Forums: Skydiving Disciplines: Swooping and Canopy Control:
Paraglider Vs Parachute

 

First page Previous page 1 2 Next page Last page  View All

bqmassey  (Student)

Jun 24, 2011, 9:39 AM
Post #1 of 36 (6545 views)
Shortcut
Paraglider Vs Parachute Can't Post

I've quickly discovered that canopy flight is the part of skydiving that makes me feel most in-over-my-head as far as knowledge and understanding go. I have a lot of questions.

Obviously a paragliding wing and a skydiving parachute have several differences. One obvious difference is the shape. All the wings I've seen have have been very elliptical, with a large aspect ratio.

What other differences are there? From what I understand, they're made out of a less robust material.

What about a paraglider allows it to hang up there for a long time and make good use of thermals? Is glide ratio a factor on it's own, or is it really the descent rate that matters (with glide ratio only a contributing factor in descent rate)? For instance, a small, high performance parachute may have a fairly flat glide ratio. However, if it is traveling down that glide ratio very quickly it may have a descent rate faster than a big, slow canopy that has a steep glide ratio. Which would thermal better?

I have a lot of other questions about canopies and canopy flight, but let's start with that. I have a lot to learn, and would enjoy discuss this with those of you that take a similar interest in canopy flight.


Calvin19  (D 29712)

Jun 24, 2011, 10:42 AM
Post #2 of 36 (6498 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
I've quickly discovered that canopy flight is the part of skydiving that makes me feel most in-over-my-head as far as knowledge and understanding go. I have a lot of questions.

Obviously a paragliding wing and a skydiving parachute have several differences. One obvious difference is the shape. All the wings I've seen have have been very elliptical, with a large aspect ratio.

What other differences are there? From what I understand, they're made out of a less robust material.

What about a paraglider allows it to hang up there for a long time and make good use of thermals? Is glide ratio a factor on it's own, or is it really the descent rate that matters (with glide ratio only a contributing factor in descent rate)? For instance, a small, high performance parachute may have a fairly flat glide ratio. However, if it is traveling down that glide ratio very quickly it may have a descent rate faster than a big, slow canopy that has a steep glide ratio. Which would thermal better?

I have a lot of other questions about canopies and canopy flight, but let's start with that. I have a lot to learn, and would enjoy discuss this with those of you that take a similar interest in canopy flight.

The factors are endless, but in less than technical terms the big things are:

Paragliders have:
-higher aspect ratio (thinner) (parachute 2-3/1, paraglider 4-13/1
-more surface area (generally) (Parachute 39-300'^2, Paraglider ~170-320'^2)
-shallower trim
-MUCH better airfoil shape integrity

These things and many others make them as efficient in soaring flight as they are.

The fabric used on a paraglider is not "less robust", just different. It is a essentially zero stretch sail material, where a parachute uses a semi-flexible material to increase strength on openings. Other differences are harness drag, etc. I could go on.


(This post was edited by Calvin19 on Jun 24, 2011, 10:44 AM)


Calvin19  (D 29712)

Jun 24, 2011, 10:54 AM
Post #3 of 36 (6490 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

I have soared a 260'^2 (.7/1) BASE canopy, as well as a 70'^2 Speed glider (loaded at 2.3/1). Depends on the lift, and how comfortable you are in that kind of air.

Parachutes for the most part top out in glide ratio around 5/1, at a very high descent rate, (I think about 700'/min, not sure though never did the math, but when maneuvering that descent rate could get well above 6000'/min. I have seen over 100mph vertical speed under canopy) Modern paragliders get 8-11/1 glide at around 200ft/min sink, with the more important ability to maneuver in tight conditions at that sink rate.


AggieDave  (D License)

Jun 24, 2011, 2:10 PM
Post #4 of 36 (6456 views)
Shortcut
Re: [Calvin19] Paraglider Vs Parachute [In reply to] Can't Post

I'm just waiting for someone to stop dicking around and make a competition canopy for the distance event in CP based on a paraglider. Something that will survive a sub-terminal opening, can dive and will fly forever.

We already have people switching canopies for events and putting on slick style competition freefall suits for speed runs...


