Forums: Skydiving: Gear and Rigging:
Wing loading performance change

 


katzas

Sep 23, 2013, 8:48 PM
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Wing loading performance change Can't Post

OK--I am looking at buying either a used or new main, reserve, harness and container. Buying new is no problem--other than the sticker shock. Buying used--total new ball game. Harness and container size for my body AND for the canopies it could contain--a real jigsaw puzzle. My question is this. All things being equal (jumper weight, canopy type (i.e. Pilot) wind conditions, drop zone location) can you really, honestly say that a 210 sq ft canopy will behave significantly differently than a 190? The calculations of comparative wing loading given a 210 lb skydiver under both those canopies yield the following numbers. 210 canopy-- 1.0. 190 canopy--1.1. That's one tenth difference. Anybody have any real life experience with this?


mattjw916  (D License)

Sep 23, 2013, 9:38 PM
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

smaller canopies are relatively faster... the effect is more pronounced the smaller you go

w/l is just a guide, a reference point... it's not the only value to consider when choosing a canopy

the type of wing, materials, cell count, lines, etc all contribute to a wing's perceived aggressiveness


nigel99  (D 1)

Sep 24, 2013, 12:29 AM
Post #3 of 15 (3583 views)
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

katzas wrote:
OK--I am looking at buying either a used or new main, reserve, harness and container. Buying new is no problem--other than the sticker shock. Buying used--total new ball game. Harness and container size for my body AND for the canopies it could contain--a real jigsaw puzzle. My question is this. All things being equal (jumper weight, canopy type (i.e. Pilot) wind conditions, drop zone location) can you really, honestly say that a 210 sq ft canopy will behave significantly differently than a 190? The calculations of comparative wing loading given a 210 lb skydiver under both those canopies yield the following numbers. 210 canopy-- 1.0. 190 canopy--1.1. That's one tenth difference. Anybody have any real life experience with this?

What I have found is that a huge amount depends on your currency and genuine proficiency (not how good you think you are, but how good you really are).

Even though people say it is less pronounced at the lower wingloadings and this is true, it still makes a difference. If you are jumping every weekend and doing a few jumps then it is far less of a consideration than if you are jumping once a month.

Some people 'get' canopy flight and others don't. If you get it, then I would say you are consistently landing within 10m of a target safely on your jumps. No excuses, no blaming traffic or the spot, but consistently within an accuracy circle designated landing area.

But so many factors come into play that in reality, your best bet is to get the input of the most conservative and grumpy instructor at your dz.


shropshire  (C License)

Sep 24, 2013, 12:30 AM
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

Wing Loading (Canopy size) is only 1 part of the equation too..

For example a Katana 150 and a Sabre_1 150 will have the same wing loading - but are way different beasts.

Size isn't everything ... contrary to popular opinionTongue


grue  (D License)

Sep 24, 2013, 1:38 AM
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

I in fact do have experience with this. However, before I get into that: Your wingloading is determined WITH GEAR WEIGHT. 210lb jumper with a rig with a 210sqft main and similarly sized reserve is going to have an exit weight closer to 240lbs, meaning you're looking at a 1.14 vs a 1.26 with those numbers. Depending on your jump numbers, that could be quite aggressive.

My first canopy that I bought at 44 jumps was a Precision Aerodynamics Fusion 210 that I was loading at 1.2something. About a hundred jumps later I blew it up and downsized to a Fusion 190 at about a 1.35 wingload (at under 150 jumps Pirate ), thereby doing the exact change you're talking about: Same jumper, same model canopy, new size of canopy.

It was definitely quicker, and more responsive. Everything happened more quickly: It flew faster at full glide, it lost more altitude in turns, and approaches seemed a bit more spicy :) It became substantially more sensitive to harness input as well. I couldn't swoop with harness input alone, but I could sure as hell make course changes. All of the above intensified when I put on weight, and I was eventually loading it at around a 1.5 before I went on a big diet (down below a 1.3 now)

I personally would NOT recommend following my path as it was too aggressive by most standards. I got away with it, but that doesn't mean everyone would.


(This post was edited by grue on Sep 24, 2013, 1:41 AM)


DivingWombat  (B License)

Sep 24, 2013, 1:44 AM
Post #6 of 15 (3540 views)
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

katzas wrote:
OK--I am looking at buying either a used or new main, reserve, harness and container. Buying new is no problem--other than the sticker shock. Buying used--total new ball game. Harness and container size for my body AND for the canopies it could contain--a real jigsaw puzzle. My question is this. All things being equal (jumper weight, canopy type (i.e. Pilot) wind conditions, drop zone location) can you really, honestly say that a 210 sq ft canopy will behave significantly differently than a 190? The calculations of comparative wing loading given a 210 lb skydiver under both those canopies yield the following numbers. 210 canopy-- 1.0. 190 canopy--1.1. That's one tenth difference. Anybody have any real life experience with this?

While waiting for my rig, I put about 20 jumps on a Pilot 210. It was fun and easy.

When I got my own rig with the Pilot 188, things changed a bit. I have to add that I was jumping it at a DZ which is 1500 feet above the one I jumped the 210.

To say it in few words...one size smaller can be a big difference.
I think a WL of 1.0 - 1.1 is no big deal for most beginners. But in the range of 1.2 to 1.3/1.4 it can get pretty fast and dangerous.

Jump it and get your own picture.

