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lightweight skydiver, needs advice on canopy

 


andy2

Apr 9, 2003, 7:17 AM
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lightweight skydiver, needs advice on canopy Can't Post

Bear in mind that I only have 3 jumps so far, so thinking about my first rig is still very theoretical, but here goes...I only weigh 125 pounds without gear. So I'm thinking I'm going to be needing a MUCH smaller canopy than say someone that weighs 180 or so. The canopy I used on my first jump felt like it was much to big, but hey, it was my first jump. Then they downsized me to a smaller one, and I really couldn't tell how good I was controlling it (high winds, etc). My question is would it be smart for me to be thinking about a small(er) canopy than normal people who weigh 60-70 pounds (at least) more than me? Thanks, I appreciate your feedback.


CrazyIvan  (A 43359)

Apr 9, 2003, 7:30 AM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Well my friend, you should keep a 1:1 wingloading, so, let's assume your rig will weight 25 Lb, the canopy size for you would be a 150.


John4455  (D 22657)

Apr 9, 2003, 7:31 AM
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The best advice is to talk to youir instructors and take their advice. John Hayes won't steer you wrong.


Premier wmw999  (D 6296)

Apr 9, 2003, 7:34 AM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

There's a whole lot of information available, and most of it is probably still in the future. But overall, there are two pieces of information that are important:
1. Yes, you're lighter, and what's a hot canopy for one person will be somewhat milder for you
2. The fact that the lines are shorter on a smaller canopy, and the wing smaller overall, means that it doesn't scale exactly -- a canopy that you load 0.9:1 will be FAR less "sluggish" than one that someone who weighs 210 geared up loads at 0.9:1.

So when the time comes, don't pay as much attention to numbers. There's a lot of good information here on dz.com, and some of the manufacturer's websites.

Wendy W.


DYEVOUT  (Student)

Apr 9, 2003, 8:43 AM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Haven't bought my rig, yet - but I think it wise to rely more on your instructors for advice, than some unseen entity on the web. I, too, have asked canopy questions here for information purposes - but come final decision time, I want data from someone who has seen me fly, and has an idea of my abilities as a canopy pilot.

A fellow rookie's opinion.


CanuckInUSA  (D 26396)

Apr 9, 2003, 8:56 AM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Wendy has already touched on how two canopies loaded the same will not perform the same (ie: the smaller canopy being zippier than the larger), but here's a good article from PD http://www.performancedesigns.com/docs/wingload.pdf that you should read.


(This post was edited by CanuckInUSA on Apr 9, 2003, 8:59 AM)


Premier billvon  (D 16479)
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Apr 9, 2003, 9:18 AM
Post #7 of 16 (1038 views)
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

>My question is would it be smart for me to be thinking about a smal
>l(er) canopy than normal people who weigh 60-70 pounds (at least)
> more than me? Thanks, I appreciate your feedback.

Yes and no.

Yes, you will, in general, be happy with a smaller canopy than someone who is heavier than you. However, most skydivers measure their canopy's size relative to them by wing loading - in other words, how many pounds per square feet their canopy carries. A jumper who weighs 150 pounds jumping a 100 square foot canopy has a loading of 1.5 to 1.

Most lighter people are happier with _lighter_ wing loadings than heavier people. In other words, you may be just as happy at a wingloading of 1 to 1 as a heavier jumper might be at 1.5 to 1. You'll still end up with a smaller canopy, but not too much smaller.

An example - let's say that sometime in the future your friend, with the same experience/skill that you have, weighs 200 pounds and buys a 190 sq ft canopy. His exit weight will be around 230, so he will load his canopy at 1.2 to 1. Everything being equal, you may be just as happy with a canopy loaded at 1 to 1, which for you would be around 160 square feet. Your canopy would be smaller than his, but you will not be wing-loading your canopy as much as he is.

