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QuoteGood luck on the choices you make, but remember 1.4 WL is a performance WLing- I want an Xfire2 in that department of 1.45 but i'm waiting still for a while because unfortunetly shit happens out there.
I'm actually going for a 1.3-1.35 WL and barring bad luck, I will be at 300+ jumps by the time I take delivery. But if Icarus has a 500 jump minimum, that's going to throw a wrench in things.
-Blind
"If you end up in an alligator's jaws, naked, you probably did something to deserve it."
jakee 1,584
QuoteI do accept that, that's why i am trying to minimize it. I'm not trying to match the performance of a smaller wing, i'm just trying to partially compensate for the longer lines and bigger wing.
I still don't understand why you think you will be less efficient than a similar wingloading an a smaller size. Look at pro-swooping, 111's are more efficient than Luigi's 39 in the same way that your 229 will be more efficient than a 119.
It won't handle the same way but wtf does that have to do with drag?
Do you want to have an ideagasm?
***I'm actually going for a 1.3-1.35 WL and barring bad luck, I will be at 300+ jumps by the time I take delivery***
This is another area where you may run into problems. Buying gear based on future weight loss and/or jump numbers almost never works out the way you plan. Just something to think about.
This is another area where you may run into problems. Buying gear based on future weight loss and/or jump numbers almost never works out the way you plan. Just something to think about.
frost 1
QuoteThe drag is already compensated for by the massive increase in drive (your weight). You would be more efficient under that hypothetical wing than someone on a 99 with the same loading.
Right?
Are you serious?
SoFPiDaRF - School of Fast Progress in Downsizing and Radical Flying. Because nobody knows your skills better than you.
frost 1
QuoteA customer walks in and asks for a 209 sf XFire 2.
Your mission, if you choose to accept it, is to compensate for the massive wing size by reducing drag in any practicle way.
To further test your skill, the client adds to requirements. 1. After any mods, the canopy must be capable of handling deployment speeds in the 160 mph range, 2. If you go with a custom lineset, it has to be able to handle a jumper with a 290 lb exit weight.
-Blind
Why? Why would you want to do that? Just curious about your motivation.
SoFPiDaRF - School of Fast Progress in Downsizing and Radical Flying. Because nobody knows your skills better than you.
frost 1
Quote
Look at pro-swooping, 111's are more efficient than Luigi's 39 in the same way that your 229 will be more efficient than a 119.
LOL I guess you WERE serious. You're wrong dude. Talk to people that know around your dropzone to find out why or ask here.
SoFPiDaRF - School of Fast Progress in Downsizing and Radical Flying. Because nobody knows your skills better than you.
jakee 1,584
QuoteLOL I guess you WERE serious. You're wrong dude. Talk to people that know around your dropzone to find out why or ask here.
Fair enough, so what am I missing?
Here is what I currently understand about different size canopies with the same loading:
Larger canopies are less responsive due to longer line sets and less deflection for a given length of toggle stroke;
Larger canopies are more efficient at keeping their speed during swoops because they have a smaller ratio of parasitic drag to lift induced drag. Proportionally speaking the lines, seams, d-bag, pilot etc are smaller when compared to the overall size of the canopy.
if thats wrong please tell me which bit I haven't understood, I like to learn
Do you want to have an ideagasm?
frost 1
if you want to learn, I'd highly recomment you read The Parachute and its Pilot by Brian Germain to learn from someone with undisputed knowledge of the subject.
http://www.bigairsportz.com/publishing.php
But to quickly answer why big wing loaded same as small wing will not be more efficent ... Basically it comes down to finding that sweet spot where the drag/lift ratio is kept at its optimal point. If you load it too much - you lose lift. If you get too big of a wing you get too much drag...
"111's are more efficient than Luigi's 39" not because they are bigger... he is loading that 39 at... well, i dont know exactly, probably 4 to 1? That is just NOT an efficent wing loading for that type of a canopy.
http://www.bigairsportz.com/publishing.php
But to quickly answer why big wing loaded same as small wing will not be more efficent ... Basically it comes down to finding that sweet spot where the drag/lift ratio is kept at its optimal point. If you load it too much - you lose lift. If you get too big of a wing you get too much drag...
"111's are more efficient than Luigi's 39" not because they are bigger... he is loading that 39 at... well, i dont know exactly, probably 4 to 1? That is just NOT an efficent wing loading for that type of a canopy.
SoFPiDaRF - School of Fast Progress in Downsizing and Radical Flying. Because nobody knows your skills better than you.
QuoteIf you load it too much - you lose lift. If you get too big of a wing you get too much drag...
