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melk

Packing nuances

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Being around enough jumpers/packers/riggers eventually you start to notice that there are tons of different packing nuances.

I'm curious about a few things i have seen other ppl do, but without much explanation behind it. To be clear, I'm not criticizing any of these things or lack thereof, just trying to gather opinions (and preferably information).

1) Roll the nose - why do people do this? I have heard ppl claim it makes their opening "better", but why/how/does it actually make an opening better?

2) Roll the dbag down toward the bottom of the container (so the lines are down by the BOC and the bridle grommet is up by the reserve tray) - is there any benefit to doing this on a sport rig? I have a wings and i leave the dbag in with the lines toward the back of the container which seems the most logical to me, but I often see people roll it down toward the bottom and have yet to get a reason why

3) Line excess - how much line should you leave unstowed? I tend to leave roughly 12-24 inches, but just today I had a rigger tell me to make one more stow because too much excess can cause line twists, but another rigger has told me the exact opposite - that not enough excess can cause line twists. Since i was packing one of the DZs rigs and not my own, I did it his way, but i would really love to know if one way is more right. Like I said, this is actually a point I have been told differently by different riggers- kindve like double vs single stows ;)

4) Flaking - often times (we all have seen and probably done this) ppl will flake their canopy and then throw it onto the ground not-so-gently so that it fluffs up. My question is does that really "ruin" the flaking and should one make an effort to lay it down as gentle as possible?

i notice ppl with their own packing quirks and I'm trying to determine where all the variation comes from so I can keep the good, ditch the bad and become a more effective packer.

Cheers!

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melk

Being around enough jumpers/packers/riggers eventually you start to notice that there are tons of different packing nuances.

I'm curious about a few things i have seen other ppl do, but without much explanation behind it. To be clear, I'm not criticizing any of these things or lack thereof, just trying to gather opinions (and preferably information).

1) Roll the nose - why do people do this? I have heard ppl claim it makes their opening "better", but why/how/does it actually make an opening better?

2) Roll the dbag down toward the bottom of the container (so the lines are down by the BOC and the bridle grommet is up by the reserve tray) - is there any benefit to doing this on a sport rig? I have a wings and i leave the dbag in with the lines toward the back of the container which seems the most logical to me, but I often see people roll it down toward the bottom and have yet to get a reason why

3) Line excess - how much line should you leave unstowed? I tend to leave roughly 12-24 inches, but just today I had a rigger tell me to make one more stow because too much excess can cause line twists, but another rigger has told me the exact opposite - that not enough excess can cause line twists. Since i was packing one of the DZs rigs and not my own, I did it his way, but i would really love to know if one way is more right. Like I said, this is actually a point I have been told differently by different riggers- kindve like double vs single stows ;)

4) Flaking - often times (we all have seen and probably done this) ppl will flake their canopy and then throw it onto the ground not-so-gently so that it fluffs up. My question is does that really "ruin" the flaking and should one make an effort to lay it down as gentle as possible?

i notice ppl with their own packing quirks and I'm trying to determine where all the variation comes from so I can keep the good, ditch the bad and become a more effective packer.

Cheers!



1. Rolling the nose is to help slow down the openings. It delays the process of air filling into the nose and inflating the canopy. If you have to roll the nose to get good openings, you probably should get a better canopy. Pretty much any modern canopy opens perfectly fine without rolling the nose.

2. I dont know what the claimed reason for rotating the bag up is. I think the theory is that it allows the bag to be pulled straight up and off your back instead of having to turn 90 degrees. Anyway, you can bet manufacturers have tested that method many times and if it was the ideal way to do things that is what they would recommenced. But I dont know of any manufacturer that recommends that process. Go with the process that the manual shows. No one knows more about your gear than the people who make it.

3. You should leave 24 - 30" of excess line. Leaving too little can cause line twists because if you leave too little the bag will not have accelerated sufficiently before pulling off the first line stow. The end result is it's more likely the linestow will rock the bag off to one side causing a twist. This is irrelevant if you have a semi-stowless bag as a semi-stowless bag is basically just a controlled version of coiling your entire lineset into the pack tray.

I know someone who figure-eights his entire lines into the tray and only uses the locking stows. That's excessive IMO, but he claims it works. If you go too overboard (e.g. more than 3-4 feet) though it's possible the lines could blow out of your tray on opening and get stuck on you, which would be bad.

4. You should make an effort to lay the canopy down gently. Honestly, you probably mess up the flaking a bit when you lay on it anyway, but the less we can do to mess it up the better. Will throwing it down cause a malfunction? No, but over the course of time, continuously throwing it down ever and over instead of being genital about it could eventually lead to getting a lineover over the course of hundreds or thousands of pack jobs. The greater concern is ensuring the slider stays in place. If you throw it down the slider could move, and if that happens you could get a hard opening.

I know people who dont flake their canopy at all. They just do the slider, wrap the top skin around and then start their S folds. The canopy still opens, but eventually that lax attitude might lead them to getting a chop sooner or latter.

