0
erdnarob

Scary reserve Dbag hand extraction

Recommended Posts

Quote

Someone already has addressed your follow on concerns above. It will differ from manufacturer to manufacturer slightly no doubt but the real impossibility to calculate or test for is those rigs that have had reserves shoehorned into the pack tray and have exceeded the specifications of the manufacturer. I don't think designers have created the problem at all, riggers who cram parachutes into a rig to the point that these excessive forces are required to extract the reserve are at fault IMHO.



We have a winner.....no more calls.

Sparky
My idea of a fair fight is clubbing baby seals

Share this post


Link to post
Share on other sites
Last time I checked, no one is holding a gun to any riggers head forcing them to pack any rig. So at the end of the day, there might be other factors involved as mentioned but ultimately its the rigger who stuffs 10lbs into a 5lb bag knowing its not ideal. So unless someone has a gun to your head, there should be no reason why any rigger should feel obligated to pack a system that they feel has component parts that are going to create these types of situations. It's a matter of doing the right thing, even if the customer asks/insists that you put that reserve you know is too big in. A simple "NO" with an explanation why you won't pack it should be all you have to say.

If the next line of thought is "well if I don't do it, another rigger will" then I say more riggers should stand up and do the right thing ( wishful thinking I know) but ultimately, at the end of the day do you want to know that you jammed something in a rig to make a few bucks that contributes to and or results in someones death when the system doesn't work properly just so you could make those few bucks and another rigger doesn't? Hence, I say this is a rigger issue when you remove all the rationalization/excuses from the picture.
"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

Share this post


Link to post
Share on other sites
Attached are published canopy sizes for container sizes. A rigger is obligated to work within these limitations. To pack a reserve canopy that is larger than the specs. given by the manufacture could be viewed as a violation of the TSO.

Sparky
My idea of a fair fight is clubbing baby seals

Share this post


Link to post
Share on other sites
Hi Scott & RiggerLee,

Quote

no one is holding a gun to any riggers head forcing them to pack any rig.



I have mentioned this before in another thread.

My best friend in skydiving ( and a friend for 40 yrs ) has bought two new rigs that I assembled & did the initial packing for. When I finished, I told him not to bring them back to me again.

On the second one I made two calls to the mfr to ask if this would actually fit. He assured me that the canopy/container combination was OK.

In a later discussion, he mentioned something about 'secret stuff' to getting them packed OK.

I have yet to read of any 'secret stuff' in any manual.

We just have to step up and say 'No.'

JerryBaumchen

PS) Many years ago, Mike Tuffer had an editorial in SKYDIVING magazine that suggested that anyone buying a new rig, should buy it one size larger than recommended for both the main & reserve that you own.

Share this post


Link to post
Share on other sites
Quote

Attached are published canopy sizes for container sizes. A rigger is obligated to work within these limitations. To pack a reserve canopy that is larger than the specs. given by the manufacture could be viewed as a violation of the TSO.

Sparky



I understand what you are saying, but making charts based on the surface area of the canopy instead of the packing volume is not right.
2 canopies from the same size can have different packing volume by a lot. ( I'm sure you know that better than me, but I'm just trying to explain to others why this is not a good idea )

The way to go is giving the packing volume for the rig size. Like Basic Air, Jump Shack, Rigging Innovations , and leaving it up to the rigger to decide which model and size reserve will go into that rig.

With all that said, it still won't be good enough :S
"My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen

Share this post


Link to post
Share on other sites
Quote


I have yet to read of any 'secret stuff' in any manual.



I was going to mention something like that as an add-on to RiggerLee's comments! While some manuals do provide useful tips and emphasis, I've even had a new rig come packed fresh from the factory, in a way contrary to the manual.

"Secret stuff" becomes like some little status contest among riggers ("I can pack that rig tighter than you can! Bet my loop was 1/4" shorter!"), rather than allowing an average but committed rigger to provide a safe pack job for the customer that doesn't unduly stress the rig.

Share this post


Link to post
Share on other sites
Quote

Quote

Attached are published canopy sizes for container sizes. A rigger is obligated to work within these limitations. To pack a reserve canopy that is larger than the specs. given by the manufacture could be viewed as a violation of the TSO.

Sparky



I understand what you are saying, but making charts based on the surface area of the canopy instead of the packing volume is not right.
2 canopies from the same size can have different packing volume by a lot. ( I'm sure you know that better than me, but I'm just trying to explain to others why this is not a good idea )

The way to go is giving the packing volume for the rig size. Like Basic Air, Jump Shack, Rigging Innovations , and leaving it up to the rigger to decide which model and size reserve will go into that rig.

