Stowing a 48-inch pilotchute

[TomAiello 25]

Tree, Johnny,

Enough already. Let's keep this discussion about the technical topic at hand (large PC's, stowing them, and techniques for stowing them).

3rd grade playground insults are silly and counterproductive. Dredging up old posts that people made about topics unrelated to this discussion isn't terribly useful either.

I'm banning both of you for 24 hours. That ought to give you time to cool down and cut it out, but still let you return to the productive, technical parts of this discussion to offer input.

Consider this your warning.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[wwarped 0]

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insults are silly and counterproductive. Dredging up old posts that people made about topics unrelated to this discussion isn't terribly useful either.

hmmmm...

I've been around long enough to know I could learn a lot from JohnnyU, Tree, Tom, and others.

I also know BASE is getting many new participants. they will know little about past offenses and won't search the archives. what they know will be based primarily on what gets posted NOW.

please watch what you say. your presentation can seriously distract from very important points.

as an example, I've heard nothing but praise regarding Johnny's FJC. he can teach newbies vital skills. but I fear the less than professional posts might discourage people from taking his course. that would be a big mistake.

to all:
let the past be. be friendly, helpful, and lead the new jumpers. don't discourage them from reading your posts.

DON'T PANIC
The lies in learning how to throw yourself at the ground and miss.
sloppy habits -> sloppy jumps -> injury or worse

[yuri_base 1]

What physically causes 48" to hesitate more often than 42?

Is there a known connection with how long before the jump PC was packed? I always repack PC as close to jump as possible. On my accident jump, I repacked PC on top of the cliff just minutes before the jump. It was stored in the pouch for about a week and was quite dense and retaining its dense cylinder shape with almost no expansion. It took me a couple of strong yanks to completely unfold it.

Bigger PC is compressed in the pouch stronger and may take longer to unfold in the air stream.

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[TomAiello 25]

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What physically causes 48" to hesitate more often than 42?

I think it's mostly just a "more fabric takes longer to unfold, and has more chance for random factors" kind of thing.

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Is there a known connection with how long before the jump PC was packed?

Definitely. On stowed jumps where I really want to avoid hesitation, I tend to repack my PC at the exit, after airing it out a bit. If I know I'm doing something stowed and don't want a hesitation, I'll sometimes leave the PC unpacked and out of the stashbag, as open as possible, when I pack the rig, and then just pack the PC when I gear up.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[RayLosli 11]

OK, keeping this discussion about the technical topic at hand. I have just a few thing to say.about believing every thing you hear and read about concerning BASE Safety Facts. - ESPECIALLY POLES
-
-
jaap:
..."Going at it alone is great, but there's a ton of little facts -like this one about large pilotchutes- that you won't pick up unless you start hanging out with experienced jumpers."
"Anyway, just curious what the poll will say. Maybe I'm wrong and everybody learned this during their FJC".
Cheers, Jaap

-
Wow. Just curious. Have you -Jaap- or any of you Bozo's (scardy cats) ever done even a Hundred Stowed jumps with a 48- inch Pilot-Chute BASE jumping ?
No - Is that what you all are saying ?
Then how the hell do you ALL Know It Will Hesitate ? Because that is what you have heard or been told ?
How can you - ALL just AGREE - with this Hesitation Theory. Without Trial of experimentation ?
You Do Not Know This Is A Fact. For me this is not a Sound Theory.
A 48-inch PC Stowed. Does NOT promote Hesitation.
.
I have done and Logged, Several Hundred Jumps over Several Years of using a 48" STOWED and have Never experienced any Hesitation in Tow.
That is ALL I ever used to jump Stowed for YEARS. was a 48-inch.
I believe this Hesitation Theory on going Stowed 48-Inch is called a, Hypothesis (educated Guess) Not Fact.
.
So I am going to have to call Bullshit on the - Hesitation Theory - when going stowed with a 48-inch Pilot Chute.
Just on the plain FACT that I have done a HUGE amount of Stowed Jumps. With a 48" PC. Several Hundred actual BASE jumps. over a Several Year period.
I believe you call this 1st hand Knowledge. (Reality), Done by ACTUALLY Doing It. Not Hypothesis (guessing).
.
.

