0
wildernessmedic

Consistent line twists

Recommended Posts

Having consistent line twists with my pack jobs. What could be causing this? My body position is definitely stable before and after deploying. I make sure my D-Bag comes straight down and the lines don't twist when stowing. Stows are neat and tensioned.


Also, when the lines twists aren't so dramatic, my canopy seems to surge down right after inflating like the front risers are being yanked.


Advice? Not sure what i'm doing wrong.

Forgot another question. Confused on the orientation the line stows when putting the packed D bag into the container. Have heard both ways form packers.

Container says important, line stows to bottom. Does that mean the stows should be down on the bottom (ground) with bridle attachment facing straight up and out, or stows facing down as in towards your butt with the bridle attachment up next to your closing loop?

I've been doing it the second way.

Share this post


Link to post
Share on other sites
wildernessmedic

Having consistent line twists with my pack jobs. What could be causing this? My body position is definitely stable before and after deploying. I make sure my D-Bag comes straight down and the lines don't twist when stowing. Stows are neat and tensioned.


Also, when the lines twists aren't so dramatic, my canopy seems to surge down right after inflating like the front risers are being yanked.


Advice? Not sure what i'm doing wrong.

Forgot another question. Confused on the orientation the line stows when putting the packed D bag into the container. Have heard both ways form packers.

Container says important, line stows to bottom. Does that mean the stows should be down on the bottom (ground) with bridle attachment facing straight up and out, or stows facing down as in towards your butt with the bridle attachment up next to your closing loop?

I've been doing it the second way.



If I understand you I'd say the second way, lines down toward the BOC and bridle up by the closing loop near the reserve. I have under 100 pack jobs though so I suggest you get a remedial lesson from a qualified packing instructor or rigger. I think line twists are usually caused by poor body position. Perhaps do a coach jump and get video of your deployment?
"Now, why do witches burn?"
"...because they're made of... wood?"
"Good. So how do you tell whether she is made of wood?"
"Build a bridge out of her."

Share this post


Link to post
Share on other sites
lomcovak

***Having consistent line twists with my pack jobs. What could be causing this? My body position is definitely stable before and after deploying. I make sure my D-Bag comes straight down and the lines don't twist when stowing. Stows are neat and tensioned.


Also, when the lines twists aren't so dramatic, my canopy seems to surge down right after inflating like the front risers are being yanked.


Advice? Not sure what i'm doing wrong.

Forgot another question. Confused on the orientation the line stows when putting the packed D bag into the container. Have heard both ways form packers.

Container says important, line stows to bottom. Does that mean the stows should be down on the bottom (ground) with bridle attachment facing straight up and out, or stows facing down as in towards your butt with the bridle attachment up next to your closing loop?

I've been doing it the second way.



If I understand you I'd say the second way, lines down toward the BOC and bridle up by the closing loop near the reserve. I have under 100 pack jobs though so I suggest you get a remedial lesson from a qualified packing instructor or rigger. I think line twists are usually caused by poor body position. Perhaps do a coach jump and get video of your deployment?
I've asked a couple packers and got varied answers but most said this way so that's what i've been doing. Some packing videos show it the other way though.

I have videos of my deployments and they look fine. I've done tunnel time flying in the pull position messing around turning left and right in it. A lot of the time I will sit in the pull position for a second or two before pitching to make sure my heading isn't changing.

I feel like that's not the problem and suspect it's something else but what do I know.:S It seems more like once the opening process is started its violent and tossing me around and spinning me around more than anything.

Share this post


Link to post
Share on other sites
I've jumped a spectre a few times and that doesn't sound like typical spectre behaviour. I thought they were predictable openers. Is it an old canopy? Is the pilot chute old? I've heard that a tired PC can affect openings. Are the riser covers opening symmetrically? I heard of someone light who's riser flaps stayed closed right down to landing! Is one sticking? Are the openings hard? Just stabbing in the dark really, hopefully someone with more experience will have something to add.
"Now, why do witches burn?"
"...because they're made of... wood?"
"Good. So how do you tell whether she is made of wood?"
"Build a bridge out of her."

