Forums: Skydiving: Gear and Rigging:
(dis)advantages: air-locked vs cross-braced

 


wlie  (D 27320)

Aug 21, 2002, 2:48 AM
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(dis)advantages: air-locked vs cross-braced Can't Post

Which do you prefer? Why?

I'm getting mixed inputs. Please set me straight.


Premier billvon  (D 16479)
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Aug 21, 2002, 11:36 AM
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Re: [wlie] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

Both are a bit more stable in turbulence, although airlocks especially do not measure up to the hype about them (i.e. airlocks do not make a canopy turbulence resistant.) Cross braces do more to maintain the canopy's shape during normal flight, so a more efficient airfoil is possible. At lower loadings that effect is not as significant.


Premier SkymonkeyONE  (D 12501)

Aug 21, 2002, 11:52 AM
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Re: [wlie] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

Well, the question here is "what do I want my canopy to do?"

I have owned both airlocked and crossbraced mains and would have to say that I preferred the openings of the airlocked canopy I had (a Vengeance 97) over the openings of my crossbraced VX 74. For my purpose though, the VX was the preferred swooping main of the two. I still like crossbraces and have one in my spare rig right now, but I don't think I would jump it with my wingsuit on due to the increased risk of a spinning opening as compared to my competition main.

Does this mean I think everyone should choose a crossbrace over an airlocked main? Absolutely not. I wouldn't consider buying a crossbrace if I planned on loading it under about 2.0. Still, that's just me, and I know people that have fairly lightly loaded crossbraced tri-cells and swear they think it's worth it. The main drawback to "larger" crossbraces is the fact that they pack so big. Also, if you are not loading them fairly heavy and flying them hard, you are not going to truly be exploiting the canopy to it's designed limits. Do you have to hook a crossbrace or an airlock? No again; they land fine straight in, but if that's your bag, you might as well have saved some cash and bought a more "traditional" eliptical.

Just my opinion.

Chuckie
Chuck


Samurai136  (D 26609)

Aug 21, 2002, 1:28 PM
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Re: [wlie] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

If your current jump info is correct (131jumps on 170 Diablo) a move to the largest X-braced (120 Velocity) would add .5 to what ever your current wing-loading is. Many canopy pilots I know would consider that to big a move in canopy size at any experience level.

X-bracing makes the top and bottom skin of the canopy flatter and the wing less deformed than non-cross-braced canopys. This makes the wing more efficent because it has less drag thus a longer swoop in skilled hands.

Air-locks are a 1-way valve that keep air in the canopy. Nothing is turbulence proof. Skydive Iowa is a small DZ w/ a very close treeline south of the landing area. When the wind is out of the south I am glad I have my airlocks. If you hit turbulence at flare altitude, 5-10' agl, you'll probably end up w/ grass stains on your jumpsuit.

I would reccommend at least 300 jumps before moving to an elliptical airlocked canopy in the 136- 150 sq ft range. I love my 136 Samurai so much I'm getting a second one to jump turn around loads. It has a great perfomance range! I can chase my friends around under canopy for a few pins, always make it in from a long spot to the main landing area, and it swoops well. I have gotten good 30meter swoops off 90 degree fron t riser onto final.


Airlocks won't make the wing more efficent than x-bracing but it would be a good transitional canopy to learn swooping on if you plan on some day jumping a x-braced.


Ken


wlie  (D 27320)

Aug 21, 2002, 5:09 PM
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Re: [Samurai136] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

Sorry if I left any impression that I was shopping for something I'm not yet ready. I'm sticking with my Diablo 170 as I still consider it an advanced canopy.

Before settling on my first and current gear, besides choosing a reasonable wingload and "square vs elliptical", "7-cell vs 9-cell" was one more thing to consider. Like about a year ago, I thought anyone jumping a Stiletto was a hotshot. Didn't matter what size it was.

All of a sudden these guys are jumping tiny x-braces. You can imagine someone gear shopping consider "x-braced vs air-locked" because of what the hotshots they admire are now jumping. Little is said about their characteristics, so I hope we can have a better understanding.

I was left with the impression that the idea behind x-braced or air-lock is to keep it's shape or at least keep it rigid. I guess x-brace canopies were designed to be highly loaded and flown fast. And this is why I see more and more swoopers jumping x-braced canopies. I thought perhaps air-locks aren't as popular because you need not fly it as fast or maybe it can't fly as fast to cover more ground.

Companies like PD, Icarus, and Precision are aggressively marketing their x-braced line, while Big Air Sports I've noticed exclusively offers air-locks (I guess they invented it?).

About a year ago I remember Aerodyne running full page ads for Triathlons and Diablos, and PD was doing the same with their Sabre2. But that was still 7-cell vs 9-cell, and square vs elliptical. I wonder if "The New Aerodyne - The Renaissance Continues" ads, following the "anticipation and suspense" tactic like Precision's Ground Zero campaign, might yield yet another x-braced or air-locked to spice our choices.


Premier PhreeZone  (D License)
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Aug 21, 2002, 5:49 PM
Post #6 of 8 (853 views)
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Re: [wlie] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

The new Aerodye product line will be mainly 9 cell canopies from all accounts that I've heard. Crossbraced is a small.. but ever growing niche of the over all market.

I doubt you will see mainy companies use Airlocks because you have to pay a licensing fee for use of Brian Germains design since he patented it. Big Air makes some of the nicest canopies I've ever jumped. If the Airlocks work or not I could care less... they fly nice and thats where it matters for me.

Remember... buy a canopy because you like the way it flys.. not because you think its got some thing that lets you jump in questionable conditions.


jerm  (D 23994)

Aug 22, 2002, 3:26 PM
Post #7 of 8 (751 views)
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Re: [wlie] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

Airlocks and crossbraces aren't really competing technologies. Airlocks are designed to keep air in the canopy, while crossbracing is designed to eliminate wing deformation under high-loads (in a nutshell).

While some claim that airlocks have somewhat of a croassbracing effect on the nose of the wing, they don't seem to be a replacement -- case in point: Mike swanson is jumping a prototype BigAir canopy that is both airlocked and crossbraced...

It's more a question of do i think i need crossbracing for the way i want to fly, and do i like the way an airlocked canopy flies... one day you may not have to chose between the two.


(This post was edited by jerm on Aug 22, 2002, 3:27 PM)


Engovatov

Aug 22, 2002, 8:23 PM
Post #8 of 8 (730 views)
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Re: [Samurai136] (dis)advantages: air-locked vs cross-braced [In reply to] Can't Post

In reply to:
If your current jump info is correct (131jumps on 170 Diablo) a move to the largest X-braced (120 Velocity) would add .5 to what ever your current wing-loading is.

Mmm..
150 exit lb on 170, moving to 120 is a jump from 0.88 to 1.25 a jump of 0.37
230 exit
1.35 to 1.91 a jump of 0.56

Your math is a tiny bit off..Tongue
But the conclusion is not..



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