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I have! (Specifically the packing part, not every part). I might not have been clear, even though the examples I gave were regarding my own gear, my focus was more about when I'm packing other people's gear. In terms of my own gear I guess I'm guilty of primarily taking stock in what my riggers have suggested I do. I have not read the manual for every container. I'm also one of those "full picture" type of people, so knowing the why behind things helps me understand the process better. Example, knowing why people roll the nose, not just that some do and some don't. I have not ever rolled the nose, largely due to the fact that I was never taught to specifically.

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Let's keep it to your own container. (When you're packing for others, you should better be double sure you know what you're doing.)

I appreciate you're trying to find knowledge and to understand "why". What I don't get is that you change the procedure before understanding the reasons behind it, that is a dangerous attitude in this sport.

The manual is clear: "Lift the Main Deployment Bag over the container without twisting the lines and place into the Main Container with the lines towards the Bottom Flap of the container and the Bridle towards the Reserve container."
You read this, and you still go against the manufacturer because you think the other way around seems more logical, or nobody has given you a good reason yet why it is done this way? I can't imagine a rigger has suggested to you it is OK to put the bag upside down in the container.
Any rigger worth his salt should be able to explain to you why the D-bag is in the container this way. Go ask.

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Cloggy


I appreciate you're trying to find knowledge and to understand "why". What I don't get is that you change the procedure before understanding the reasons behind it, that is a dangerous attitude in this sport.



C'mon, he isn't just changing things. Ok, except for 'standing the bag up' in the tray. And we don't know why he did that -- It might have been recommended to him.

Lots of things are old or debatable or simplified in manuals without showing valid alternatives.

Sometimes skydivers change things for the better. Sometimes they change things to a valid alternative. (e.g., Does everyone make sure they fold their BOC as listed in their own rig's manual? No. There are a variety of valid ways and it isn't like a Javelin pilot chute pack job will kill you if used in a Vector III. And yes I checked, they are different. ) Sometimes skydivers change things to be more appropriate to a particular discipline (e.g, wingsuiting). Sometimes they change things... and just following the manual would have been better.

What does a newbie do if experienced riggers and packers tell him different things?? He specifically said he is coming here to better sort out what people are saying. Asking questions is a good thing, a good attitude in the sport.

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No, I put the dbag in with the lines facing the back (not bottom) bc a rigger worth his salt HAS said it's acceptable. If you roll the bag to go in, then, obviously it seems it would roll on its way back out...I assure you I would never just carelessly decide to pack however I "want" bc what I want to do is survive for as long as possible. I'm not sure what you mean as upside down though, this isn't upside than at all.

Also, I do ask lots of questions when packing new-to-me containers. The importance of it is not lost on me.

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Sorry melk and Peter, my bad and my apologies for total misunderstanding and confusion on my side :$
Got thrown off the track by what is back, bottom, front, up etc. and thought you were talking about putting the bridle attachment against the bottom flap and the lines against the reserve container. Hence upside down...

So I really apologize for messing up your thread and for thinking you were making it up on the go... nothing wrong with your attitude, au contraire.
(and I give myself a virtual kick in the behind B|)

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No biggie. I just like to stand up for newbies asking questions, even if their questions sound dumb to us. (As long as they don't show too much know-it-all attitude.)

And we don't exactly have a consistent system of directions in skydiving, relative to a rig.

@ melk:
Historically canopies tended to be bigger than now, so we didn't normally have main d-bags that were as short (bridle to flap) as they were thick. So the standard was what we have now, bridle exiting towards the reserve container.

Only with 'squarer' bags did it make more sense to start
experimenting with 'standing the bag up' rather than 'rotating it down 90 degrees' to go into the container.

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melk

I have a wings and i leave the dbag in with the lines toward the back of the container which seems the most logical to me, but I often see people roll it down toward the bottom and have yet to get a reason why



The best reason I was ever given is that on deployment the PC twists the bag into the upright position, breaking the friction of the bag vs container, then begins lifting the bag out of the pack tray. If the bag starts out in an up right position the PC has to break that friction and lift the bag in 1 motion which is obviously more effort for the PC (think shearing forces vs pealing forces). Sure people do it, and sure it works, but it can cause weird deployments in overly tight containers.

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Westerly

I know someone who figure-eights his entire lines into the tray and only uses the locking stows. That's excessive IMO, but he claims it works. If you go too overboard (e.g. more than 3-4 feet) though it's possible the lines could blow out of your tray on opening and get stuck on you, which would be bad.



Do not do this. The danger is not that the lines "blow out" of your pack tray. What happens is that your side flaps blow into your pack tray and tangle with the coiled up lines. Lines half hitching around side flaps have resulted in fatalities. So again, do not do this, use some form of line control.

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Great questions and good on you for asking them.

1- the idea is that it slows the opening by preventing the canopy from inflating until after the nose unrolls. Debatable if it works or causes off heading openings. Problem is unrolled noses don’t cause hard openings. I believe most hard openings are caused by either not keeping the slider against the slider stops during packing or going too fast when deploying.