Share this post


Link to post
Share on other sites
lomcovak

I've jumped a spectre a few times and that doesn't sound like typical spectre behaviour. I thought they were predictable openers. Is it an old canopy? Is the pilot chute old? I've heard that a tired PC can affect openings. Are the riser covers opening symmetrically? I heard of someone light who's riser flaps stayed closed right down to landing! Is one sticking? Are the openings hard? Just stabbing in the dark really, hopefully someone with more experience will have something to add.



Any ideas are appreciated. Exactly, everyone has told me the Spectre is known for great predictable on heading openings but i've had nothing but the opposite.

The canopy is supposed to only have 400 jumps on it. PC looks pretty old and i've thought about replacing it although my rigger that inspected it said it was fine. Maybe it has something to do with the age.

Riser flaps too maybe? Mine are extremely old and barely stay shut so the possibility of them opening premature is...well I know it has happened. Definitely not staying shut. They are getting replaced right now so I guess i'll find out if that was it when I pick it up.

Share this post


Link to post
Share on other sites
hackish

Best piece of advice I ever got was from an old fart in Deland. He suggested that I spend an entire jump doing practice pulls and making sure I was staying on heading... I'll bet I went a good 200 jumps linetwist free after that...

-Michael



Not sure if you didn't read what I posted or were just adding how helpful it is... Done more than one jump doing that and tunnel time focusing on getting a stable deployment position. Still line twists....

Share this post


Link to post
Share on other sites
I would have a rigger check to make sure your canopy is still in trim. I've never had a specter get more than 2 twist in it and that was entirely my fault. Also give this a try. When you put your D-bag in your container make it so the stows are against your back and the bridal attachment is coming out perpendicular to the packing tray. If you still have line twists then it probably isn't being caused by your container. Meaning it is either the canopy or your body positioning.

Share this post


Link to post
Share on other sites
Maybe you could ask someone else to do 5 pack jobs or so in a row for you (perhaps you could trade or something) to see if it makes a difference? Not that it would give 100% certainty, but if you get consistently good openings on those jumps, then you've most likely narrowed it down to packing technique (or vice versa).

Share this post


Link to post
Share on other sites
Possible simple fix: We had a guy at our DZ who was having a similar problem, video showed perfect body position on opening but bag twisting almost right away. Turned out final line stow was too tight, causing bag to begin rotating. Loosened it (used larger rubber band) and problem went away.

hope it's this easy for you too.

madjohn

Main goals in life: Be on the "Jumpers Over Eighty" (JOE) World Record and attend the Lost Prairie Boogie once after I'm gone.

Share this post


Link to post
Share on other sites

A fun little mystery. Well, maybe not quite as much fun for you :)
Canopy still in trim as JWest said? That's an easy suspect although you say it isn't supposed to have a huge number of jumps on the lineset. (What lines? Not the thin Spectra that goes out of trim the fastest?)

Packing technique ok? Not overstuffing the nose and creating some asymmetrical openings? As was mentioned, having someone else pack or also jump it is something to try.

Confirm again the PC is ok as lomcovak asked? The rigger confirmed for example that the kill line hasn't shrunk? (Something you should learn to spot too.) A slow bag liftoff allows it to bounce around or get spun by the elastics as they all pop off more slowly.

What kind of line twists are they? That's important to know in diagnosing the issue. Is it the type where you spin up on the canopy, or it spins up on you?

That is, is the canopy already twisted coming out of the bag, or immediately spin up on its own while deploying? (Which can be hard to see in time.) Or does the canopy deke left and right and suddenly dive off in one direction, throwing you around so that you end up getting the lines crossed and thus keep on rotating, creating all the line twists? Sounds a bit like the latter for you?

As for bag stowage direction, line stows towards the BOC is normal for basically every rig. Standing the bag 'upright', stows to the backpad, is an alternative that is generally accepted, works ok if the bag shape makes it fit ok, can be preferred in wingsuiting (much less bag rotation with a lot of forward speed) and could result in fewer issues. But you still have an underlying problem, whether or not standing up the bag might help.