With all that said, it still won't be good enough :S


You are right. I should have used something like these for an example.

Sparky
My idea of a fair fight is clubbing baby seals

Share this post


Link to post
Share on other sites
Aren't we a bit premature in concluding that a reserve too large for the container is at fault for this incident?

I agree that overstuffed reserve containers is a problem. It has been shown to contribute to PC launch hesitation and freebag extraction issues, but it doesn't seem that we know enough to assign fault yet for this incident.
People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

Share this post


Link to post
Share on other sites
Quote

Quote


I have yet to read of any 'secret stuff' in any manual.



I was going to mention something like that as an add-on to RiggerLee's comments! While some manuals do provide useful tips and emphasis, I've even had a new rig come packed fresh from the factory, in a way contrary to the manual.

"Secret stuff" becomes like some little status contest among riggers ("I can pack that rig tighter than you can! Bet my loop was 1/4" shorter!"), rather than allowing an average but committed rigger to provide a safe pack job for the customer that doesn't unduly stress the rig.



I think part of the issue is that many rig manufacturers are not able to invest a lot of money in keeping their documentation up to date. Every year I try to hit up a different manufacturer and ask their riggers to show me the tricks to packing their rigs.

Seldom are these tricks in the actual manual. The manual is written or updated from a previous design and the rig goes into production. After assembling and packing 500 rigs the staff riggers find/invent these little tricks but there is seldom the time and money to go back and revise the manual to publicize these little things.

Back on the original topic many of the rigs out there won't let the reserve out if you're stuck in a back to earth configuration. One would expect the 100lbs or so of drag from the reserve PC to roll the skydiver over but not always.

-Michael

Share this post


Link to post
Share on other sites
Quote



What you have to take into account is that small rigs, overstuffed reserves and low drag reserve PCs make this scenario more likely to happen regardless of the body position .



As I said when I discovered that highly loaded reserves were being used, who thought that LOW DRAG RESERVE PILOT CHUTES were a good idea?

Fcuk, you guys are dying for fashion!

It's the skydiving version of ANOREXIA but quicker FFS>:(

Share this post


Link to post
Share on other sites
Quote

John Sherman recently published an article about reserve freebag extraction angles. You can read it on Jump Shack's website.



As an adendem to that article I would say that the drag of the reserve pilot chute should be sufficient to re-orientate the jumpers body to a normal extraction attitude. In other words the pilot chute should "Jerk" you around. From any angle it is the drag of the pilot chute vs. the bag extraction force when measured at it's lowest level.

Jumpers should demand to know the "Effective Size" (Cd*So) of their pilot chutes. If the manufacturer can't tell you "Buy something else"

John

Share this post


Link to post
Share on other sites
Quote

Hi Michael,

Quote

the 100lbs or so of drag from the reserve PC



1. Where did you come up with this value?

2. And at what speed would you expect this value to appear?



The reason for the "or so" is that it is a ballpark value to give the reader a feel for the idea being communicated. If the intent was to provide a calculated value with some precision the wording would have reflected that.

http://www.youtube.com/watch?v=04-wne9QL2E&t=1m20s
As an example on a different rig, deployment occurs after the pilot chute passes over the shoulder to reach full extension but not before the jumper rolls over from the back to earth position.

-Michael

Share this post


Link to post
Share on other sites
Quote

Quote

Hi Michael,

Quote

the 100lbs or so of drag from the reserve PC



1. Where did you come up with this value?

2. And at what speed would you expect this value to appear?



The reason for the "or so" is that it is a ballpark value to give the reader a feel for the idea being communicated. If the intent was to provide a calculated value with some precision the wording would have reflected that.

http://www.youtube.com/watch?v=04-wne9QL2E&t=1m20s
As an example on a different rig, deployment occurs after the pilot chute passes over the shoulder to reach full extension but not before the jumper rolls over from the back to earth position.

-Michael




Clickified










~ If you choke a Smurf, what color does it turn? ~

Share this post


Link to post
Share on other sites
Hi Michael,

Quote

it is a ballpark value to give the reader a feel for the idea being communicated



IMO this is the crux of the issue. Just what is it that the general skydiving public/users would like to know about the gear that is out there.

In TSO C23b ( which I am most familiar with ), the Functional Tests and the Twisted Lines Tests are to be conducted at 70 MPH. The later versions of C23 have quite similar req'ments.

We accept that all of the gear on the market can pass these tests. So what about at 35 MPH? Why would I pick this speed? Well, what speed do you think a pilot chute gets into the wind when cutaway?

John Sherman says: In other words the pilot chute should "Jerk" you around.

