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camgon

Tight Closing Loop = Bag Lock??

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This past weekend was an unusal weekend for me in regards to my openings. I had TWO bag locks--the first cleared itself in about a second, the 2nd one I had to cutaway.

The Friday night prior, I tightened my closing loop. Very tight, albeit per manufacturer specifications (lined up grommets). That is the only "modifcation" I made to my gear prior to the weekend; there was no change in my packing style.

While it seems highly unlikely, my only guess is that somehow the extra tight closing loop is either causing some sort of deceleration of the pilotchute, or causing the kill line in the pilotchute to partially collapse, reducing in decreased drag. Here's the real kicker: on the one I had to chop, the bag was completely open. I could see that the tail and warning label on my canopy (i.e. the first S-fold) had come out of the bag, but the canopy was not coming out the rest of the way. This is what leads me to believe it's an issue with the PC, and NOT my stows (and yes, the PC was cocked).

The PC is relatively new. I bought it in the fall, probably about 150 jumps, so I don't think it's worn. Also I doubt the kill line is too short..in fact, it's a little long as usually the PC won't completely collapse and I have to get a lot of twists out of the bridle when I pack.

My canopy is a Nitro 150, which I've put about 50 jumps on without prior incident. Prior to that, I had a SabreII 170. Same D-bag as before, but Nitros tend to pack a size bigger, so it fits about the same.

Unfortunately, as I was cutting away the 2nd bag lock, it started to clear itself, so when I recovered the main, it was already out of the bag (i.e. I couldn't inspect the bag to see why it locked up). Any thoughts from the collective minds out there?

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Do you mean "container lock"/PC in tow? Otherwise, I cannot correlate how having a tight closing loop would affect/create/cause a bag-lock at all. ...???

Your malfunction type description here (either that, or the piece of gear you are referring to causing it) is confusing.

EDIT TO ADD: Just re-read. Apparently, you are either suspecting or trying to correlate IF the closing loop were too tight, it "stuttering" the launching PC at "bridal-stretch", and therein collapsing the PC which it wouldn't, and/or slowing the otherwise normal/expected "snatch force" for the bag to be stripped from the canopy?
coitus non circum - Moab Stone

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I think you need to define your terms.

Just because the grommets line up doesn't necessarily mean the closing loop is particularly tight or loose. In most cases, that's simply a function of pack volume vs container size.

What you really need to be concerned about is the amount of force required to pull the pin back out.

A quick, cheap and easy way to check this is to repack the rig just the way you've been doing. Put the rig on the ground and see what happens when you attempt to lift the entire thing up by the pilot chute bridle. Not exactly scientific, but if the pin doesn't come loose and you can pick up the rig via the bridle without the closing pin coming out, then you almost certainly have it too tight.
quade -
The World's Most Boring Skydiver

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What container did you have this issue with?

Your profile says you have a Vector 3. I don't think the grommets are supposed to line up on the Vector 3 containers. I am pretty certain they are supposed to be offset.



Agreed

Here's a part of a photo in the V3 manual

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But I think he stated the bag was out, so the PC did pull the pin.

But is it possible that the force was too high, and that perhaps what really might have happened is that he had a temporary pilot chute in tow, which eventually cleared itself, and that he just so happened to look back right at the time the lines extended (and erroneously thought they had been extended for some time)? (Just trying to come up with some scenario where the closing loop length would at least appear to affect extraction from the bag.)

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But I think he stated the bag was out, so the PC did pull the pin.

But is it possible that the force was too high, and that perhaps what really might have happened is that he had a temporary pilot chute in tow, which eventually cleared itself, and that he just so happened to look back right at the time the lines extended (and erroneously thought they had been extended for some time)? (Just trying to come up with some scenario where the closing loop length would at least appear to affect extraction from the bag.)



Right, but let's start by looking to see what sort of forces he's actually talking about when he's saying it's possibly "too tight."

The next thing up on the scale of scientific inquiry would be attaching a spring scale to the bridle and seeing how much force is actually required to extract the pin. I'm assuming he doesn't have one handy, but his rig probably weighs in the neighborhood of 20 pounds.
quade -
The World's Most Boring Skydiver

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Just so everyone is clear, this was not a PC in tow. I'm also very skeptical that the tight(er) closing loop is responsible, HOWEVER, considering that it happened twice in one weekend, AND the closing loop is the only thing I changed, it leads me to the conclusion, no matter how improbable it seems.

