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I'm wondering if there is any relationship between wingloading and heading performance. If the same jumper, at the same object, in the same conditions, with the same body position has the choice between a lightly loaded canopy or a (relatively) heavily loaded canopy...which is the smarter choice (as it relates to heading)? Does it matter at all?

Intuition suggests that a more heavily loaded canopy will magnify any mistakes, particularly related to body position. Also a smaller (more heavily loaded) canopy will be more influenced by PC oscillation and wind. Maybe that's my answer right there.

Not sure if anyone has looked into this at all, but surely there are some opinions out there and probably some real-world observations.

Doesn't a smaller (more heavily loaded) canopy open faster that a bigger canopy? So perhaps the canopy would have less time to "search" or turn with PC oscillation and wind.

I think your reasoning is logical, but in the real world I haven't observed much difference to opening heading from variances in wing loading.

That's an interesting thought too. Maybe the quicker inflation can help with heading performance.

That makes me think that maybe a more lightly loaded canopy can be more subject to offheadings as the canopy will open slower and the problem has more time to develop...

Maybe, like everything in BASE (and life), you can just pick a position and then find enough evidence to support it no matter what your original hypothesis.

i doubt it matters. however big or small your canopy, when it leaves the packtray and starts getting to linestretch is where it may possibly rotate. once its chosen its heading, wherever that may be, and gets loaded, thats where a bigger canopy will inflate a minute bit slower but by then it doesnt matter because its already facing the wall.

i doubt there is a difference in time it takes from pin pop to linestretch with different sized canopies, because on lower delays youre basically just falling away from your packjob.

i think AFTER it has chosen its heading right left or otherwise is where a smaller canopy will inflate quicker than a larger one and thus probably wont matter.

am i on the right track with this? probably not because i am an inexperienced idiot, but goddamn am i one handsome, humorous, and CHARMING devil, so it makes up for it

You are on track. What so many people fail to learn before they start BASE are the fundamentals of how the equipment works. Heavy or lightly loaded canopies get to line stretch at the same speed, and essentially you are not connected to your canopy until it is at line stretch. The three things that effect speed to line stretch are; drag (PC size), speed (delay), and line length. Wing loading has nothing to do with it. If your body position is so bad after line stretch that heading is a consistent problem then maybe go back to the DZ and unfuck yourself. $0.02

While most heading issues probably come just after line stretch (low shoulder; head down; etc) I really don't think wing loading has much of anything to do with it. I'm 210 lbs, have been for a long time. I used to jump a 260, then a 280, and now a 308. All would open at the exact same spot from 250 feet. And while there may be some physical support for your theory, there are other forces to consider. Bigger=more nylon=More air forcing the bottom skin open. I've never seen a difference in opening height until a friend of mine made a FOX XS. That does everything fast.

good point, i totally didnt even consider that sometimes everything is perfect on heading until your body position is so fucked that you unevenly load your risers and completely fuck yourself offheading. touche.

and i really do want to see that fox XS in action. as a matter of fact, roomies are gone, and its downstairs unpacked in the living room.............. maybe i should pop a couple xanax, have a few drinks, and go get stupid =)

I know that when you get into the very large canopies, 330s and 354s and shit, the openings become less consistent. But that is more likely due to their volume not the wingloadings.

True. But usually the bigger and more surprising off headings will result before line stretch.

Right, but then that has nothing to do with wingloading. Canopy volume..?sure. But not wingloading since you don't load your wing until the lines are taunt.

That's interesting. So despite the weight difference in the canopies they all opened around the same height?

I'm interested in the opening height variation between canopies of different weights. Considering that many canopies are made of light weight material now I'm thinking they would also be good choices for low freefall.

If your PC has a drag force that is twice the weight of the canopy than the weight of the canopy is no longer increasing the distance the PC travels in order to support the canopy to line stretch (or some shit like that). So at 9 m/s^2 I'm traveling at 20 mph by the end of the first second. My 48" PC drags over 20 lbs (inaccurate spring scale measurement) at 20 mph. So all canopies were at line stretch and bottom skin inflation at the same spot. And from BSI to flying is a silly measurement to me if your brakes are dialed and your slider is down, because it happens so fast. I laugh when folks are truly concerned about it, unless they are playing in the basement heights.

Line Length increases with canopy size,
hence theoretically bigger wings would
take more altitude to get to linestretch.

we're talking inches... maybe two feet from say a 200-280. probably negligible.

i'd also guess that wing loading would have negligible effect on heading due to the small size difference of BASE specific canopies you'd be ranging between. now if you were to look at the difference between a black jack 280 and a velocity 90, i would bet the heading would definitely be worse on the velo.

I think that's it right there. Intuition suggests that a higher w/l will have less consistent headings, however, the difference in w/l options in our world are too small to make a material difference.

Yes but a Velo will search on opening due to the design of the nose not it's wingloading. So it would be a better comparison to just keep loading weights onto a BASE canopy. Like you said though those weight differences will never come into play on a BASE jump.

my experience is that slider up, lighter loading has poorer heading performance than heavier loading. Not noticed a difference slider down.

for me at 80kg, 240>265>285

I think Anne Halliwell did a survey of WL/heading during petronnas about 2001, can't remember what the results were.

The heading is established before wing loading comes into play. Given good body position, wind, and a good pack job, the delay and proper PC, in my opinion, play with the heading more than anything.

Was just pointing out that this comment
is misleading.

Thanks, that's interesting.

I don't think it is

In skydiving with high performance canopies quicker openings are more often on heading.
This is very noticeable when you compare openings on a 103 with a 84 of the same canopy. Smaller canopy takes less time to inflate.
Once you have spanwise inflation, heading tends to stay as it is.
The effect in base canopies is negligible in my experience, as there is not as much variation in size or wingload, most jumpers aim for around the .7 load. Also, slider down with venting means spanwise inflation times are fast no matter the size.
In theory tho, the smaller (thus higher wingload) canopy should have better heading performance in my experience.

However smaller canopy needs more speed to fly i.e. stays longer in stall and as a results starts flying later than bigger canopy.

Base canopies do perform in stall quite good, but as a general thing in my opinion this could be also a factor.

No. They open about the same slider down. While the smaller canopy does have less air volume to intake to get pressurization, the bigger canopy has bigger vents and cell consoles. So it's about the same.