
By the same reasoning you could say that Icarus/Aerodyne/etc. is 'more like a size smaller'.

[rant] Next time anyone tells you something like that, just smile and nod politely and go to someone qualified, like a rigger (which I'm not).

Yes, there are different ways of measuring canopies. but unless you're a particularly high-talented competition swooper, you should view a 189 as a 189 and a 176 as a 176.

Differences in size become more pronounced as the canopies get smaller. For instance, the flight characteristics between a 97 and a 120 of the same type are much different than between a 240 and a 190 of that same type.

Aside from that, there should be no problem with a 176 as a reserve vs a 189 main. Though it is not all about size; the main is designed to have fun with, the reserve to get you home safely.
[/rant]

Agreed across the board, but I jump a smaller main than reserve unless the main is huge as well.

I have landed reserves including 26' conical and 177 sf 5 cell (Swift), and have concluded that sizing the reserve is a matter of what I want over me if I'm incapacitated.

Having your collarbone broken on exit can make using toggles effectively impossible, so you may want to keep your brakes stowed and steer by shifting in the saddle.

Being unconscious for any reason - medical, injury, etc. - makes steering a non-issue.

Having had an elbow to the nose in freefall that made seeing through all the blood problematic, it turns out that there are rather a few things that can make seeing where you are going difficult or impossible. You don't want to be under a reserve where being able to see clearly is necessary to avoid getting hurt.

Regardless of what you jump as a main, a reserve is a whole different ball game, and should be treated as such. It's hard to look stylish in a trauma center.


BSBD,

Winsor

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I just ordered my first rig and the reserve is smaller than the main because of the combination I am going with for the ability to downsize. I have a pulse 190 main and a 160 reserve. The pulse 190 packs low volume so I was able to go with a smaller container that will allow me to downsize to 150.

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Agreed!
That debating point made sense back in 1980, but is irrelevant for canopies designed during this century.

Back in 1980, a half dozen different manufacturers used a half dozen different canopy measuring methods. Eventually, PIA published Para-Flite's method and it was fashionable for a couple of decades. Para-Flite measured chord from the tail to the top leading edge, easy on rectangular canopies.

That became problematic when tapered ( elliptical, swept-wing, Schuemann, etc.) canopies became fashionable during the 1990s. By 2001, most major manufacturers had adopted Performance Designs' method of measuring chord along the bottom skin. Now that most manufacturers use the PD methods, comparisons are simpler.

Please do not use mere numbers to compare (early 1980s-vintage) Ravens (Swifts, Firelites, APS, etc.) reserves with modern Optimum, Smart, etc. reserves because they are in totally different generations.

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>I hate it when so-called experienced jumpers trot out that BS argument, about PD
>canopies 'actually being more like a size larger'

Uh . . . OK. So don't listen when people discuss such things.

When Icarus first came out with the Safire line, the Safire 1's were sized a size smaller than any other Icarus canopies - including (later) the Safire 2. Knowing that a Safire 1 129 was really the equivalent of a 119 was important for newer jumpers who didn't want to downsize too quickly.

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billvon

>I hate it when so-called experienced jumpers trot out that BS argument, about PD
>canopies 'actually being more like a size larger'

Uh . . . OK. So don't listen when people discuss such things.

When Icarus first came out with the Safire line, the Safire 1's were sized a size smaller than any other Icarus canopies - including (later) the Safire 2. Knowing that a Safire 1 129 was really the equivalent of a 119 was important for newer jumpers who didn't want to downsize too quickly.



Precision used to measure canopies differently allegedly so they could claim the smallest pack volume in the industry.
Chuck Akers
D-10855
Houston, TX

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Something I've been curious about. I see a lot of jumpers say that the weight to size ratio scales down. Well, they don't say it that way but what I mean for instance is this. First off, assume all other things are equal, type of canopy, all that. Does a 100 pound person jumping a 100 square feet canopy get the same performance as a 170 pound person jumping a 170? It seems to me that the 100 to 100 combination would be a lot hotter since there are other things involved. Anyone know what the results really are?

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>Does a 100 pound person jumping a 100 square feet canopy get the same
>performance as a 170 pound person jumping a 170?

Absolutely not. Almost nothing in canopies scales that way.

John LeBlanc did a seminar years ago at PIA about how to scale canopies. He made half a dozen statements - "to get the same turn rate, make sure the loading is about the same as jumper weight decreases." "Loading determines risk on landing, rather than canopy size." At the end of all those "common sense" statements (to which about half the audience was nodding) he said "none of those statements are true."

