Is 1:1.8 wingload too high?

[Boris73 0]

I have 54 jumps, 36 of these done 2 years ago, and 18 done in the last month. I am looking at getting a 170 spectre to fit in a Mirage G4 M3, this will give me a wing load of 1:1.18, now is that too high or acceptable? I have just been looking at canopies tonight and so haven't had time to ask any instructors at my DZ.

[dragon2 0]

1:1.8 is totally different from 1:1.18

Still, 1.2 might be considered high for less than 200 jumps yes. Also important is what you've been jumping so far, what your instructors have to say, where you jump, and what the reserve in that rig is going to be. A M3 fits up to a PD160R which is way too small for you, now maybe you could fit a Optimum 176 in there if you're willing to wait a year to get it and it frankly would still be considered too small for you: you want a WL of 1.0 or lower for your reserve, ie a PD193R would be suitable.

Oh and you're not that current either. Yup, too small for both the main and definitely for the reserve!

ciel bleu,
Saskia

[jverley 0]

Just to clarify, wing loading is a ratio of Suspended weight to area of the parachute's planform. In your example, the wing loading would be 1.18, not 1:1.18. 1:1.18 indicates that you have 1.18 square feet of fabric over your head for every pound under it.

As far as is that number right for you - there is only one way to find out. Good luck.

John
Arizona Hiking Trails

[Couloirman 0]

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I have 54 jumps, 36 of these done 2 years ago, and 18 done in the last month. I am looking at getting a 170 spectre to fit in a Mirage G4 M3, this will give me a wing load of 1:1.18, now is that too high or acceptable? I have just been looking at canopies tonight and so haven't had time to ask any instructors at my DZ.

It wasnt too high for me at those numbers, but Im REALLY good at butt sliding YMMV

what was your wingloading/what canopy were you flying on your last 18 jumps? Dont buy a parachute without having either a) flown that same size/platform canopy several times and been totally comfortable under it, or b) having so many jumps on a canopy of a larger size that you just KNOW the next size down will be fine.(I dont think 18 jumps fits in this second category).

Isn't there a 170 rental rig at your DZ? Rent it, fly it and report back!

[Boris73 0]

yeah the 1:1.8 was a typing error. I am going to ask my instructor next week. If I go with a Triathlon 175 I will have a wingload of roughly 1:1.14 which is acceptable in my eyes, but again will ask my instructor. This is all hypothetically speaking, as I weigh 176lbs, and I am assuming I will have an exit weight of 200lbs.

[JohnMitchell 14]

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Just to clarify, wing loading is a ratio of Suspended weight to area of the parachute's planform. In your example, the wing loading would be 1.18, not 1:1.18. 1:1.18 indicates that you have 1.18 square feet of fabric over your head for every pound under it.

As far as is that number right for you - there is only one way to find out. Good luck.

No, I think he expressed it in a commonly accepted format. Of course, the formula is weight/area, giving us a "pounds per square foot" number when using American measurements. I've heard people say "I'm loading 1 to 1.5 . . . " Most of us just shorten it to "I'm loaded at 1.5 . . ."

I know that "1 to 1.5" could be considered backwards, since you're talking "area to weight" but once again, it seems to be the accepted usage, not confusing to anyone.

As far as should he be jumping that loading, I don't think so. I hate to see downsizing decisions made by what gear is available rather than by what gear is best for me. You and I have both done enough first aid to know it's not always a good idea.

[Chubba 0]

I would say go buy a 190 or possibly a 210 depending on how current you're intending to be (you have done both extremes it seems).

The 190 will still be loaded close to 1.0, would be a perfect loading to learn on.

No need to jump to 1.2 loading after 20 jumps.

[hackish 8]

At 185lbs without the rig and 40 jumps I was flying a sabre2-170. People online thought I was a DGIT just based on the numbers. Now 300 jumps later I'm still standing up every landing and doing just fine. Conversely someone else has 150 jumps and is on a sabre 170 (I think) and when he visits he probably won't stand it up and we always wonder if he'll put it down in our field or the next.

Who can tell you if you're ready for something based on some stats posted on the interweb? Nobody. Go see a few instructors who've seen your progression in person, who can see your landings and give you competent advice based on your skills not your stats.