There of course is likely some other issue that occurred that I'm not aware of, and that the closing loop is coincidental, which is why I'm looking for answers here.

In regards to looking up too soon, as someone suggested, that is not the case. I can assure you that when my body is angled not quite vertically from the snatch, and I look up to see nothing but my D-bag at line-stretch for 2 seconds, it's some sort of bag lock. :P

What's strange is both times it happened, I started to fall into the saddle just a split second early--it almost felt like the trap door effect when you pull the drogue release on a tandem. We all know what if feels like when the timing of a deployment is off, even if it's microseconds...that feeling occured both times.

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There of course is likely some other issue that occurred that I'm not aware of, and that the closing loop is coincidental, which is why I'm looking for answers here.



I do not see how closing loop tightness, can have any affect or bearing, let alone have direct correlation in of itself to creating a bag lock. But maybe someone else can?

You are thinking that either the PC being temporarily halted, or slowed (what I called "stuttering" before) as a result of a "too tight" closing loop, could be a possible cause? - Or that it caused the collapsible PC to collapse at pin-snatch, rather than bag opening/canopy extraction? I don't think that would occur/result either - so looking at the closing loop change as being causal to this, I think - is a red herring.

Is your collapsible PC kill-line or bungee?
coitus non circum - Moab Stone

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I would be sure that you are getting a full extension of the kill line and the PC can fully inflate. After you have cocked the PC hold it by the base and make sure the tape(s) has no slack. Or simply is the PC old, especially a F111 PC.
Be Safe and Have Fun, in that order!
Tuffy

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I would be sure that you are getting a full extension of the kill line and the PC can fully inflate. After you have cocked the PC hold it by the base and make sure the tape(s) has no slack. Or simply is the PC old, especially a F111 PC.



I agree and if you are jumping a Vector do NOT line up the grommets!
Life is all about ass....either you're kicking it, kissing it, working it off, or trying to get a piece of it.
Muff Brother #4382 Dudeist Skydiver #000
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This past weekend was an unusal weekend for me in regards to my openings. I had TWO bag locks--the first cleared itself in about a second, the 2nd one I had to cutaway.....



I would suspect the line stows - type of stow and length of the line bite past the stow band.
I see a lot of pack jobs that would allow the closing stows to fall over another stow or visa versa.
The bite length needs to be uniform and not long enough to hang up on an adjacent stow.

If you have changed stow bands are you using ones that will break at the same force as before?

.
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Make It Happen
Parachute History
DiveMaker

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I would be sure that you are getting a full extension of the kill line and the PC can fully inflate. After you have cocked the PC hold it by the base and make sure the tape(s) has no slack. Or simply is the PC old, especially a F111 PC.



The PC is new, just got it last fall. I after cocking the PC, not only do I check the window, I also always do a manual check to see if and how well it's catching air. I don't usually visually check to see if the tape is fully extended though, but I'll try that (when I get my rig back from my rigger).

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This past weekend was an unusal weekend for me in regards to my openings. I had TWO bag locks--the first cleared itself in about a second, the 2nd one I had to cutaway.....



I would suspect the line stows - type of stow and length of the line bite past the stow band.
I see a lot of pack jobs that would allow the closing stows to fall over another stow or visa versa.
The bite length needs to be uniform and not long enough to hang up on an adjacent stow.

If you have changed stow bands are you using ones that will break at the same force as before?

.


At first, I suspected line stows were the issue, as did the people I asked at my DZ, especially since line stows are usually the culprit when it comes to bag locks. However, the 2nd "bag lock", which I had to cutaway, really wasn't a bag lock at all in the typical sense. The bag was open all the way, and I could see the tail of my canopy (the first S-fold) had come out, but the rest of the canopy wouldn't come out of the bag.

Just for reference, I use the larger rubber bands for all my stows. I single stow the first 2 locking stows, and double stow the outer locking stows and the excess line stows. All my stows have a 1.5 to 2" bight. I know there are differing opinions between small/large rubber bands, and singe/double stowing, but I'm not really looking to get into that in this thread. ;)

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What container did you have this issue with?