There are so many different things that affect performance, from the line width to chord ratio to the pendulum distance to the overall size of the canopy, that you cannot safely make any assumptions like the ones above. The exact same make of canopy, at exactly the same loading, will fly completely differently over a 120 lb woman as over a 210lb guy.

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billvon

>I hate it when so-called experienced jumpers trot out that BS argument, about PD
>canopies 'actually being more like a size larger'

Uh . . . OK. So don't listen when people discuss such things.



I don't have that luxury if they are talking to inexperienced jumpers or students, now do I? [:/]

That being said, I haven't heard it anymore for at least the past year and a half.
"That formation-stuff in freefall is just fun and games but with an open parachute it's starting to sound like, you know, an extreme sport."
~mom

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Baksteen



I hate it when so-called experienced jumpers trot out that BS argument, about PD canopies 'actually being more like a size larger'. :S
By the same reasoning you could say that Icarus/Aerodyne/etc. is 'more like a size smaller'.

[rant] Next time anyone tells you something like that, just smile and nod politely and go to someone qualified, like a rigger (which I'm not).

Yes, there are different ways of measuring canopies. but unless you're a particularly high-talented competition swooper, you should view a 189 as a 189 and a 176 as a 176.



Well, I have seen more than one person carted off because they didn't know something like that the 135 they were jumping was actually a 119.

So you can hate it all you want.... And you can claim I am not *experienced* if you like... But I have experienced watching some hot shot hammer in on a canopy they had no business jumping because well intended but clueless people told them the size they were jumping was "aggressive", but not insane.
"No free man shall ever be debarred the use of arms." -- Thomas Jefferson, Thomas Jefferson Papers, 334

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billvon

>Does a 100 pound person jumping a 100 square feet canopy get the same
>performance as a 170 pound person jumping a 170?

Absolutely not. Almost nothing in canopies scales that way.

John LeBlanc did a seminar years ago at PIA about how to scale canopies. He made half a dozen statements - "to get the same turn rate, make sure the loading is about the same as jumper weight decreases." "Loading determines risk on landing, rather than canopy size." At the end of all those "common sense" statements (to which about half the audience was nodding) he said "none of those statements are true."

There are so many different things that affect performance, from the line width to chord ratio to the pendulum distance to the overall size of the canopy, that you cannot safely make any assumptions like the ones above. The exact same make of canopy, at exactly the same loading, will fly completely differently over a 120 lb woman as over a 210lb guy.



I'd like to see that info get out to drop zones. Maybe Parachutist could run some articles on it.

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Ron

***

I hate it when so-called experienced jumpers trot out that BS argument, about PD canopies 'actually being more like a size larger'. :S
By the same reasoning you could say that Icarus/Aerodyne/etc. is 'more like a size smaller'.

[rant] Next time anyone tells you something like that, just smile and nod politely and go to someone qualified, like a rigger (which I'm not).

Yes, there are different ways of measuring canopies. but unless you're a particularly high-talented competition swooper, you should view a 189 as a 189 and a 176 as a 176.



Well, I have seen more than one person carted off because they didn't know something like that the 135 they were jumping was actually a 119.

So you can hate it all you want.... And you can claim I am not *experienced* if you like... But I have experienced watching some hot shot hammer in on a canopy they had no business jumping because well intended but clueless people told them the size they were jumping was "aggressive", but not insane.

Er.. that's exactly my point, Ron...:)
"That formation-stuff in freefall is just fun and games but with an open parachute it's starting to sound like, you know, an extreme sport."
~mom

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Honestly, I fail to wrap my head around even the concept of a <150 sqft reserve. I cannot think of any situation in which a very large reserve will kill you, and plenty of situations in which a very small reserve will kill you. The reserve parachute isn't for looking cool, it's for getting down alive.

Keep the homesick bowlingballs as main canopies please, but once you have to chop it (while already low, in a shit spot and filled with adrenaline up to your packing tabs), having a big floaty fluffy matrass is what I want above my head.

It's also part of the reason why I'm reluctant to work towards swooping as a discipline. With the kind of canopies I want to learn to fly, finding a rig that can securely hold that size main while having a size reserve I like is difficult to downright impossible. I'm not a light feather, so I'm talking a 190+ reserve at minimum. What's the smallest main you can fit in a rig made for a 190 reserve? I have yet to see anything smaller than ~160 for suitable use as a main canopy...

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I'm told Infinity will build pretty much anything you want. John Mitchell here on dz.com has a rig with a 150 main and a 200+ sq. ft. reserve built by them. And it looks perfectly reasonable. I think he used to have a 120 with a similar reserve.

Wendy P.
There is nothing more dangerous than breaking a basic safety rule and getting away with it. It removes fear of the consequences and builds false confidence. (tbrown)

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