-Michael

[Chubba 0]

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At 185lbs without the rig and 40 jumps I was flying a sabre2-170. People online thought I was a DGIT just based on the numbers. Now 300 jumps later I'm still standing up every landing and doing just fine.

That's beside the point.

High winds aside, you would have been safer in every single scenario under a Sabre2 190 or 210.

I don't see any reason why the OP should load over 1.0 given his situation. It's not hard or expensive at all to buy 2nd hand, put 100 jumps on a canopy then sell/downsize.

[brettski74 0]

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No, I think he expressed it in a commonly accepted format.

I don't think anyone is commenting on whether or not it is valid to express a ratio in n:m form, however, he has made a very valid and correct point in that the OP is expressing the ratio backwards. If we're understanding him correctly, his suspended weight in pounds is roughly 1.18 times the square footage of the canopy he is contemplating - around 200 pounds. This gives a wing loading of 1.18:1, which may be spoken as 1.18 to 1. Note the order of the two numbers as this is important. A ratio of 1:1.18 is the inverse of this number, or roughly 0.85:1, which would indicate that his suspended weight was closer to 144 pounds. It's also common when the ratio has been normalised such that the second number in the ratio is 1 to simply drop the second number and refer to it as the first number only, which is why most people simple state that they have a wing loading of 1.18.

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I know that "1 to 1.5" could be considered backwards, since you're talking "area to weight" but once again, it seems to be the accepted usage, not confusing to anyone.

I disagree. Put the numbers backwards in a discussion, then have a newbie come along and you will probably confuse them about wing loading, how it's calculated and what an appropriate wing loading for a given person might be.

If skydiving was the only place in modern society where one might deal with ratios and they were always written/spoken backwards like that, I'd agree that this is not confusing, however, since ratio notation has a clearly defined and specific meaning in mathematics, that this is widely used in a number of areas of society and that people in skydiving may come from any of these backgrounds, I think it's somewhat important that people use correct terminology so that not only do we understand each other correctly, but we can also more easily teach these things to newcomers to the sport.

As for the original question, I'd also agree that a wing loading around 1.2 may be a little ambitious for someone with that level of experience and currency.

[headoverheels 291]

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I have 54 jumps, 36 of these done 2 years ago, and 18 done in the last month. I am looking at getting a 170 spectre to fit in a Mirage G4 M3, this will give me a wing load of 1:1.18, now is that too high or acceptable? I have just been looking at canopies tonight and so haven't had time to ask any instructors at my DZ.

Get a larger canopy. Basically, you have 18 jumps in a time frame that matters.

Advice is often what someone asks for when they already know the answer and don't like it.

[mjosparky 3]

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At 185lbs without the rig and 40 jumps I was flying a sabre2-170. People online thought I was a DGIT just based on the numbers. Now 300 jumps later I'm still standing up every landing and doing just fine.

This a quote from a friend of mine, and Wendy (wmw999) uses at her signature line.

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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)

Never mistake luck for skill. If you run out of luck before you have the skill you are fucked.

Sparky

My idea of a fair fight is clubbing baby seals

[kmills0705 0]

+ 1

First, are you going to get a smaller canopy, get hurt and say "but the folks on dz.com said it was ok."

Secondly, just because someone doesn't get caught drinking and driving doesn't mean it is safe and ok.

Kim Mills
USPA D21696
Tandem I, AFF I and Static Line I

[klafollette 0]

You may want to read Brian Germain's dissertation on canopy downsizing. It will give you lots to think about when deciding on the appropriate size for your skill level.

http://bigairsportz.com/pdf/bas-sizingchart.pdf

[MarkM 0]

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At 185lbs without the rig and 40 jumps I was flying a sabre2-170. People online thought I was a DGIT just based on the numbers. Now 300 jumps later I'm still standing up every landing and doing just fine.

Good for you. There are plenty of people walking around with metal in them that weren't as lucky.

Also, I think "try it for bit and see how you feel" said elsewhere in this thread isn't the best advice. Odds are those landings will be on good weather days with a good spot, good traffic and easy landings.

I mean, if you want a real feel for how the canopy will perform, get out 10 seconds before the green light comes on and and see how well it lands in the Walmart parking lot

The OP is horridly uncurrent. No reason to be under a 170 anything when a 190 will be more forgiving of errors.

