PCA Discussion

[TomAiello 25]

Johnny,

On a Direct Bag deployment, do you think that attaching the bridle attachment point of the canopy to something inside the D-bag will yield faster overall inflation?

I think we're just at a point where we're disagreeing on theory here, and we'd be better served to go out and do some test jumps to see what the actual end result is. But if you're right on the theory, we ought to include a set-up like the one I'm asking about (D-Bag with attachment inside), as I'd think that would be one of the fastest possible systems.

Another thought: What do you think of doing a static line quad/tard, where the free hanging canopy is attached to the exit by break cord (via the attachment point), and you jump past it, leaving it at the exit?

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[JohnnyUtah 0]

Dude, it sounds more like you wanted to address addition factors that contribute random chance to the BASE jump. The variances you are talking about are not intentional (right?), and therefore those different configurations, happen in a random way (unless you have simply perfected a less than ideal behavior), and can repeat a less than ideal configuration exactly the same way time and time again. Perhaps some day we can control these factors better, resulting in a perfect pack job every time. In my explanation, I eliminated these factors, to focus on the one thing that you will never be able control (at least not in this life), AIR!!!

Quote

That is why I said
Say you fold and pack your parachute absolutely perfect, and during opening your pack tray is absolutely flat and still, and the wind conditions are totally calm.

Did you read that part?

Let us go to a molecular level. There is and will always be a part of the equation that you will never be able to control. Air molecules!!! The alignment of air molecule in one cube foot of air will be different than the alignment of air molecules in another cube foot of air. This is the nature of a gas. Air is matter in a gas form. If you understand physics, then why do you not understand this?

The way those air molecules bump into the fabric and lines during opening will always be different on every jump, because those air molecules will always be aligned differently within that section of air that the parachute is opening in.

(Unless it is the year 2250 AD and man has invented a chamber big enough to BASE jump in that will align gas molecules in a perfect array.) Instead of doing that, I think man should just build a bigger bridge.

Quote

Skin said
On a side note...Why is it that every time I see a photo of you the pic is of your ass?

Actually my post that you replied to, has a picture of me jumping from a helicopter at Squaw Valley during the Blade Running 1998 event, where you can see my face but not my ass. If you are a guy, I would appreciate it, if you would not focus on my ass. Thanks!

Have Fun, Don't Die!
Johnny Utah
My Website
email:[email protected]

[JohnnyUtah 0]

Quote

Tom said
On a Direct Bag deployment, do you think that attaching the bridle attachment point of the canopy to something inside the D-bag will yield faster overall inflation?

I do not know.
One big advantage to a d-bag, is that the canopy comes out of its containment device sooner, which allows it to spread out quicker. Keeping this in mind, it might be a mute point to anchor it. A danger that I can think of right now is: if the canopy is anchored to close to the exit point, it would have more chance of snagging on the object. Maybe we could put some kind of length between the attachment point and the anchor inside the d-bag. We will have to test that, and you can be the guinea pig if you want to.

Quote

Tom said
Another thought: What do you think of doing a static line quad/tard, where the free hanging canopy is attached to the exit by break cord (via the attachment point), and you jump past it, leaving it at the exit?

What the heck!! What kind corn pops have you been eating Tom? Just kidding.

If you were to use a short S/L, it may result in a higher off heading opening, with an increased chance of object strike. We could call that a tard to the second power.

On a roll over (McConkey Flip), if you used a S/L as long as your hanging canopy, allowing the canopy to still hang freely so you could control the heading, I think it might give you some altitude gain with no disadvantages. I would like to try this one.

Have Fun, Don't Die!
Johnny Utah
My Website
email:[email protected]

[Treejumps 0]

Johnny,

Your explanation of air molecules is irrelevant, and really quite petty. I think what Tom has been saying is that the assertions you have made fly in the face of some generally held truths about BASE canopy deployments. Suggesting that Tom's short time (?) in the sport somehow makes his technical knowledge lesser than yours is about as silly as suggesting his much greater jump numbers somehow ameliates your knowledge.

You've made some assertions about ultra low deployments based primarily it seems, on Anderson's ladder truck jump. Unless you have real data to back up your assertions, and I don't think that 1 or 10 jumps is a valid data pool, they are merely assertions, which by definition, are not factual.

So rather than try to run Tom down to make your newly stated assertions seem more plausible, back it up with real facts. Otherwise I am inclined to believe the empirical data that supports the current theories on PCA's, (and other low deployment methods) which is to say that hanging all of one's body weight under a canopy suspended at the bridle attachment is probably not the quickest opening nor highest quality deployment.

Just cause someone says it, don't make it so.

Tree

[JohnnyUtah 0]

Tree,

This thread started by me telling a story about a unique jump I witnessed. That is all I wanted to do. I thought the BASE community would be interested to hear about it. Tom asked me to elaborate. So I gave him that courtesy. In my elaboration, I pointed out, that testing needed to be done (I had this idea months ago). I have said testing needs to be done throughout this whole thread.

My initial elaboration was challenged by Tom. I did not ask for this debate and I would like this debate to end, especially now that you have degenerated it.

The air molecule explanation is totally relevant to every BASE jump that ever happens, though it is a minor factor. Whether you think so or not. I initially tried to explain it in more layman terms, but Skin did not understand. So I elaborated further for him. Sorry if you did not understand it. It is just science, nothing personal.

This thread may have started with a story about an ultra low jump, but I have made no assertions about ultra low deployments. My assertions resulting from TomÕs debate were about anchor strength affecting inflation rate. I plan to do all my test jumps from the Perrine Bridge.