"The calculations of comparative wing loading given a 210 lb skydiver " -->Skydiver only or comletely geared up???


nigel99  (D 1)

Sep 24, 2013, 3:47 AM
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Re: [shropshire] Wing loading performance change [In reply to] Can't Post

shropshire wrote:
Wing Loading (Canopy size) is only 1 part of the equation too..

For example a Katana 150 and a Sabre_1 150 will have the same wing loading - but are way different beasts.

Size isn't everything ... contrary to popular opinionTongue

So your wife believes small and fast is better?Shocked

PS the OP covered the all else being equal aspectTongue


jurgencamps  (D License)

Sep 25, 2013, 1:55 AM
Post #8 of 15 (3043 views)
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

Also a 190 canopy A can be smaller or bigger then a 190 canopy B.
For ex. a tempo 150 is smaller then a PDR 143.


wolfriverjoe  (A 50013)

Sep 28, 2013, 4:11 PM
Post #9 of 15 (2687 views)
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

katzas wrote:
... All things being equal (jumper weight, canopy type (i.e. Pilot) wind conditions, drop zone location) can you really, honestly say that a 210 sq ft canopy will behave significantly differently than a 190? The calculations of comparative wing loading given a 210 lb skydiver under both those canopies yield the following numbers. 210 canopy-- 1.0. 190 canopy--1.1. That's one tenth difference. Anybody have any real life experience with this?

First off, is the "210 lb skydiver" exit weight, street clothes weight or stepping out of the shower weight?

Just to be clear, the weight used in calculating wingloading is exit weight. How much you weigh as you step out of the plane. Including all the gear, clothes, shoes and pocket junk.

But to answer your question: It will be noticeable, but not significantly different.

I went from a Triathlon 190, loaded almost exactly at 1:1, to a 170 Sabre2 loaded around 1.15:1.

Definitely faster. Faster turning, faster approach speed, faster landing speed, more responsive flare, more responsive to toggle and riser input.

It wasn't "Holy Shit!!!! This thing is fast" But it was a noticeable difference.
And part of that difference was going from a nearly square 7 cell to a slightly elliptical 9 cell.

But I never felt like I was in over my head with the change. I did most of the items on the downsizing checklists (BillVon's or Brian Germain's) fairly quickly. I'm very comfortable under it, and plan on staying with it for a while.


DocPop  (C License)

Sep 29, 2013, 11:04 AM
Post #10 of 15 (2558 views)
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Re: [wolfriverjoe] Wing loading performance change [In reply to] Can't Post

wolfriverjoe wrote:

I went from a Triathlon 190, loaded almost exactly at 1:1, to a 170 Sabre2 loaded around 1.15:1.

I'd say most of the difference you're feeling there is due to change of model/planform.

I went from a Sabre2 190 to a Sabre2 170 and didn't notice much of a difference. When I subsequently went to a Sabre2 150 there was much more of a noticeable change.

With bigger canopies, a one size change is unlikely to produce dramatic changes in performance, all other things being equal.

I can't comment on the OPs question as the biggest canopy I have ever jumped is a 200.


Sky_doggy  (C 41295)

Sep 30, 2013, 8:26 PM
Post #11 of 15 (2333 views)
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Re: [DocPop] Wing loading performance change [In reply to] Can't Post

I have a similar profile to yours. I am 195 out the door and I have recently down sized from a Pilot 188 to a Pilot 168.

The change wasn't dramatic, a little more responsive, a bit faster and more flare.


wolfriverjoe  (A 50013)

Oct 2, 2013, 6:27 PM
Post #12 of 15 (2163 views)
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Re: [DocPop] Wing loading performance change [In reply to] Can't Post

DocPop wrote:
wolfriverjoe wrote:

I went from a Triathlon 190, loaded almost exactly at 1:1, to a 170 Sabre2 loaded around 1.15:1.

I'd say most of the difference you're feeling there is due to change of model/planform...

That may be. I don't know.

It would be fun to try a Tri 170 or a Sabre2 190 to see how much the apparent difference is due to size and how much to planform.

My point was (and is) that even changing both size and canopy model wasn't a dramatic or huge change.


DocPop  (C License)

Oct 3, 2013, 7:37 AM
Post #13 of 15 (2037 views)
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Re: [wolfriverjoe] Wing loading performance change [In reply to] Can't Post

Agreed.


riggerrob  (D 14840)

Oct 3, 2013, 8:49 PM
Post #14 of 15 (1870 views)
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Re: [katzas] Wing loading performance change [In reply to] Can't Post

Did you read my article entitled "Wing Loading" published in Canadian Parachutist magazine in 1983?


katzas

Nov 8, 2013, 3:15 PM
Post #15 of 15 (1451 views)
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Re: [nigel99] Wing loading performance change [In reply to] Can't Post

Thanks for the reply. I did say that "all things being equal" which means that if I fly a Pilot 230 vs a Pilot 210 being the only difference. My first ram air canopy was a Wizard 7 cell, 260 sq ft. I chose a larger canopy because I like soft landings. However, that canopy would stall predictably, recover predictably and spin me around while losing altitude quite nicely.
Toggle pressure was light and the thing would go where I pointed it. I never had an off heading opening--and it never spanked me. Getting back into the sport now it seems that there are few 7 cells around and some of the 9 cells are downright scary. The gear I rented included Navigators of diferent sizes--from a 280 (a REAL truck) to a 210--which was more responsive--but they both set me down gently and on my feet. I weigh 220 ish out the door. The 280 was chosen for me by my first re-currency instructor--and I guess if I was him I would have done the same thing--being cautious.

I guess my question was can 20 sq ft at those sizes really make that much difference. Thanks to all who answered.



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