Share this post


Link to post
Share on other sites
pchapman

Or does the canopy deke left and right and suddenly dive off in one direction, throwing you around so that you end up getting the lines crossed and thus keep on rotating, creating all the line twists?



what causes this?, I have had it happen a handful of times on my triathlon 190, and while I am usually able to stop it before line twists start, it does cause horribly off heading openings

Share this post


Link to post
Share on other sites
Sounds to me like your lines might be out of trim. Depending on what type of lines after 400 jumps they might need replacing. Even if they look good they might have shrunk depending on the type.

But I'd definitely have your pack jobs checked out or have someone else pack and see what happens and then go from there.

Share this post


Link to post
Share on other sites
Video of deployments will tell you for sure about symmetry (looking out at horizon, not looking or reaching up at the canopy).

The manual for your container will tell you how the deployment bag is supposed to be oriented (bridle towards top of pack tray or bridle towards closing flaps), and how long line bights should be for your container.

After that, bring some beer or dinner to your rigger at a not-busy time and talk to them. Maybe you just need to relax. Maybe you don't leave 18-21" of line unstowed and are all crazy about tucking the D bag in so tight it has to start a turn when leaving the container. An experienced rigger is your best resource - after you do the baseline work on your own.

Share this post


Link to post
Share on other sites
First is your container and dbag sized for a 190? What lines and what stows are you using? I have been packing grommet to pin for 10 years without issues.

If you suspect its the canopy send it to PD. They will check it out and test jump it for you.
Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

Share this post


Link to post
Share on other sites

I'll see if I can get a video of my deployment.

I think my lines are trimmed. They are supposed to just me slacked a little when completely released right?

I'm confused on how much line to leave unstowed. Vector 2 owners manual says no more than 15". Heard and read 18-24" before.

Not sure on my bag size. It fits in snug. I remember them saying when I bought it I could fit a different canopy size in it. Can't remember if it was a 210 or 170. If I remember correctly it was 170 in case I downsized. And I can't see fitting a bigger canopy in the bag.


Wondering if my dbag isn't the right one? Vector 2 owners manual says there are 4 grommets that hold it closed. My bag has 2 locking stow grommets then just band attachment points.

pchapman

A fun little mystery. Well, maybe not quite as much fun for you :)
Canopy still in trim as JWest said? That's an easy suspect although you say it isn't supposed to have a huge number of jumps on the lineset. (What lines? Not the thin Spectra that goes out of trim the fastest?)

Packing technique ok? Not overstuffing the nose and creating some asymmetrical openings? As was mentioned, having someone else pack or also jump it is something to try.

Confirm again the PC is ok as lomcovak asked? The rigger confirmed for example that the kill line hasn't shrunk? (Something you should learn to spot too.) A slow bag liftoff allows it to bounce around or get spun by the elastics as they all pop off more slowly.

What kind of line twists are they? That's important to know in diagnosing the issue. Is it the type where you spin up on the canopy, or it spins up on you?

That is, is the canopy already twisted coming out of the bag, or immediately spin up on its own while deploying? (Which can be hard to see in time.) Or does the canopy deke left and right and suddenly dive off in one direction, throwing you around so that you end up getting the lines crossed and thus keep on rotating, creating all the line twists? Sounds a bit like the latter for you?

A



A lot of good information trying to keep up with it all.


I'll have to ask about the lines. They feel kind of slick and they are on the thinner side. I've seen some people lines that look 2-3 times bigger and monstrous. Mine aren't those.

I'll ask about the PC again but I checked the kill line and it wasn't too short.


The more I rethink the opening the more i'm pretty certain the line twists are happening during and post deployment. It seems to open and then toss me around like a rag doll or spin me. As in past the point in deployment you can control stable body position, once i'm vertical under it.


Step one will be buying a couple good pack jobs but if I recall I was getting line twists from the first jump on it before I started packing. In fact i'm sure because I also saw my AFF instructor (who I bought it from) get line twists on it in the videos too!

Share this post


Link to post
Share on other sites
wildernessmedic

So try putting the D bag in this way instead of the way i've been doing it?



Pretty much. That should pull it straight off your back. Make sure all your rubber bands are the same size and all single stowed or double stowed. Don't mix the two this does not including your locking stows those should only be single stows.

We aren't talking just about your break lines being the proper length. We are talking about the other lines being out of spec. This generally happens from the grommets on the slider heating up the outside lines causing them to shrink. With 400 jumps on the line it couldn't hurt to have a rigger give it a look.