[klafollette 0]

Something else to note that Brian explains in his guide, wing loading alone doesn't explain it all. It depends on size and type of canopy. A 120 and 210 loaded at 1.2 will handle completely different. That's why he gives a particular size not wing-loading for a given # of jumps and weight.

Your profile doesn't show, but also depends on where you jump. A canopy will handle differently at sea level than Denver at 5K ASL. By Brian's guide, you should be jumping a 230, not a 170. I had a 230 for first 100 jumps, then a 210 (loaded 1.15) until I had 500 jumps, then downsized to a 190 for 100 jumps, then got a 170.

Sure, you might be fine on that 170 99% of the time, when there are no surprises. When you can stand up your landings 100% is not a good gauge of when to downsize. When the shit hits the fan; someone cuts you off on final, heading towards an unexpected obstacle, need to turn low, have a bad spot landing out, landing cross/downwind, you want to be 100% confident you can handle that canopy in every situation.

[hackish 8]

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At 185lbs without the rig and 40 jumps I was flying a sabre2-170. People online thought I was a DGIT just based on the numbers. Now 300 jumps later I'm still standing up every landing and doing just fine.

Good for you. There are plenty of people walking around with metal in them that weren't as lucky.

I think you've entirely missed the point. Lots of people online told me how I'd die under that canopy. All the instructors who watched said ok it's aggressive, be careful but it's not outside your capibilities.

My point is that a bunch of people online know nothing about an individuals ability to do something. Go see your instructors. Otherwise it's like asking me if a certain car is going to be too fast for you on a track. Sure I can say that Porsche Turbo is out of your range but the OP here isn't asking about a Velocity either.

A 170 could be within his range. Myself and a number of others at my DZ have been very successful on canopies of this size with low jump numbers. It is possible but a local instructor needs to make that call.

-Michael

[DrewEckhardt 0]

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I think you've entirely missed the point. Lots of people online told me how I'd die under that canopy. All the instructors who watched said ok it's aggressive, be careful but it's not outside your capibilities.

A single sample point is irrelevant. Lots of us got away with things that injured or killed people who did the same things.

Too many didn't.

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My point is that a bunch of people online know nothing about an individuals ability to do something.

Individual ability to deal with abnormal situations requiring survival skills is unknown unless they've had a number of out landings, down wind, into small areas, with low turns to avoid obstacles they didn't see until the last second.

Without those data points we have no idea how they'll react in those situations, so they should be following Brian Germain's guidelines based on how fast people tend to learn and pickup skills.

With those data points from only a few hundred skydives, we know that the individual in question has a history of bad judgement which means they should be following the conservative guidelines so they pose a lesser danger to others and themselves.

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Go see your instructors.

You can count the instructors who know a lot about teaching canopy flight on one hand.

You should be taking advice from those people (like Brian Germain) and only favoring your instructors' opinions when it's more conservative.

Your instructors usually won't be the ones that end up in the hospital if you do something stupid.

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A 170 could be within his range. Myself and a number of others at my DZ have been very successful on canopies of this size with low jump numbers. It is possible but a local instructor needs to make that call.

I know plenty of people who've been quite successful at drunk driving (at least until they lost their licenses) but wouldn't choose to follow their lead.

[hackish 8]

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Go see your instructors.

You can count the instructors who know a lot about teaching canopy flight on one hand.

You should be taking advice from those people (like Brian Germain) and only favoring your instructors' opinions when it's more conservative.

Your instructors usually won't be the ones that end up in the hospital if you do something stupid.

Based on your opinion instructors advice is not reliable enough to listen to. Different people come from different backgrounds. Some people pick things up quicker than others some people do not. This is why I advocate going to see some instructors and see what their opinions are after having evaluated your skills.

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A 170 could be within his range. Myself and a number of others at my DZ have been very successful on canopies of this size with low jump numbers. It is possible but a local instructor needs to make that call.

I know plenty of people who've been quite successful at drunk driving (at least until they lost their licenses) but wouldn't choose to follow their lead.

I think someone with 40 jumps on a 170 is a huge stretch from a drunk driver. Fine, 40 jump wonder on a 120 that's a stretch.

Personally I think it's like a 14 year-old with a drivers license. I believe in France you need to be 19 to drive so you could imagine their response when they hear about it. That's crazy they're all going to die! Oh wait, some places you can get the first driver's license at 14 and all the kids aren't all killing themselves.