[yuri_base 1]

It's like a scientist is plotting a few scattered data points, and drawing a theoretical curve to best fit these points. Suddenly, a new batch of data (hundreds of points at the opposite side of spectrum) arrives and overturns the previous theory.

It would be interesting to hear details of the 48" hesitations. How long before the jump the PC was packed? Was it made of that sticky ZP that almost killed Jaap? How new/old was it? What was the folding method?

As an unexperienced jumper, my small contribution is that 42 has a greater variability in opening height on 0-2s delays than 48, which seemed to be very consistent from jump to jump, stowed or handheld.

Android+Wear/iOS/Windows apps:
L/D Vario, Smart Altimeter, Rockdrop Pro, Wingsuit FAP
iOS only: L/D Magic
Windows only: WS Studio

[nicknitro71 0]

Here is my 0.02.

First Yuri's strike was due to body position not the PC.

I do not stow anything bigger than a 42 for the reasons mentioned by you and others.

However I've had hesitations using a 46 vented (HH), few times. Ever since I switched to a 46 (same brand and fabric) with no vent, disk, or handle no more hesitations...

New jumpers are attacted by the "cool" factor about going stowed. Forget about exiting stable and on heading, as long as they go stowed it's all good.

I heard few times from a wise man that going stowed below 300' is asking for trouble...

As for the 48" I don't use one.

And for stir in some more crap to the mix. DW used to do gainers off a 180 stowed with a 52", go figure!

Memento Audere Semper

903

[JaapSuter 0]

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Wow. Just curious. Have you -Jaap- or any of you Bozo's (scardy cats) ever done even a Hundred Stowed jumps with a 48- inch Pilot-Chute BASE jumping ?

Are you calling me a scardy cat and bozo, or did you exclude me from that monniker by explicitly mentioning my name?

Just checking...

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Then how the hell do you ALL Know It Will Hesitate ? Because that is what you have heard or been told? How can you - ALL just AGREE - with this Hesitation Theory. Without Trial of experimentation ?
You Do Not Know This Is A Fact. For me this is not a Sound Theory.

I haven't done a hundred jumps without a tailgate, yet I jump with one. That's silly too then? I haven't done a hundred BASE jumps with a skydiving setup, should I do so just to make sure I statistically prove to myself it's a bad idea?

When sufficient experienced jumpers tell me it might be a bad idea, and I combine that with what my own common-sense is telling me, and put on top of that the fact that stowing a 48 inch PC doesn't buy me anything (when I stow, the altitude allows a smaller PC anyway), the only natural conclusion is to avoid it.

There's no rocket science to it...

[TomAiello 25]

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Note that I am of the opinion that folding a mushroom (of any type) with a big PC and hand holding it for a short delay creates virtually identical hesitation issues as stowing the mushroom.

Do you have any theories on why this might happen?

Some theories:

Although I've got some video evidence to support these, I wouldn't say that I've seen anything conclusive, so they're still just theories:


1) More folds in = More folds out.

The more folds that you put into a PC when you prepare it, the more folds that have to come out of it before it can inflate. When the mushroomed PC hits line stretch, it still has to "de-mushroom" before it can reach a fully extended state. A PC that is simply S folded unfolds itself as it reaches bridle stretch. Because there are no folds "around" itself, it is fully extended immediately upon reaching bridle stretch, eliminating the unfolding process, and hence eliminated a few of the chances for hesitation (say, if one side of the ZP folds manages to somehow slip "under" the bundle, and it takes a few fractions of a second for them to straighten out and get into a "ready to inflate" position).


2) Deformation of the mushroom.