Share this post


Link to post
Share on other sites
Sorry about my earlier post as I don't know what happened to the second half and it won't let me edit it. Here is basically what it said:

In my experience, most times with 50 jumps experience, consistently experiencing line twist, packing is not entirely to blame. Body position during the pitch and throughout the opening can frequently mean the difference between an off-heading opening and a bunch of twists. Off heading you can tweak to improve, twists are something you need to correct.

In person, a rigger can easily help you to check over the gear to make sure it's not a contributor. We can internet advice your butt all day long but in-person is where it's at. Most of the advice I give when teaching deals with preventing hard openings and making tweaks to reduce wear on the gear.

For the packing end of things and the manual, knowledge on the subject has evolved in the years since the V2 manual was written.

Although I'd aim for 18" of line, a more important part would be proper force on the elastics - about 10 lbs for each stow. There have been many theories over the years but with good instruments and high speed videos the manufacturers learned that lots of the theories and beer tent advice were not supported by science.

The orientation of the bag probably makes little difference. I think there was a PD youtube video published that gives lots of technical advice on packing. At worse, give them a call and see what they suggest.

-Michael

Share this post


Link to post
Share on other sites
^ and then listen to your rigger. Ask questions if parts of the recommended packing process make you uncomfortable. Just because small bights or loose stows or every possible inch of line in bights or a particular bridle routing sometimes make people "feel better" doesent mean it will function properly.

Share this post


Link to post
Share on other sites
wildernessmedic


...I think my lines are trimmed. They are supposed to just me slacked a little when completely released right?...



Steering lines, yes.

But that's not what "in trim" means here.

It's talking about all the lines. The entire lineset.

It's not hard to check. You have to measure each line and compare it to what they are supposed to be.

You can find this on the PD Website.

A lot of people will have a rigger do this, but it's not anything difficult or special. You need to be able to use a tape measure.
"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy

"~ya don't GET old by being weak & stupid!" - Airtwardo

Share this post


Link to post
Share on other sites
My take on line checks is that normally one doesn't have to get into detailed measurements. Besides, in this sport (unlike paragliding) there are in general no firm go / no go requirements.

For a quick check just lay the canopy over your shoulder for propacking, and see whether the outer lines are shortened a lot compared to the inner. For thin white Spectra lines, one inch difference will happen pretty quickly, two inches might be typical of a well used but not too old line set, and three inches is a lot. But that's off the top of my head and one could argue about the numbers.

Any numbers are also only a guide -- a lot of line shrinkage may be an issue if the canopy isn't flying right, but not be considered an issue if the canopy is still opening / flying / flaring / front-risering / etc well.

Share this post


Link to post
Share on other sites
Hi,

as you will see by the Responses, the best way forward is to go tour your rigger and explain what is going on. he should make time to inspect all of the gear, including Line trim check and also check you Pilot chute and Kill Line.
if he cant find an issue with the gear, it is down to packing or body position. what way do you stow your lines in the container? do you fold your excess lines under the reserve tray or do they go straight down to the bottom of the container?
get someone to film your opening and that should make it clear if it is a problem with Body Position.

Rodger

Share this post


Link to post
Share on other sites
irishrigger

Hi,

as you will see by the Responses, the best way forward is to go tour your rigger and explain what is going on. he should make time to inspect all of the gear, including Line trim check and also check you Pilot chute and Kill Line.
if he cant find an issue with the gear, it is down to packing or body position. what way do you stow your lines in the container? do you fold your excess lines under the reserve tray or do they go straight down to the bottom of the container?
get someone to film your opening and that should make it clear if it is a problem with Body Position.

Rodger



So this is still an issue. It seems to be spinning once the D bag comes out.


PC is old, but rigger says its still fine, same with kill line.

I was told two things. Make sure there is less line from risers to first stow so it doesn't have a bunch to spin the D bag, and make sure my line stows are smaller.

How am I supposed to do both? If I make the line stows shorter I end up with more leftovers at the end.

I can't find any rhyme or reason. It is not body position. I've messed with my stows, and my nose. Sometimes it happens multiple jumps in a row, sometimes not. But there seems to be no correlation to how I packed.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

0