Jan 18, 2003, 5:33 PM
Post #4 of 62
(2138 views)
Shortcut
Re: [JFC3] Type of main canopy you fly?
[In reply to]
Can't Post
Well, cobalt, samurai's etc are taped on trailing and leading edges. But then the stiletto is only tapred on the leading edge, and that's considered fully elip.
Jan 18, 2003, 7:22 PM
Post #5 of 62
(2103 views)
Shortcut
Re: [rmsmith] Type of main canopy you fly?
[In reply to]
Can't Post
I'm junking my Stiletto, and buying a new Hornet. I will then dedicate my jumps to the Hornet and the Xaos. It's the best 2 canopy combo I can think of.
Jan 18, 2003, 7:53 PM
Post #7 of 62
(2087 views)
Shortcut
Re: [JFC3] Type of main canopy you fly?
[In reply to]
Can't Post
Quote:
Now I may be wrong, but there are no "fully" eliptical canopies. They're all tapered to one degree or another.
This is something that the old-timers can speak to, but wasn't there a fully elliptical canopy a number of years ago? I seem to remember someone talking about a canopy that came to a point at both ends.
Jan 19, 2003, 10:07 PM
Post #8 of 62
(1913 views)
Shortcut
Re: [rmsmith] Type of main canopy you fly?
[In reply to]
Can't Post
I currently jump a Stiletto but will probably be looking to purchase a Crossfire2 or a Vengeance later this summer when I'm ready for my next downsize.
Jan 20, 2003, 6:42 PM
Post #15 of 62
(1631 views)
Shortcut
Re: [rmsmith] Type of main canopy you fly?
[In reply to]
Can't Post
i hate these type of threads.
the degree of taper is only 1 variable of many that determines if a canopy is a student canopy or pocket rocket.
there are beginner canopies with more taper than some extreme canopies !
thinking of the 'degree of ellipticalness' or terms like tapered, semi-tapered, or semi-elliptical is technically incorrect in this context and simply misleading. these terms are simply marketing jargon to describe performance at a given wing loading for a target consumer. all born by manufacturers catering to a general consumer ignorance.
put up a poll for canopy type and wingloading. it would be more informative.
sincerely,
dan<><>
ps. there is no such thing as fully elliptical in a skydiving wing.
Jan 20, 2003, 7:36 PM
Post #18 of 62
(1605 views)
Shortcut
Re: [PhreeZone] Type of main canopy you fly?
[In reply to]
Can't Post
Quote:
Im guessing Sabre2 has more taper then an FX.
more than likely, but i have never scene a sabre 2 up close, or flying in the air (at leas that i know of) and more than the vx, xaos's, and velocity's. and i can't speak for the onyx, or the crossbraced airlocked, but when i say the crossbraces airlocked, it looked a lot like the fx's, vx's, xaos's, and velocity's.
Jan 20, 2003, 7:47 PM
Post #19 of 62
(1599 views)
Shortcut
Re: [cobaltdan] Type of main canopy you fly?
[In reply to]
Can't Post
Quote:
thinking of the 'degree of ellipticalness' or terms like tapered, semi-tapered, or semi-elliptical is technically incorrect in this context and simply misleading. these terms are simply marketing jargon to describe performance at a given wing loading for a target consumer. all born by manufacturers catering to a general consumer ignorance.
Plan-form shape is one consideration of a canopies performance. The terms square, semi-elliptical (really tapered on the trailing edge), and elliptical (really tapered on the leading and trailing edges) allow skydivers to break canopies down into three categories of performance. True, there are beginner-class canopies w/ more taper than some high performance canopies, but there aren't any elliptical beginner-class canopies, nor are there any beginner-class canopies that out-perform the high performance elliptical canopies. Generally as the canopy plan-form goes from square to semi-elliptical, to fully elliptical (marketing terms, but widely recognized) the turn rate and performance characteristics of the canopies increase. There are exceptions to every rule, but I can’t think of a single square canopy that will out-perform an elliptical canopy, all other things being equal (wing loading, size, pilot, material, etc).
Breaking down canopies into different classes by square, semi-elliptical, elliptical, and cross-braced doesn't seem like that bad of an idea, given the lack of an alternate idea and serves as a pretty good guide to a canopy's characteristics.
Jan 21, 2003, 6:54 AM
Post #20 of 62
(1552 views)
Shortcut
Re: [Hooknswoop] Type of main canopy you fly?
[In reply to]
Can't Post
hey hook,
"True, there are beginner-class canopies w/ more taper than some high performance canopies, but there aren't any elliptical beginner-class canopies,"
there are: i.e. alpha vs space: market conception is that the alpha is an fully elliptical swoop machine while the space is a semi-tapered begineers canopy. the two canopies are 100% identical they have the same planform(btw also identical planform to the cobalt and onyx). . so at light loadings if particular canopy design performs docile and is ideal for beginers it is called tapered or semi, at high wing loadings with more agressive performance it is called fully elliptical, even though it is the same planform.
i am trying to educate that planform does not dictate performance level. it is only 1 variable of many that determines the performance level of a canopy design.
so yes our student canopy is considerably more elliptical than many canopies you will see in swoop competitions.
breaking things down into these marketing terms is definately misleading and acceptance of such limits the amount of information available to the consumer from manufacturers. most manufactureres will simply tell you what you want to hear to make a purchase.