As you pitch a mushroom to bridle stretch, the center of the mushroom, where the bridle is, has a greater mass than the outside of the mushroom, where the ZP is. As the ZP begins to expand outward, it experiences more air friction than the (covered) inner part of the mushroom (typically the mesh, but more importantly the bridle folds). As the outside fo the mushroom (the ZP) begins to slow and expand a little outward, the (still travelling faster, and experiencing less slowing) bridle bundle pushes tighter into the apex of the PC, essentially creating a condition in which the PC is trying to invert itself. This is not an ideal pre-state for PC inflation, and the "undoing" of this condition introduces more variables, as well as more required time, prior to the PC reaching a "ready to inflate" position.


They're just theories, as I said.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[TomAiello 25]

Ray,

Does your 48 have a vent, cap or handle on the apex?

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[RayLosli 11]

Just joking as usual - (scardy cats)
You are the Author (starting) of another BASE jumping Pole is the only reason that I used your name at all. Not Picking on you in particular. (hear that rl ?)
.
We are not talking about Line-Over as stated by you as an example. The benefits of Tail-Gate use has be documented by Years and countless Thousands of BASE jumps as Proof to the Reality of it's Efficiency and benefits of reducing the Line-Over. Tis is called. Trial by Experiment.
.
The Statements, Going Stowed with a 48" PC causes Hesitation. People (BASE Jumpers) are telling you it's bad. But I do Not hear anyone or Read any Data on Numbers of jumps by FACT. Only hearsay and a some Isolated and negative experiences with a 48" and going Stowed. Spread Over and Over and Over by story told and handed down from mouth to mouth and spread like a symptom of a Common Cold, By Internet Chat. With no proof or hard Numbers to back it up. Leeding to this Wives Tail of BASE safety No-No's not to do.
I have put in some Hard Numbers. That is plain Just Fact.
.
I am NOT Bragging. This is just the way things Accidentally worked out. Fact is I have Done hundreds of BASE jumps going Stowed with a 48" PC with no hesitations. The only reason I even slowed the use of a 48" for the majority of jumps in the year of 2005. Was that It gives me a Favorable advantage on the positive side. When there is less distortion on the Flair when I land using a 42-Inch. Only because my legs and Back are getting sore lately. When thing work good for so long and are not broken. I don't try to Fix it. (My basic survival Rule).
I am only stating the fact that this mechanical combination combined with my personal mechanical habits and techniques in relation to Me. Tossing Out My 48" pilot chute Stowed have worked successfully for sum time now. With no adverse affects for Years.
Dispite What the Law of the Land CLAIMS as, Hesitational-PC Fact.
-
jaap:
..."and I combine that with what my own common-sense is telling me, and put on top of that the fact that stowing a 48 inch PC doesn't buy me anything (when I stow, the altitude allows a smaller PC anyway), the only natural conclusion is to avoid it'.
.
These kind of statements are what I am talking about. (and it's not just you)
We are Not Talking about the 48" Stowed and extracted on Freefall. Buying you any Benefits. We are talking about Hesitation caused by 48" going Stowed. Added by this Safety BASE Rule that was added with out any Hard Numbers to back it up. Passed down to You. Then you stating this along with the internet Pole - BASE Chat. Ending with the conclusion to, Avoid It. Which ADDS to this, BASE Wives-Tale of. - Going Stowed with a 48" PC causes Hesitation.
.
As you state. "There's no rocket science to it...
.

[RayLosli 11]

tom:

"Does your 48 have a vent, cap or handle on the apex"?
.
Only a 1000 Den. Cordura Crown Cap. Just an average looking 48" PC I sew up in Garage.
I think I still use the original 3-48" PC's I made up. I don't know when ? they work and I don't change them.
PC construction methods is not what I am getting at here though.
.

[JaapSuter 0]

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We are talking about Hesitation caused by 48" going Stowed.

No, we are talking about whether or not this has a higher probability of hesitating compared to stowing smaller pilotchutes.