You're making these statements as if loading too much is one thing, and the inverse is too big a wing, implying that the loading would be inadequate )as in under the 'sweet spot').
How does the 'sweet spot' translate to a bigger wing? Does the increased drag create the need for a higher loading to be 'swwet'?
Is the 'sweet spot' a function of loading, or size? Or does it change with each size? If so, what direction does the scale go; does a bigger wing need more or less loading? A smaller wing?
In the end, I think you may be wrong. If you can answer my queations, I may be wrong (but I'm not).
jakee 1,584
QuoteBut to quickly answer why big wing loaded same as small wing will not be more efficent ... Basically it comes down to finding that sweet spot where the drag/lift ratio is kept at its optimal point. If you load it too much - you lose lift. If you get too big of a wing you get too much drag...
That's the thing though, we are talking about identical loadings, the original poster is saying that his wing will be slow not because it is underloaded but simply because it is big.
I may have confused the issue by throwing in the 39, I just wanted an extreme example. You will agree though that a 111 or 120 will be slightly more efficient than a 79 with the same loading, and it is for this reason that the pro's use them now. Why should that trend stop when you get up to the sizes BlindBrick is talking about.
I still don't see why his 1.35 loaded 229 will be any less efficient than a 1.35 loaded 119.
Anyone?
Do you want to have an ideagasm?
piisfish 140
QuoteI still don't see why his 1.35 loaded 229 will be any less efficient than a 1.35 loaded 119.
wouldn't it be more efficient in speed and distance due to the higher momentum ??
scissors beat paper, paper beat rock, rock beat wingsuit - KarlM
I don't want to get suckered into the "what is more efficient" arguement, because at the stage you are at it doesn't matter. Just look at modern tandem canopies; They are bigger, often loaded less than you are, and may have thick dacron lines, not to mention the huge drogue and bag, and they can swoop nicely on no wind days, with no front riser input. I think that big of a wing, flown properly at your loading, will be fine with no additional drag-reducing methods.
Note, I think with your profile, you are likely to get hurt under this wing. Also note, RDS is not without drawbacks, the first of which is sacrificing opening reliability.
Note, I think with your profile, you are likely to get hurt under this wing. Also note, RDS is not without drawbacks, the first of which is sacrificing opening reliability.
frost 1
Since you aren't wrong then you must have the experience to speak with authority. Do you have a degree in aerospace engineering or aeronautics? Do you design anything with wings as a hobby or as a job? If yes, then you can answer your own questions (and educate us in the process). If not, then this can lead into more hypothetical grounds then actual facts.
I am saying that the size of cells on a conventional 200+ sq ft 9-cell will create so much drag that even with the correct loading or rather most efficent for the task at hand (speed and distance of a swoop, i am guessing) it will slow down and stop way before a smaller wing loaded the same.
I would guess that if they create a 230 sq ft thin profile wing similar to a VX or Velo loaded at 2.2-2.4 it will go the distance, but i am convinced that 230 sq ft Crossfire will not outperform a 130 X-fire loaded the same.
In the end, i think unless you can answer your own questions and prove what i said above was wrong, I think i will stick with my opinion.
I am saying that the size of cells on a conventional 200+ sq ft 9-cell will create so much drag that even with the correct loading or rather most efficent for the task at hand (speed and distance of a swoop, i am guessing) it will slow down and stop way before a smaller wing loaded the same.
I would guess that if they create a 230 sq ft thin profile wing similar to a VX or Velo loaded at 2.2-2.4 it will go the distance, but i am convinced that 230 sq ft Crossfire will not outperform a 130 X-fire loaded the same.
In the end, i think unless you can answer your own questions and prove what i said above was wrong, I think i will stick with my opinion.
SoFPiDaRF - School of Fast Progress in Downsizing and Radical Flying. Because nobody knows your skills better than you.
QuoteI am saying that the size of cells on a conventional 200+ sq ft 9-cell will create so much drag that even with the correct loading or rather most efficent for the task at hand (speed and distance of a swoop, i am guessing) it will slow down and stop way before a smaller wing loaded the same.
Why? Are the cells on the smaller wing so small that they don't allow that many air molecules through?
If the loading per square foot is the same, then the only factors to consider are drag created by other components. The bag and PC on a bigger canopy will be almost indectical in size to a smaller canopy. The lines will be longer on a bigger wing, but not as proportionally bigger as the wing (a 200 sq ft canopy's lines are not twice as long as a 100 sq footers). The frontal area of the pilot will also be proportionally smaller; when poeple get bigger, they tend to be rounder, hiding more of their area from the relative wind.