Premier LouDiamond  (D 25931)
Moderator
Jun 24, 2011, 2:50 PM
Post #5 of 36 (6445 views)
Shortcut
Re: [AggieDave] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
I'm just waiting for someone to stop dicking around and make a competition canopy for the distance event in CP based on a paraglider. Something that will survive a sub-terminal opening, can dive and will fly forever.

We already have people switching canopies for events and putting on slick style competition freefall suits for speed runs...


Something with a 6:1 GR, kinda like this?Smile


AggieDave  (D License)

Jun 24, 2011, 3:13 PM
Post #6 of 36 (6437 views)
Shortcut
Re: [LouDiamond] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
In reply to:
I'm just waiting for someone to stop dicking around and make a competition canopy for the distance event in CP based on a paraglider. Something that will survive a sub-terminal opening, can dive and will fly forever.

We already have people switching canopies for events and putting on slick style competition freefall suits for speed runs...


Something with a 6:1 GR, kinda like this?Smile

Holy-endcell-collapse-batman!

Yeah, but smaller, faster and do we have to pay extra because it's "tactical?"


Calvin19  (D 29712)

Jun 24, 2011, 3:31 PM
Post #7 of 36 (6433 views)
Shortcut
Re: [AggieDave] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
Yeah, but smaller, faster and do we have to pay extra because it's "tactical?"

Doesn't work like that. The simple explanation is Drag.

Parasite drag increases at an exponential rate, and any ram air canopy is a DOG. Induced drag decreases exponentially with speed. The balance of the two is the goal for any soaring aircraft design.

The smaller the canopy, or more accurately the smaller the effective span, the less efficient it will be at soaring.

Take a look at modern racing paragliders. The BEST gliders are loaded to <1lb/sq foot. Speed kills.

I have thought a lot about that though, Taking a miniwing into a swooping comp. But, even a SUPER high loaded glider will still fly like a glider, not a swooping canopy. You would have to kit the gate sideways, and burn a lot of energy trying to go straight.

If you could count the total flight distance, not the straight line distance, after hitting the gate Then we might be onto something.


Premier LouDiamond  (D 25931)
Moderator
Jun 24, 2011, 3:33 PM
Post #8 of 36 (6431 views)
Shortcut
Re: [AggieDave] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
In reply to:
In reply to:
I'm just waiting for someone to stop dicking around and make a competition canopy for the distance event in CP based on a paraglider. Something that will survive a sub-terminal opening, can dive and will fly forever.

We already have people switching canopies for events and putting on slick style competition freefall suits for speed runs...


Something with a 6:1 GR, kinda like this?Smile

Holy-endcell-collapse-batman!

Yeah, but smaller, faster and do we have to pay extra because it's "tactical?"


That's actually a technique called "Big Ears" in the para gliding world. There is one that is smaller and still has all the same performance numbers. However, its limited to military only sales.


AggieDave  (D License)

Jun 24, 2011, 3:55 PM
Post #9 of 36 (6424 views)
Shortcut
Re: [LouDiamond] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
That's actually a technique called "Big Ears" in the para gliding world. There is one that is smaller and still has all the same performance numbers. However, its limited to military only sales.

Great, only G-dub will have one then...Just what he needs, more cool stuff!Laugh


jonmurrell  (C 36522)

Jun 24, 2011, 4:26 PM
Post #10 of 36 (6415 views)
Shortcut
Re: [LouDiamond] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
Something with a 6:1 GR, kinda like this?Smile

Can you freefall it beyond sub-terminal? The spec sheet only talks about 6-10s delays... 10s is practically terminal anyways.


Premier LouDiamond  (D 25931)
Moderator
Jun 24, 2011, 4:42 PM
Post #11 of 36 (6411 views)
Shortcut
Re: [jonmurrell] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
In reply to:
Something with a 6:1 GR, kinda like this?Smile

Can you freefall it beyond sub-terminal? The spec sheet only talks about 6-10s delays... 10s is practically terminal anyways.