Your profile says you have a Vector 3. I don't think the grommets are supposed to line up on the Vector 3 containers. I am pretty certain they are supposed to be offset.



It's actually a V-3 Micron, though I don't know if that will make a difference.

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What container did you have this issue with?

Your profile says you have a Vector 3. I don't think the grommets are supposed to line up on the Vector 3 containers. I am pretty certain they are supposed to be offset.



It's actually a V-3 Micron, though I don't know if that will make a difference.


Nope, shouldn't make a difference in this case. I've had 3 Microns - 2 V310's and a V304. According to the manufacturer, all have been designed to have the grommets not aligned.

(Not sure that that could be the cause, but I suppose stranger things have happened. Regardless, weird story! Congrats on the successful chops!) B|
Signatures are the new black.

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However, the 2nd "bag lock", which I had to cutaway, really wasn't a bag lock at all in the typical sense. The bag was open all the way, and I could see the tail of my canopy (the first S-fold) had come out, but the rest of the canopy wouldn't come out of the bag.



Then I would then suspect that the canopy is too large for the bag and has a hard time getting extracted from it
or your bag stop is improperly placed that would inhibit the canopy from being extracted.

.
.
Make It Happen
Parachute History
DiveMaker

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It's actually a V-3 Micron, though I don't know if that will make a difference.



All of UPT rigs are designed such that the grommets are NOT supposed to be 'lined up' or 'on top of each other'.
There are a number of reasons for this.
So I would say that your closing loop was adjusted to be too short and you need to lengthen it.

.
.
Make It Happen
Parachute History
DiveMaker

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Well, it sounds like I'll be lengthening my closing loop. I didn't realize the grommets weren't supposed to line up for Vectors. Now, my original intention wasn't to line them up, and they're still not perfectly in line, but my closing loop was just a bit long and in the process of shortening it I figured I might as well go all the way.

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However, the 2nd "bag lock", which I had to cutaway, really wasn't a bag lock at all in the typical sense. The bag was open all the way, and I could see the tail of my canopy (the first S-fold) had come out, but the rest of the canopy wouldn't come out of the bag.



Then I would then suspect that the canopy is too large for the bag and has a hard time getting extracted from it
or your bag stop is improperly placed that would inhibit the canopy from being extracted.

.



You would think based off what happened that the canopy is too big, but I've had both of my previous canopies in the same D-bag (SabreII 190 and 170, respectively) without any problems. Now, the Nitro 150 DOES pack a size big, but that would still put it in the 170 range.

I'm not quite sure what the bag stop is.

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Well, it sounds like I'll be lengthening my closing loop. I didn't realize the grommets weren't supposed to line up for Vectors. Now, my original intention wasn't to line them up, and they're still not perfectly in line, but my closing loop was just a bit long and in the process of shortening it I figured I might as well go all the way.



Should really read the manual. Not only does it look better with the grommets staggered properly, the main pin flap usually actually fits better.
"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
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I am sure you do it right but just in case...
Do you full cock you PC before insert the pin (put bag into conteiner and closing flaps)?
Do you cock PC by pulling the PC's handle or directly pulling out the killline (which actaully give you "more cocked" PC since more kill line pulled)?
Why drink and drive, if you can smoke and fly?

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I am sure you do it right but just in case...
Do you full cock you PC before insert the pin (put bag into conteiner and closing flaps)?
Do you cock PC by pulling the PC's handle or directly pulling out the killline (which actaully give you "more cocked" PC since more kill line pulled)?



No, because the PC will only open up as big as the support tapes will allow it.
"I may be a dirty pirate hooker...but I'm not about to go stand on the corner." iluvtofly
DPH -7, TDS 578, Muff 5153, SCR 14890
I'm an asshole, and I approve this message

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Do you cock PC by pulling the PC's handle or directly pulling out the killline (which actaully give you "more cocked" PC since more kill line pulled)?



No, because the PC will only open up as big as the support tapes will allow it.


By handle, PC can only be initially cocked (kill line pulled out) as much as support tapes allow it...
During futher packing kill line can (and usually does) pulled in back
So I prefer Full cocked PC (when it present a slack on the kill line while support tapes are stretched with handle at final cheking)
Why drink and drive, if you can smoke and fly?

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