2- you want the grommet towards the reserve container. This help to stage the opening process.

3- 18-24 inches. Why not more or less? If you leave less, the lines can hang up on the reserve container on the side that has to wrap around to the bag. This can cause the bag to rotate during deployment. More and you begin to,increase the risk of a line snagging a flap or helmet, or whatever.

Semi stowless bags allow you to stow all the limes and do not cause the bag to spin on deployment. They are also easier and faster to pack. What’s not to like?

4- laying the canopy down gently is more about keeping the control lines from getting in front of the nose. Control lines in front of the nose causes line overs.

Keep asking questions. If someone doesn’t give you the reasoning behind their answer, ask “why?”. Compare the ‘whys’ and decide for yourself. Often, two different answers can be correct, but one is better for you or your gear.

Derek V

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Don't basers use nose rolling for on heading openings? They roll 3 cells left and 3 right and expose the middle one. It is actually sticking out so the air hits it before all other cells.

I always thought that was the main reason for rolling, not slowing down the deployment. Rolling or pushing the nose inside the pack job has the same effect regarding the slowing down process. The only difference is with rolling u loose 1 minute while with pushing you loose 3 seconds.

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Quote

Don't basers use nose rolling for on heading openings?



I didn’t when I was BASE jumping. The center cell was wide open with 3 cells on each side of the center cell.

\\\V///

Is the best I can explain it. Same way reserves are packed. You want a nose first inflation for on-heading performance and to help prevent a line over. If the tail deploys first, the nose can catch a control line, creating a line over. Definitely no rolling of the nose.

I don’t roll or stuff the nose when packing a main.

Derek V

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Something else to consider when leaving line between the links and the first (last?) stow; reserve container length and riser length will both have in impact on the ‘right’ amount to leave.

Basically, leave as little as possible without causing the lines to hang up on the reserve container during deployment.

Derek V

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I rolled the nose on my sabre1 to keep it from opening so hard. It seems to stand me up first then open firmly in about 450 feet verses a semi-hard opening in one motion to the point of my feet being eye level in front of me for about 200 feet. I do have a pocket slider for it as well.

Rolling the nose on my sabre2 is unnecessary. The nose opening are smaller and doesn't fill as quickly and it opens between 6-800 feet

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ChrisHoward

***I have a wings and i leave the dbag in with the lines toward the back of the container which seems the most logical to me, but I often see people roll it down toward the bottom and have yet to get a reason why



The best reason I was ever given is that on deployment the PC twists the bag into the upright position, breaking the friction of the bag vs container, then begins lifting the bag out of the pack tray. If the bag starts out in an up right position the PC has to break that friction and lift the bag in 1 motion which is obviously more effort for the PC (think shearing forces vs pealing forces). Sure people do it, and sure it works, but it can cause weird deployments in overly tight containers.

I see what you mean Chris, but wouldn't leverage be the major factor? When pulling straight out the pilot chute will have to overcome friction on both sides of the bag, when pivoting out only on one side. See attached diagram, assuming friction on the sides of the d-bag is the same in both cases.

Or is that too simplistic a thought, when considering the deformability and geometry of d-bag and container?
It shouldn't be too hard to measure the difference with a spring balance.

LiftDbag.JPG

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Cloggy,

The idea is that the pilot chute has leverage on the grommet side of the bag. It is similar to why a shrivel flap is used with velcro BASE rigs (shear vs. straight pull). As was mentioned earlier, the main d-bags of rigs made 10-30 years ago were more rectangular and were designed to be rotated into place to fit the container. Back when canopies where huge, pilot chutes sometimes struggled to get the bag off the jumper's back. This was especially problematic when ripcords and springloaded PC's were in vogue, as the PC tended to bounce around in the jumper's burble before launching. AFFI's occasionally see this today: usually it involves a small-ish jumper, huge student rig, inappropriate PC size and it happens on a Cat A or B jump where the PC is struggling to find clean air above 3 jumpers flying in close proximity.

Personally-I prefer (and teach) to roll the grommet down into place at the bottom of the reserve container because (if done properly) it forces excess line AWAY from the bottom corners of the reserve tray, helps to put good tension on the main risers routed over the shoulder and improves your ability to force the canopy into the bottom of the main tray. This ensures better distribution, easier closure and improves the aesthetics of the packjob.

All that being said; some of the newer rigs are being designed to have the bag placed grommet side towards the flaps and lines against the jumpers back. An example of this is the Sunpath Military Javelin. When it was originally designed it was deployed with a springloaded PC. The bag was pretty square, it made sense to reinforce the bottom of the bag as a soft "kick plate" and isolate the bridle, mesh and coil spring from the lines. Many of these rigs have been modified to use throw out PC's, but the rig is still packed with the lines down.

Cheers,

-Harry
"Sometimes you eat the bar,
and well-sometimes the bar eats you..."

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