Yes, the 6-10 sec delay is suggested when you are jumping from 25k feet MSL. It is a terminal free fall system designed to be opened up high for HAHO applications. I've jumped it from 12k opening at 6k and had about a 30 min canopy ride. I basically got tired of flying around and forced it to land, its an incredible canopy.


jonmurrell  (C 36522)

Jun 24, 2011, 6:54 PM
Post #12 of 36 (6391 views)
Shortcut
Re: [LouDiamond] Paraglider Vs Parachute [In reply to] Can't Post

Wow, that's incredible. There's got to be a con though, or someone would've copied or scaled it by now... how was the opening?


yoink

Jun 25, 2011, 12:24 AM
Post #13 of 36 (6374 views)
Shortcut
Re: [Calvin19] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:

Parasite drag increases at an exponential rate, and any ram air canopy is a DOG. Induced drag decreases exponentially with speed. The balance of the two is the goal for any soaring aircraft design.

Making ever more efficient designs based on the current technology, that's true. Eventually you'll reach a performance plateau.

However I woldn't be surprised if the current path of making flatter and flatter designs leads to a hybrid ram-air / hangglider type of wing, rather than the paraglider crossover - something that once inflated is essentially rigid, closed and thin. I've been drawing designs like that for the past 3 years and I'm not a specialist. Someone else must be doing more.

Would it fit in a cool, tiny container? Probably not. Would it glide like a bastard? Who knows? WinkCool I'd fly it! Sly


for the OP, I tend to think of both paragliding and canopy piloting as having the same basic principles, in the same way that Formula 1 and Rallying have the same background, but each becomes its own specialty with gear, techniques and training specific to it.
It's massive hubris to think becase you can do one, you can do the other.


(This post was edited by yoink on Jun 25, 2011, 12:27 AM)


AggieDave  (D License)

Jun 25, 2011, 5:10 AM
Post #14 of 36 (6355 views)
Shortcut
Re: [yoink] Paraglider Vs Parachute [In reply to] Can't Post

Quote:
Would it fit in a cool, tiny container? Probably not

You should see the rigs the little guys were wearing when the all-sail JVX hit the market. It looked like they were in really well color matched student rigs!

Quote:
It's massive hubris to think becase you can do one, you can do the other.

There are a few cross over pilots that I know, but I don't think they are near the level of accomplishment under a PG wing that they are in the competitive swooping world.

Contrary to the opinion of some low time jumpers on DZ.com: swooping is hard and takes a long time of dedicated study to become just OK at it.


Premier LouDiamond  (D 25931)
Moderator
Jun 25, 2011, 7:01 AM
Post #15 of 36 (6338 views)
Shortcut
Re: [jonmurrell] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
Wow, that's incredible. There's got to be a con though, or someone would've copied or scaled it by now... how was the opening?

Openings are very slow and soft as it is made to be opened at altitudes above 20k feet MSL, it is also 380 sq ft. so it is a big canopy. Some may consider that a con in the sport world but it's a purpose built system for military applications. Even if they made them available to the public and made them in say a 170 sq ft or smaller, it wouldn't be a canopy that you could use for everyday jumping. This canopy does not want to come out of the sky and you can ride updrafts with it quite easily. You could quite easily create canopy traffic issues in the sky because of how long it stays aloft plus that fact that it's built for distance, the canopy pilot would have to force the canopy to land. It would also take an extremely experienced person to swoop this canopy given it's design and flight characteristics,so that could be considered a con I suppose and probably the reason why most swoop canopies are more ground hungry and don't have as flat a glide.


Calvin19  (D 29712)

Jun 25, 2011, 8:07 AM
Post #16 of 36 (6330 views)
Shortcut
Re: [LouDiamond] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
It would also take an extremely experienced person to swoop this canopy .

http://www.youtube.com/...ed&v=YhlNoJK7EIg

130~ sq foot acro paraglider. The pilot, Pal is most likely the best glider pilot in the world right now. He is an awesome guy and really fun to hang with.

Take a look at the "swoop" at the end. And that one is pretty weak.


Rigless

Jun 25, 2011, 10:28 AM
Post #17 of 36 (6309 views)
Shortcut
Re: [Calvin19] Paraglider Vs Parachute [In reply to] Can't Post

Pretty impressive crazy shit..

http://www.youtube.com/watch?v=X2qOXJdLqU4


bqmassey  (Student)

Jun 26, 2011, 1:54 PM
Post #18 of 36 (6252 views)
Shortcut
Re: [Rigless] Paraglider Vs Parachute [In reply to] Can't Post

Awesome info guys. Thanks!