My question to this is: At what speed should this occur?

Simple physics tells us that the actual drag/pulling forces vary with the speed at which the measurement(s) take place.

So my question is this: At what speed would people like to know the actual drag/pulling forces of various pilot chutes?

IMO once we know what we want to know, then we can begin to determine just what the values are.

I, personally, would like to see PIA fund a series of tests to come up with some independent values so that people can have more knowledge and understanding of the gear that they are using/considering purchasing. IMO these tests should not be TSO-types of tests, they should be tests to develop knowledge that is useful to the general skydiving public.

End of rant.

JerryBaumchen

Share this post


Link to post
Share on other sites
Quote

Quote

who thought that LOW DRAG RESERVE PILOT CHUTES were a good idea?



Easy answer.....people who make them!



So, please someone correct if I am wrong.We have tiny little LETHAL main canopies that are prone to malfunction.

We have tiny little container systems to fit these tiny little main canopies.

We have HIGHLY LOADED RESERVE CANOPIES because that is all that will fit into these tiny little container systems.

These HIGHLY LOADED RESERVE CANOPIES will kill you if you are unconscious or not on top of your game.

On top of that we have low drag reserve pilot chutes so that you can swoop your tiny little reserve canopy.

It's a RESERVE CANOPY. It is only there to save YOUR LIFE.

Does anyone else not see the dichotomy in this scenario?

Share this post


Link to post
Share on other sites
Quote

On top of that we have low drag reserve pilot chutes so that you can swoop your tiny little reserve canopy.



Um, don't think that's what they meant, by "low drag"...

Oh and some us still have those big ass rigs and canopies, hell I just up-sized my reserve last yr.
you can't pay for kids schoolin' with love of skydiving! ~ Airtwardo

Share this post


Link to post
Share on other sites
Well generally the reserve is freebaged so the drag of the reserve pilot chute is irrelevent. The canopy is fully clean and swoops beautifully. In fact I know some crw guys that have added dive loops to there reserve risers. But other then that you're pritty much spot on. You have done a fine job of summerizing the the adverage rig of the adverage exspereanced jumper. If I was to guess the adverage jumper would be better off if he went up one canopy size on both main and reserve. And he probable needs to go up two sizes on his container. And honestly neather the weight nor the size would bother then in the least. There really is no need for the container to end mid way up your back. Don't get me started on how many totals I've seen because they couldn't reach high enough on there back to pull the pilot chute. They thought they looked so cool walking to the plane but I was laughing my ass off when they came back in with their reserve in their arms on the first jump. Point is a larger container would actually be more comfertable then a little hard brick high on your back.

Lee
Lee
[email protected]
www.velocitysportswear.com

Share this post


Link to post
Share on other sites
Quote

Quote

On top of that we have low drag reserve pilot chutes so that you can swoop your tiny little reserve canopy.



Um, don't think that's what they meant, by "low drag"...

Oh and some us still have those big ass rigs and canopies, hell I just up-sized my reserve last yr.



Low drag is due to the small size of the pilot chute, due to it having to fit into the rig? Is that right?
Experienced jumper - someone who has made mistakes more often than I have and lived.

Share this post


Link to post
Share on other sites
Quote

Quote

Quote

On top of that we have low drag reserve pilot chutes so that you can swoop your tiny little reserve canopy.



Um, don't think that's what they meant, by "low drag"...

Oh and some us still have those big ass rigs and canopies, hell I just up-sized my reserve last yr.



Low drag is due to the small size of the pilot chute, due to it having to fit into the rig? Is that right?



As far as I know there is only one manufacture that changed the size of the reserve PC to accommodate the smaller rig.

Sparky
My idea of a fair fight is clubbing baby seals

Share this post


Link to post
Share on other sites
Quote

Low drag is due to the small size of the pilot chute, due to it having to fit into the rig? Is that right?



Absolutly not! Some of the largest pilotchutes in the industry have the lowest drag. My SRP will out drag any normal sized pilot chute made. If the design and construction are the same then your point is valid. Believe me they are not the same from manufacturer to manufacturer.

I am pushing PIA to require the identification of the effective size of the pilot chute in square footage. They can then be compared.

The solution to this problem is to require manufacturers to identify the maximinum allowable extraction effort for a given container. Additionally they should identify the effective size of a pilot chute which would do the job.

This guys problem had nothing to do with him being on his back. And yes Virginia there is a history of this happening. If this had been an AAD activation it would have been number 16 in the ground.

Get smart and stay away from these one pin cantilivered flap, over boxed rigs. They all have the same problem, each for a slightly different reason.

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