Wing Loading

[ripcord4 0]

I have been following the wing loading discussion here and in another forum for the past day or two. I think we can all agree that a high, aggressive wing loading has the potential to ruin your day by turning you into a grease spot on the ground. All the posts are concerned with wing loadings in excess of 1:1 - let me go the other way - what about wing loadings LESS than 1:1? For example, I have a canopy that I have calculated the WL at .63:1 . I am 175#, the rig (MC-4, 370 sq. ft.) is 50# and I've allowed 10# for all the other stuff. What are the advantages and disadvantages of this low of a WL? Basically, I'm looking for the cost - benefit ratio, so to speak. What should I be concerned about? Any hints, tips or advice (other than not jumping the military rig, please) would be appreciated. Please disregard my jump numbers and license - I am just getting back into the sport after a 20 year layoff - I consider myself a definite "newbie" and need all the help I can get!

[hookncrater 0]

Well, I'm not an instructor but I have jumped canopies loaded 0.73 and here is my take on them:

1. More susceptible to a bad spot since they have less drive into the wind.
2. Very high toggle and riser pressure, i.e. I wouldn't want to do a x-country jump at that loading since your arms would probably be too tired to flare when you made it back.

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when in doubt... hook it!

[billvon 2,426]

There are a few problems with light loadings:

1. At _very_ light loadings (i.e. <.5 to 1) you may see deployment problems

2. You won't have much penetration power in winds

3. You may be more susceptible to turbulence; on the plus side any turbulence-related problems will happen more slowly and you will be in a better position to recover from them.

[caspar 0]

care to expand on "deployment problems??" im trying to think through the physics of all of it and i dont see how there would be a big difference...

"When I read about the evils of drinking, I gave up reading."

[billvon 2,426]

>care to expand on "deployment problems??"

Closed end cells mainly. A larger load on the same parachute will generally cause a harder opening, and this can help inflate end cells. We had a lot of closed end cell problems when we underloaded our larger (11 cell) tandem mains. Nothing bad, just annoying.

[EvilLurker 2]

FYI I jump a PD 9-cell loaded at ~.8:1 and I never get end cell closures, so it stops being a problem somewhere below that loading. Wind penetration is poor, but I don't have a collapsible PC, which would help. I'd describe the toggle pressure at my loading as "moderate".

[billvon 2,426]

>I jump a PD 9-cell loaded at ~.8:1 and I never get end cell
>closures, so it stops being a problem somewhere below that loading.

Yeah, I'm thinking loadings in the .5-.6 area.

[skyyhi 0]

Quote

FYI I jump a PD 9-cell loaded at ~.8:1 and I never get end cell closures, so it stops being a problem somewhere below that loading. Wind penetration is poor, but I don't have a collapsible PC, which would help. I'd describe the toggle pressure at my loading as "moderate".

I was getting end cell closure on my Sabre 210 (wl of .73:1) nearly every jump. . .and very long snivels. . .I now jump much closer to 1:1 and never have this problem.

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Darcy