You can believe whatever theories you want, but you have made false accusations (re-read the thread).


Tom,
I am truly sorry if I came across as coming down on you. I was just trying to give you some constructive criticism. I also gave you some great compliments too. Tom, I do like you and enjoy jumping with you. I hope for you the feeling is mutual.

Have Fun, Don't Die!
Johnny Utah
My Website
email:[email protected]

[TomAiello 25]

All right guys. Obviously Johnny and I have some disagreements about some relatively minor technical points that are really only going to be important on a small number of (fairly advanced) jumps.

That doesn't mean that we think each other are ignorant, stupid or inexperienced. It just means that our respective experiences have led us to different conclusions.

I'd be very interested in going out to the bridge with a video camera and some measuring devices and trying to figure out which of our approximations is closer to the far more complex reality. That way we can get some hard data that will be useful in keeping ourselves and others safe. All we're accomplishing here is burning up electrons (and perhaps amusing Tree ).

Quote

Tom, I do like you and enjoy jumping with you. I hope for you the feeling is mutual.

It is.

-- Tom Aiello

[email protected]
SnakeRiverBASE.com

[Treejumps 0]

Comments such as "Sorry if you did not understand it. It is just science, nothing personal" are what got my knickers bunched up in the first place. Very condescending, as were many of the things you said to Tom. It doesn't help to have a bunch of knowledge if you piss people off trying to share it. No one is the single authoruty on any of this stuff, and trying to sell yourself as such never does justice. Relax, share, and enjoy. Gotta go jump now.

Cya

PS: I still love you Johnny.

[Zennie 0]

And for the record I love both of you guys.

- Z
"Always be yourself... unless you suck." - Joss Whedon

[Skinflicka 0]

Johnny,

Thanks for the reply. I guess we'll have to agree to disagree over whether the events in gases at a molecular level are actually random or merely appear random through limited observation.

"If you understand physics, then why do you not understand this? "

C'mon man there's no need for that kind of condescension. My physics is just fine and the penomenon you're talking about (Brownian Motion) isn't really relevent. The microscopic effects of gas are not required in all cases to describe the macroscopic effect when the model has been reduced so extensively and over simplified. That was kind of the whole point of my post. Your assertion that air remains uncontrollable seems kinda odd given that you are a BASE jumper. What does a parachute do? House the magic levitation pixies?

There's a lot of ego in this game and a ton of bad things to happen. In fact, it can be a pretty miserable activity to be involved in. It would help if people kept their sense of humor and cooled their boots a little (and that comment is not directed at you, Johnny). This is entertainment afterall. It's just a game. It's no more important than that. We're not ambassadors for the human race. We're just a little nuts. Pretty trivial.

I'm sorry if the terseness of your response was initiated by the butt gag but I looked at the picture again and I definitely see the helicopter but it still looks like your ass.

I fully expect a response to that last rather offensive remark but hey, write something that puts a smile on everyones face, make me look like the asshole I am and enjoy the feeling as people sit at their computers, nodding their heads in agreement and murming "get him, Johnny".

We all need something to smile about.

Spread the love, Johnny.

Skin (Now and forever a Johnny Utah fan).

$kin.

Prizes to anyone who gets to read my posts before Mr Aiello's son, Tom deletes them.

[Treejumps 0]

"magic levitation pixies"

You made my day with that one. Very nice work indeed.

Tree

BASE610, Skinflicka FAN1

[BASE813 0]

skin stop posting and start working on getting your arse here! there are things to do and women and skydivers to insult!

put away your league of gentlemen tapes and baby oil and get your arse to the homelands!!

Be safe scablicker...........

Love ya work!!!

M

[DexterBase 0]

I have a favor to ask. This is a potentially productive thread. If we let it degenerate into bickering and semantics, it will get locked.

Technical threads are relatively infrequent here, especially ones where there are several very experienced jumpers contributing opinions.

Lets try to keep them open and promote a friendly environment here where people can feel free to post questions without fear of being flamed.

After all, when all the dust is settled, we're all family here.

[mnischalke 0]

I echo that favor.

I would hesitate to call much of this post a "debate." I prefer to think of it as a roundtable of discussion on some interesting and thought-provoking issues.

Still listening...

mike

Girls only want boyfriends who have great skills--You know, like nunchuk skills, bow-hunting skills, computer-hacking skills.

[ernokaikkonen 0]

Quote

The voodoo involved in "random" off headings initiated by the packjob is due to variation from the ideal configuration within our pack jobs. We vary slightly each time we pack. The way that the physical system (jumper, packjob, conditions, timing etc.) reacts is not random. It is very precisely defined by the laws of physics but the system is so large and complex that we haven't fully figured out the levers and triggers yet. I believe that the factors are indeed controllable.

Emphasis mine.

I believe that the opening of a parachute is governed by the "chaos theory", or "sensitive dependence on initial conditions". Meaning that no matter how carefully the parachute is packed, there is always an apparently random element involved. This "random" element may be triggered by something as small as the creases in the parachute fabric, or having the lines in just a couple millimeters in the wrong place; in short, I believe that bad openings may result from packjob variations so small that it is not practical to control them.

I don't think anyone is going to iron their parahute to improve openings.

Quote

I'd hate to call off the dogs in the search to discover the perfect packjob. We're not there yet by any means.

I agree. I'm sure there are ways to improve to current methods, but it is my belief that it is impossible to completely remove the "random black death"-factor from a packjob, just as it is impossible to make an accurate weather forecast for a date one year from now.

What I said here was basicly posted already by others, but I didn't see anyone mentioning the chaos theory, which in my opinion plays a large part in parachute openings.