Similarly some dropzones and countries in general are a little more aggressive on their canopy sizing. Like everything it has to be appropriate and with the proper education. When you look at the accident statistics it can't all be wrong either.

For the record I took the Scott Miller course at 40 jumps with my sabre2 170 and the instructor did okay it.

I just feel that some instructors evaluating you in person are better than people on the interweb who have never seen you and won't be in the hosital with you either.

-Michael

[MarkM 0]

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I think you've entirely missed the point. Lots of people online told me how I'd die under that canopy. All the instructors who watched said ok it's aggressive, be careful but it's not outside your capibilities.

Online we tend to go with the trends. So the advice you're going to see here is based on someone being "average" and the WL recommendations are pretty well known and they do a pretty good job. So they get quoted and people get heavily discouraged from going above them.

And since most people are average(despite them thinking otherwise), it's generally good advice.

There's also another aspect, what's the big rush? Why does this person need to be on a 170 over a 190? Wind penetration? He shouldn't be jumping in winds high enough where this is an issue. More performance? He doesn't have the skill to notice it. Doesn't want to downsize again in 100 jumps? If you buy used/sell when you're done, it costs like nothing to use a canopy for 100 jumps.

Same thing with a container fit. Buy a larger used container with room for a bigger main(and bigger reserve). Beat the crap out of it, sell it when you're done and not putting grass stains on your gear anymore. Then you can buy nice, small and shiny.

I'd really like to hear the "pro" side to this person being at a 1.2 WL with so few jumps.

[brettski74 0]

Michael,

I don't think people are trying to beat you up over your specific canopy progression - well at least some of them aren't. It may have been aggressive. It may have worked out ok for you so far and may continue to work out well. That's great. The message you're giving about talking to an instructor rather than learning to skydive on the intertubes is also great.

What's not great is the message you're giving about what is an appropriate wing loading or canopy size for a jumper with limited experience and almost no currency. The problem is that many people will not read/hear your disclaimer about how that may not be a great idea for many people. All they will read that some guy jumped this canopy at this number of jumps and it worked out great and that's a message that gives many coaches and instructors cause for concern.

[Nataly 38]

Always take advice with a bit of caution.. I'm a small jumper and as such everyone told me a 135 should be fine (my exit weight is about 120).. So on the face of things, sounds like an ok ratio, no? WELL.. At something like 20 or 30 jumps I bought a Sabre 135.. The smallest I had jumped before this was a 170.. The lines are SIGNIFICANTLY shorter on a 135, making it much more responsive - even on a docile Sabre..

I never hurt myself, but that doesn't mean that canopy was appropriate for me at the time.. I jump the same gear years later and when I haven't jumped for a while it still manages to seem faster than I remember it..

The fact that you're asking the question at all makes me think you know it's too small but you're trying to convince yourself otherwise.. There's nothing wrong with being cautious and downsizing when you're ready. Get a rig which will allow you to just swap the main once you want to downsize.

"There is no problem so bad you can't make it worse."
- Chris Hadfield
« Sors le martinet et flagelle toi indigne contrôleuse de gestion. »
- my boss

[Chubba 0]

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There's also another aspect, what's the big rush? Why does this person need to be on a 170 over a 190? Wind penetration? He shouldn't be jumping in winds high enough where this is an issue. More performance? He doesn't have the skill to notice it. Doesn't want to downsize again in 100 jumps? If you buy used/sell when you're done, it costs like nothing to use a canopy for 100 jumps.

Right on, it's all just a different mindset.

I jump a Sabre2 170 @ 0.95 and I'm very happy, going to keep it till 300+ jumps, learn wingsuit on it, learn camera on it. I have plenty of fun jumping it and I feel comfortable knowing I can stand it up 100% of times in ideal conditions and WHEN (haven't yet) I get into that extremely ugly situation, it's going to treat me well.

Sure it's sucky in high winds, but I'm young (23) and want another 30-40 years of jumping ahead of me... so I just sit down when it's over over 20 knots pushing 25, chat with the blokes and jump again another day.

I just wish everyone would stand up and say NO, a wingloading of 1.2 is NOT acceptable for a person with 18 jumps essentially... don't pussyfoot around the issue, there is absolutely no reason why he can't jump a 190 or 210.