Although strictly speaking I actually started the thread to point out there are things you won't learn in your FJC, and that's why we should hang out with experienced jumpers.

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Which ADDS to this, BASE Wives-Tale of. - Going Stowed with a 48" PC causes Hesitation.

You never heard me say that. I did say it has a higher chance of hesitating compared to stowing smaller pilotchutes.

I won't debate whether or not this is true. I must admit your point of view is refreshing, and it's an interesting reminder that we shouldn't always take for granted what other experienced people tell us.

That said, I still don't see a reason to go stowed with a 48 inch PC since I enjoy going handheld at those kind of delays. Perhaps when accessing a sketchy exit point, but I'm a scaredy cat so I'll probably avoid an object like that anyway.

Thanks Ray...

[RayLosli 11]

Hey no Problemo..... Like I stated it's not just what you are saying in particular. The thread led to some Safety conversations that 48" PC's have hesitation habits.
Hey I will go Stowed if the occasion calls for it. Also for all those many stowed 48" PC jumps. A 42" might have worked just fine also. I just find it difficult to accept some Rules, and most BASE jumpers do. Especially one that has no proof to back it up.
And Dude I am a (Scardy Cat) at times and a cautious BASE jumper. Or I would not have lived for this long....
.
edit change: for mi spelin suks
.

[Faber 0]

I never said it would hesitate,but my guess is that its more prone to do so.
My real concern about LARGE pc´s in your BOC is:
1st. larger BOC means bigger chans of loosing the beer you just stashed there before you jump off a legal S
2.nd Larger ´pc means less space in the BOC,which will require a stronger pull,a stronger pull can cause stability problems causing offheaddings,which can ruinyour day
3.th i THINK that forcing that much material together will keep it tight and on a bad day it MIGHT cause a hesi.

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I have done and Logged, Several Hundred Jumps over Several Years of using a 48" STOWED

Only becourse you thourght that a 42´couldnt carry your fat arse

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and have Never experienced any Hesitation in Tow.

how can you tell,from what i heard you close your eyes soon as you leave the exitpoint and opens them first under canopy,perhaps you thourght you packed slider up and didnt think of the difference

hope your all good bro

Stay safe
Stefan Faber

[RayLosli 11]

faber:
..."and have Never experienced any Hesitation in Tow.
how can you tell,from what i heard you close your eyes soon as you leave the exitpoint and opens them first under canopy,perhaps you thourght you packed slider up and didnt think of the difference"
----

Hey I have had only, 1- PC in Hesitation on a BASE jump.
It was exiting from 210-feet going Hand Held. Which led to a 1-1/2 second Canopy Ride.
.
Hey and the only reason I close my eyes on a BASE jump Is because I am Tired.
Tired from staying up all night. Drinking and Playing with your Momma !......
.

[Treejumps 0]

Hi Ray,

Nice post with good data to back it up. I have done many jumps with a 46" stowed. A lot less than you, but enough to not think that it can't be done. On my first B I went stowed with a 46", and opened a lot lower than the more experienced jumpers who wisely went HH. After dodging a construction trailer I gave a lot of thought to how big the difference in opening altitudes was between HH and stowed. In the context of telling new jumpers I think this a case of do as I say, not as I do. I would go stowed with a 46 or 48, I just wouldn't tell new people that it was a great idea, survivable, yes, repeatable, yes again, but probably not something that inexperienced jumpers "should" do. Once they have experience they can make choices based on their knowledge, skill, and risk appetite, but early on (which was the context of the original poll) I would not reccomend it.

Please don't "hesitate" to post more.

Cya!

[460 0]

Its from the dramatically increased fill volume for a super large PC versus an average size PC that causes the potential for more hesitation in addition to the longer unfolding process.