In any case, the size of canopy you end up buying should be based primarily on your skill and experience, not by any formula. As you progress as a skydiver, and learn to fly smaller canopies, you will have a good idea of what you want and what you can handle. I would strongly recommend a canopy control course at some point - it can both save your life and make your canopy progression a lot smoother.


rigging65  (D 21921)

Apr 9, 2003, 9:51 AM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Something else you should keep in mind about smaller canopies... they have shorter lines.

Shorter lines = faster pendulum effect (which is the effect of swinging out from under the canopy when turning). Since you get out there faster (as you have a shorter distance to go) your turn rate on a given canopy will be faster than on the same model canopy, loaded the same, but bigger.

People are often told they should start on a canopy loaded at about 1.1, but that often puts light jumpers on a 120 or smaller, and they simply aren't comfortable there. It's generally not the ground speed from wing loading, it's that you don't feel like you have control of the canopy...mostly because the rate of turn is fast, so it makes controlling it touchy.

In very general terms, heavier people will tend to have problems with ground speed before they run into rate-of-turn problems, whereas lighter people will tend to run into over-control problems before over-speed problems.

What all this equals out to for you, is that you may be best suited to a canopy that's loaded even lighter than 1.0. The only real concern about loading this light is that you have to be very conscience of what the winds are doing...lightly loaded (under 1.0) can have you flying backwards in winds that wouldn't give other jumpers any problems.


andy2

Apr 9, 2003, 10:35 AM
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Re: [rigging65] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

will this pendulum effect be as dramatic as someone that is substantially heavier? After all, their descent rate will be faster, correct? And also the momentum of the turn will be greater due to their larger mass? I guess it's pretty much water under the bridge though, as I am going to just listen to what my instructors say until I get a LOT more experience.


CrazyIvan  (A 43359)

Apr 9, 2003, 10:37 AM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

In reply to:
will this pendulum effect be as dramatic as someone that is substantially heavier? After all, their descent rate will be faster, correct? And also the momentum of the turn will be greater due to their larger mass? I guess it's pretty much water under the bridge though, as I am going to just listen to what my instructors say until I get a LOT more experience.

Nothing wrong with asking around, you'll get some useful and not so useful info which you can then compare to what your instructors have to say.

There is never such thing as a stupid question or stupid answer, it's all knowledge.


jerm  (D 23994)

Apr 9, 2003, 12:42 PM
Post #11 of 16 (961 views)
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

In reply to:
will this pendulum effect be as dramatic as someone that is substantially heavier? After all, their descent rate will be faster, correct? And also the momentum of the turn will be greater due to their larger mass?

well it takes more time/energy to move that larger mass. As such a 120 may be titchier for you than for someone who is leading it more heavily, because the canopy has to do more in order to move their big ass.

the problem becomes one of how much input you need to put in for how much of a response... a small canopy generally requires less input to get things done than a larger canopy. THis can be a lot of fun up in the air, but can be a real problem when it comes to landing, when just i slight unevenness in your flare may send you tumbling or worse. Small changes in the air (gusts, turbulence) will require more corrections than on a larger canopy, and overcorrecting on a small canopy can have disastrous results, even at a low loading.

The short version that many have already said is that there's a lot more to it than just simple wingloading. Work your way down in size just like everyone else... don't play a "numbers game" trying to get to the "proper" wingloading. The proper wingloading for you is what you're safe flying, not some number generally based one people of different sizes and shapes.


darkwing  (D 4164)

Apr 9, 2003, 2:53 PM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Not all canopies are created equal, even if the same square footage. I recommend a not-too-zoomie canopy such as a small Spectre. They are relatively mellow to handle compared to other canopies of the same size. I think they make them down to about 120 or so.


rigging65  (D 21921)

Apr 9, 2003, 4:12 PM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Quote:
I guess it's pretty much water under the bridge though, as I am going to just listen to what my instructors say until I get a LOT more experience.

That's an excellent idea, but it never hurts to gain knowledge and get some ideas to talk over with your instructor.

Pendulum effect is most greatly effected by the length of the lines, not the mass at the end (within reason). If you have a light weight on a short string and a heavy weight on a long string, which one moves faster from point A to point B? The answer is the short string, it's simply got less distance to travel (again, within reason), and this is a larger factor in determining turn rate than is wing loading.