"Breaking down canopies into different classes by square, semi-elliptical, elliptical, and cross-braced doesn't seem like that bad of an idea, given the lack of an alternate idea and serves as a pretty good guide to a canopy's characteristics."
exactly my point in that it is not a pretty good guide. better is to simply view a chart of a canopy's perfromance vs wing loading.
when it comes to modern canopies you are no longer a parachutist, you are a pilot. i would like to see jumpers be far more educated about the wings they pilot.
Jan 21, 2003, 1:13 PM
Post #22 of 62
(1482 views)
Shortcut
Re: [cobaltdan] Type of main canopy you fly?
[In reply to]
Can't Post
Quote:
"True, there are beginner-class canopies w/ more taper than some high performance canopies, but there aren't any elliptical beginner-class canopies,"
there are: i.e. alpha vs space: market conception is that the alpha is an fully elliptical swoop machine while the space is a semi-tapered begineers canopy. the two canopies are 100% identical they have the same planform(btw also identical planform to the cobalt and onyx). . so at light loadings if particular canopy design performs docile and is ideal for beginers it is called tapered or semi, at high wing loadings with more agressive performance it is called fully elliptical, even though it is the same planform.
i am trying to educate that planform does not dictate performance level. it is only 1 variable of many that determines the performance level of a canopy design.
so yes our student canopy is considerably more elliptical than many canopies you will see in swoop competitions.
breaking things down into these marketing terms is definately misleading and acceptance of such limits the amount of information available to the consumer from manufacturers. most manufactureres will simply tell you what you want to hear to make a purchase.
"Breaking down canopies into different classes by square, semi-elliptical, elliptical, and cross-braced doesn't seem like that bad of an idea, given the lack of an alternate idea and serves as a pretty good guide to a canopy's characteristics."
exactly my point in that it is not a pretty good guide. better is to simply view a chart of a canopy's perfromance vs wing loading.
when it comes to modern canopies you are no longer a parachutist, you are a pilot. i would like to see jumpers be far more educated about the wings they pilot.
sincerely,
dan<><>
A few questions:
At what wing loading is a Cobalt "ideal" for beginners, and how many skydives (range) do you define "beginner" as?
Your student canopy, do you mean the Cobalt?
How do you define performance? Max speed? Max turn rate? Glide ratio? Altitude lost in a 360-degree turn?
Do you dis-agree that an elliptical (tapered) [even Atair uses the term elliptical, even though we all know canopies are really tapered, it is a term that is recognized by everyone and understood, like Zerox], canopy will have better performance than a square (rectangular) [another skydiving term, square canopies are really rectangular], all other things being equal?
Does Atair have a chart showing performance vs. wing loading for the Cobalt?
It seems to me a un-bias company would have to do the tests for each and every canopy, using expensive test equipment and a hundred jumps or so per canopy for each size, to get such a chart. Even then, without really nice test equipment, some of it might still be subjective. Sounds very expensive and time consuming. I don't see Performance vs. Wing loading charts in our future. So I guess we are stuck with dividing canopies into three categories, square, semi, and fully elliptical, then comparing them within those categories.
quade (D 22635)
Moderator
Jan 21, 2003, 1:32 PM
Post #23 of 62
(1471 views)
Shortcut
Re: [Hooknswoop] Type of main canopy you fly?
[In reply to]
Can't Post
Quote:
It seems to me a un-bias company would have to do the tests for each and every canopy, using expensive test equipment and a hundred jumps or so per canopy for each size, to get such a chart. Even then, without really nice test equipment, some of it might still be subjective.
It would be interesting to at least see some simple and useful information such as polar curves for the recommended weight range of the canopy. This -could- be done fairly inexpensively using nothing more than a Kestral 4000. Make one CRW altitude test jump at the lower, middle and upper recommended range for that particular canopy and I think you'd have all the data to generate the curves.
At least, that's how I'm planning on doing it. Of course, I'll only be doing it for my canopy at my wingloading so I think I'm only going to need to do one jump. We'll see how that works out in reality.
BTW, airplane companies are required to do this sort of testing for certification purposes. It's not all that difficult or expensive, nor does it need to be performed by an un-biased 3rd party as long as everyone involved is interested in facts and not marketing.
Jan 21, 2003, 1:43 PM
Post #24 of 62
(1467 views)
Shortcut
Re: [quade] Type of main canopy you fly?
[In reply to]
Can't Post
Quote:
BTW, airplane companies are required to do this sort of testing for certification purposes. It's not all that difficult or expensive, nor does it need to be performed by an un-biased 3rd party as long as everyone involved is interested in facts and not marketing.
Right, but aircraft are equipped with altimeters, VSI's, airspeed indicators,etc. Canopys aren't. Plus the test flight can last 3 hourse, generally. Canopy flights are not anywhere near that long. Didn't like that short field landing, power up and try again, no packing, manifesting, ride to altitude, etc. If was easy and cheap, and proved that a particular canopy's performance, manufacturers would publish these charts.
Think about how much it would cost to fully test one canopy, roll rate, descent rate, glide ratio, airspeed, etc, over a wide range of wing loadings. Then compensate for non-standard temperature and pressure. If it was cheap, why hasn;t it been done?
I have read a lot of ads proclaiming a canopy to have the "highest perfomance" of any canopy. Jumpers are interested in facts, manufacturers give us marketing.
45 /
18%
Of course, I'll only be doing it for my canopy at my wingloading so I think I'm only going to need to do one jump. We'll see how that works out in reality. 
1