***
1) More folds in = More folds out.

The more folds that you put into a PC when you prepare it, the more folds that have to come out of it before it can inflate. When the mushroomed PC hits line stretch, it still has to "de-mushroom" before it can reach a fully extended state. A PC that is simply S folded unfolds itself as it reaches bridle stretch. Because there are no folds "around" itself, it is fully extended immediately upon reaching bridle stretch, eliminating the unfolding process, and hence eliminated a few of the chances for hesitation (say, if one side of the ZP folds manages to somehow slip "under" the bundle, and it takes a few fractions of a second for them to straighten out and get into a "ready to inflate" position).

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Looks like a death sandwich without the bread - Steve Deadman Morrell, BASE 174

[TomAiello 25]

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In the context of telling new jumpers I think this a case of do as I say, not as I do. I would go stowed with a 46 or 48, I just wouldn't tell new people that it was a great idea...

I completely agree.

When I was younger (some would say more foolish), I used to go stowed from low altitude a lot. I'd regularly be the only stowed guy on the load, with a 46" or 48" in my BOC. Even after a noticeable hesitation stowed from about 240', I kept doing it.

I like to think that I'm older and wiser now. My personal limit for stowed is probably riding right around 300' nowadays.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[Fledgling 0]

I think it's pretty good, but I like the "S fold everything" method better, for two reasons. (1) I think it gets a tighter bundle to throw to full bridle extension, and (2) as noted a longer delay can cause the ZP to start inflating and create some stability problems if you let it slip around in your grip

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What do you mean by 's' fold everything do you mean the the entire pc, bridle, mesh and zp? I'm new to this but if I understand you correctly then I have never seen any one use this method before.

[TomAiello 25]

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What do you mean by 's' fold everything do you mean the the entire pc, bridle, mesh and zp?

Yep. Jaap described it pretty well earlier in this thread. When I started jumping this was the standard method for handheld pilot chutes. I know that it was still pretty standard at an IPBC event I went to around 2001 or 2002. It's still the method I teach. I'm really not sure when or why so many people started trying to create "improvements" to this method. I can say with certainty that Dwain chose to use this PC folding method for his ultra low jumps because he felt it gave the least chance for PC hesitation outside the "Feteris" method (PC pretty much full inflated before you leave the exit).

Is there anyone out there who initially learned this method and later changed to some kind of hand held mushroom? Can you tell us why you made the change?

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[Fledgling 0]

[kleggo 138]

Sorry can't respond to the poll because this option does not exist.

Never did it because it was so obviously a bad idea because of pouch / pilot chute size incompatability and why the hell would you want to go stowed if you needed a 48" pc anyway option?


be safe

kleggo

[JaapSuter 0]

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If your worried about making sure that the top of your pc is left facing upwards then why don't you just start your sfolds there and work your way down?Is there any specific reason to start your sfolds at the bridle or is it just the way you were taught?

It's not really a worry, it's just that I sometimes have to backtrack one or two folds on the mesh to make sure I come out correctly.

You're making an interesting observation though and the only honest reason I'm not doing that is because I've never tried it. I will do so as soon as I come home. I'm not convinced it will be easier, but who knows...

Thanks!

P.s. just so as long as we always make sure the bridle comes out the top of the hand (between the thumb and the index finger).

[TomAiello 25]

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If your worried about making sure that the top of your pc is left facing upwards then why don't you just start your sfolds there and work your way down?Is there any specific reason to start your sfolds at the bridle or is it just the way you were taught?

It's not really a worry, it's just that I sometimes have to backtrack one or two folds on the mesh to make sure I come out correctly.

You're making an interesting observation though and the only honest reason I'm not doing that is because I've never tried it. I will do so as soon as I come home.

Many people fold the PC into their opposite hand, starting at the top, then switch it into their pitch hand once they finish folding. That way the top is in the palm of the hand as you fold it, to keep it controlled, until you switch it into the other hand.

The reason for starting the folds at the bridle is so that you can measure the bridle length over your shoulder, down your arm, and into your hand, before you start folding.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com