A heavier mass will move along the path faster than a lighter mass, given the path is the same length...but now we're talking apples and oranges (ie - we're not talking about pure pendulum effect with equal wingloadings anymore). What you (should be) concerned with is A) At what ground speed and I comfortable? (and can I get away with screwing up and not get killed) and B) How much control range do I need in my steering lines to be comfortable (this is where a smaller canopy can give you trouble, as the lines are shorter and yadda yadda yadda).

Since 7-cell canopies (like Spectres and Synergys) tend to have a longer control range by design, they tend to be more forgiving in the smaller sizes. This is because it takes more input to get the desired result, so it gives you a less "touchy" canopy.

7-cell vs. 9-cell is a whole separate argument. One that I encourage to ask questions about and learn more about, but it's beyond the scope of your question to go further with it.

Ask people you trust...Instructors and Riggers are great, but ask more than one...and work your way down at a comfortable pace. Remember, you're skydiving to have fun, not to see how fast you can downsize!Wink


Premier Tonto  (D 515)
Moderator
Apr 10, 2003, 2:07 AM
Post #14 of 16 (868 views)
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

Wendy has given good advice. Some insructors will try and "accelerate" your progression because of your weight. Having started lower down the scale - this will mean you cover more distance on the scale in the same amount of time as other jumpers. Women are familiar with this as the big guys are always telling them to downsize because of what THEY would be jumping at that weight. Take your time. The only reason to want to go smaller is to want to go faster.

t


nightjumps  (D 23385)

Apr 10, 2003, 6:24 AM
Post #15 of 16 (848 views)
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

You've received a lot of good advice here:

1. 1:1 or less (preferably a little less).

2. Talk to those instructors who've seen you land for advice.

My $.02 is;

1. After you get off student status, borrow or demo something < .75:1 for at least five hop & pop jumps from 6-7.5K feet while using a radio with an instructor. This way your total focus is on canopy control.

2. On each of those HNPs, incrementalize your way back through the canopy control portions of your student training (Toggle turns, riser turns stowed, riser turns unstowed, front riser turns.... etc.) Do several practice flares at the top. You will not have anything relative, but will get a sense of the stall point as you toggle down.

3. Setup for a nice downwind, base & final straight-in approach.

4. On landing - feel the flare (match your toggle down pressure with the speed of the ground coming up at you).

5. Finally, consider a semi-elliptical for your first year in the sport. They are a *little* more forgiving on the bottom end than fully ellipticals.

Recognize that parachutes have become considerably more "opening" reliant over the past ten years but the incident reports are respite with skydivers downsizing too fast (exceeding the weight-loading and parasitic drag) too soon in their path of progression. Which means be very conservative weight-loading and landing for the first year or two.

Step down conservatively (.6:1, .75:1, .9:1, 1:1, etc.)and repeat steps 1-4.

...Bigun


(This post was edited by nightjumps on Apr 10, 2003, 6:26 AM)


pilotdave  (D License)

Apr 10, 2003, 2:24 PM
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Re: [andy2] lightweight skydiver, needs advice on canopy [In reply to] Can't Post

I'm a little lighter than you. I bought a PD150 (F111) and am perfectly happy with it. I made my first jump on a PD170, but then switched DZs and went up to a 230 (the smallest they had). Since I had no problem flying the 170 on my first jump, I'm sure I could handle something smaller than a 150 now, 80 jumps later, but I have absolutely no desire to downsize (other than to get a canopy that fits in my container more easily). Don't go smaller than you're comfortable with. Trust me you can have PLENTY of fun without a lot of wing loading. I only load the 150 at about .8 or so (a little more when i wear weight Smile), but it's a completely different experience than the PD230s I used to jump.

I made a couple jumps a couple years ago on a manta 288 loaded around .45. The lack of control was just scary. I think a 360 degree turn would have taken a good 30 seconds or more.

So yes, you will want something smaller than most other jumpers, but don't go too small.

Dave



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