Quotethen this can lead into more hypothetical grounds then actual facts.
It the end, most of what's discussed here is hypothetical, as most jumpers do not posses the aeronautical degrees you speak of, and if they did, they would be smart enough to realize that short of wind tunnel testing, canopy aerodynamics are largely hypothetical becasue in the real world testing that we can perform, the variables from weather and the pilot combined with a limited amount of relaible instrumentation makes any data somewhat less than factual.
However, I have jumped a shitload of canopies, and swooped a shitlaod of canopies in different sizes with WL's from 2.5+ to under 1.0, which in skydiving is pretty much how you gain the authority to speak of such matters.
Now respect my author-i-ty!
I guess what I don't understand is what you are worried about. Are you concernced tht you won't get the performance out of it? Given what you fly now its going to feel like a rocket. Until you have hundreds of jumps on a canopy you won't know what little difference lines, RDS, or the extra jumpsuit bag feels like anyhow. I think you are worrying about things that are of little concern to you.
If you are not already performing speed generating landings (double fronts & FR 90s) and doing them damn consistently, you really should not even consider a high performance canopy. A XF at 1.4 is no canopy to start learning swoops on, even a barge that size.
Also, if you cannot slow down to 120 or so to deploy you've got much bigger concerns than line drag to consider. 160 is almost the limit of operational integrity of most gear (275 is the highest sport TSO), and none of it is tested with more than 275#s in the harness. 160 is freefly speed so if you can't reliably slow down to below that you are just rolling the dice. I know for sure that I would not jumnp if I thought there was a good chance on ewach jump that I would be opening at FF speed.
Side note: I had a xf 149 that I loaded at 1.8. It opened great and swooped a long way.
Be careful.
If you are not already performing speed generating landings (double fronts & FR 90s) and doing them damn consistently, you really should not even consider a high performance canopy. A XF at 1.4 is no canopy to start learning swoops on, even a barge that size.
Also, if you cannot slow down to 120 or so to deploy you've got much bigger concerns than line drag to consider. 160 is almost the limit of operational integrity of most gear (275 is the highest sport TSO), and none of it is tested with more than 275#s in the harness. 160 is freefly speed so if you can't reliably slow down to below that you are just rolling the dice. I know for sure that I would not jumnp if I thought there was a good chance on ewach jump that I would be opening at FF speed.
Side note: I had a xf 149 that I loaded at 1.8. It opened great and swooped a long way.
Be careful.
jakee 1,584
Quotewouldn't it be more efficient in speed and distance due to the higher momentum ??
That's what I'm saying. The higher momentum of the package will more than cancel out the increased drag since there will be proportionally less parasitic drag. As Dave said, the lines may be slightly longer but not twice as long, and they aren't any wider either.
Blindbrick, I think you are barking up the wrong tree, and in my newbie opinion you should leave the canopy as it is.
Do you want to have an ideagasm?
Quote***I'm actually going for a 1.3-1.35 WL and barring bad luck, I will be at 300+ jumps by the time I take delivery***
This is another area where you may run into problems. Buying gear based on future weight loss and/or jump numbers almost never works out the way you plan. Just something to think about.
Fortunately, my Icarus dealer is my DZO. My wait is a concern to him, and I know he won't release the canopy to me until I'm at that wait. On a similar note, the two instructors I am learnig HP stuff under wouldn't allow me to jump it until they were sure Iw as ready.
-Blind
"If you end up in an alligator's jaws, naked, you probably did something to deserve it."
frost 1
Quote
However, I have jumped a shitload of canopies, and swooped a shitlaod of canopies in different sizes with WL's from 2.5+ to under 1.0, which in skydiving is pretty much how you gain the authority to speak of such matters.
Now respect my author-i-ty!
No. I am not convinced.
SoFPiDaRF - School of Fast Progress in Downsizing and Radical Flying. Because nobody knows your skills better than you.
Icarus has a 500 jump min. for an Xfire2, so I'm sure performance will not be an issue. Rigging in the air has its dangers, especially at lower jump numbers.. fly the stock canopy.
On the free fall speed- obviously, dress for success. I know plently of bigger dudes (280+) that have had no issues with deployment speed.. but they pack neatly and wear a suit or drag, as well as focused on belly skills for deployment.
If you go RDS- there is just so much canopy still that its a minor benifit too the over equation. In essence its like trying to tell a canopy on a performance level from 1.34 to 1.36- id be fairly suprised if that makes a significant diffrence.
Good luck on the choices you make, but remember 1.4 WL is a performance WLing- I want an Xfire2 in that department of 1.45 but i'm waiting still for a while because unfortunetly shit happens out there.
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