Would I be correct in saying that the only thing that affects a canopies ability gain altitude in a thermal is it's descent rate, not glide ratio? If so, two canopies with the same descent rate but vastly different glide ratios would have the same ability to soar. The only difference would be that the higher glide-ratio canopy would have a faster ground speed (and could travel farther) than the canopy with a steep glide ratio.

The PG wings are so long and elliptical. Some of them can pull off some insane maneuvers (like in those videos), but I would imagine that the student/beginner wings are much more docile even though they maintain a similar planform. So, what is it that makes the responsive ones so responsive?


bqmassey  (Student)

Jun 29, 2011, 5:10 AM
Post #19 of 36 (6130 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

No additional thoughts?


AdD  (D License)

Jul 8, 2011, 11:36 AM
Post #20 of 36 (5961 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

Line length, aspect ratio of the wing, area of wing


Calvin19  (D 29712)

Jul 8, 2011, 3:15 PM
Post #21 of 36 (5940 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
Would I be correct in saying that the only thing that affects a canopies ability gain altitude in a thermal is it's descent rate, not glide ratio?

No, Soaring in any condition other than a fixed area of lift like a ridge, wave, or convergence (or a single thermal) are the only way you could soar a low glide ratio/low airspeed/low sink rate canopy. good slow sink rate with a good glide WITH speed is the best way to soar. the most efficient soaring machines have a sink rate of 100ft/min, glide at over 50/1, and at those glides and sink rates fly 60mph with the ability to dive at 150mph+

http://vimeo.com/19877748


bqmassey  (Student)

Jul 10, 2011, 10:08 AM
Post #22 of 36 (5885 views)
Shortcut
Re: [Calvin19] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
In reply to:
Would I be correct in saying that the only thing that affects a canopies ability gain altitude in a thermal is it's descent rate, not glide ratio?

No, Soaring in any condition other than a fixed area of lift like a ridge, wave, or convergence (or a single thermal) are the only way you could soar a low glide ratio/low airspeed/low sink rate canopy. good slow sink rate with a good glide WITH speed is the best way to soar. the most efficient soaring machines have a sink rate of 100ft/min, glide at over 50/1, and at those glides and sink rates fly 60mph with the ability to dive at 150mph+

http://vimeo.com/19877748

Thanks for the reply.

I'm a little confused. You're saying that the only way you could soar something that has a poor glide ratio is within an area of lift, correct?


Calvin19  (D 29712)

Jul 10, 2011, 1:43 PM
Post #23 of 36 (5861 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

Correct. Within an area of constant lift. Generally soaring involves traveling between areas of lift. It's still soaring, i guess, but at that point there is nothing to it.

Sorry, my post was poorly worded. I do that sometimes.


bqmassey  (Student)

Jul 10, 2011, 4:45 PM
Post #24 of 36 (5846 views)
Shortcut
Re: [Calvin19] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
Correct. Within an area of constant lift. Generally soaring involves traveling between areas of lift. It's still soaring, i guess, but at that point there is nothing to it.

Sorry, my post was poorly worded. I do that sometimes.

Ah, ok.

So, while you're in an area of lift, the major component that determines your ability to gain altitude is the descent rate of the system.

Outside of an area of lift, you'd prefer a flat glide ratio over a slow descent speed, as the glide ratio will help you get to the next lift provider.

Why is it preferrable to travel down that glideslope at a higher rate of speed? Just to penetrate a head wind better?


Calvin19  (D 29712)

Jul 10, 2011, 5:24 PM
Post #25 of 36 (5832 views)
Shortcut
Re: [bqmassey] Paraglider Vs Parachute [In reply to] Can't Post

In reply to:
Why is it preferrable to travel down that glideslope at a higher rate of speed?
Speed over glide to penetrate a headwind or get through an area of sink.

There has been entire textbooks written about that subject, check out the wiki page.
http://en.wikipedia.org/wiki/Speed_to_fly


First page Previous page 1 2 Next page Last page  View All

Forums : Skydiving Disciplines : Swooping and Canopy Control

 


Search for (options)