base736

In fact, GPX might also be worth supporting directly here. It seems to be quite common. Tools like GPS Babel make it unnecessary to support everything, but the basics would be nice -- anybody have another format that they feel is a "must have" for skydivers?

Thanks for the data, and for the idea!

I'm in the finishing stages of putting together an easy-to-use piece of software for graphing GPS flight data. As part of this, I'd like to be able to import NMEA data, but unfortunately I've got none on hand. At any rate, it'd be nice to have data from a variety of devices to ensure that I can import it from the common units.

If anybody has a jump or two of raw NMEA data that they wouldn't mind sharing with me, I'd love to make sure that this software is compatible with the GPS you use.

Thanks, all!

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If this is true, why would they do that instead of setting up a tad back and fly vs sink the suit?

Same reason you set up conservatively with a canopy -- because it's a lot easier to lose altitude in a wingsuit than it is to gain it.

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I have some really funny video buried somewhere in my historical collection. There's a jumper standing out on a diving board of rock at a popular tourist overlook (which is illegal to jump), during the day, with no rig. Another jumper is filming him as he stands out there, and you clearly hear a kid in the crowd say "I hope he falls!"

On the hike up to a local E a couple of summers ago, we ran across a group of kids from a camp or something. We were decked out in our best Dainese fishnet, so the kids wanted to know what we were up to. When we told them, this one girl, ten years old or something, points right at me and says, "You're going to die." Just like that.

That was this jump. So much for her future as a clairvoyant. I wasn't even hurt.

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“Sigh” Finally... thank you Mac. I thought I was the only person reading this posting and thinking wtf. There is no roller coaster effect from skydiving or BASE. On a roller coaster, the “roller coaster effect” isn’t felt as you’re increasing speed and moving downward before a loop. It is felt as you are hitting the loop and moving upward against the force of gravity (g-forces).

Then your experience of roller coasters is simply different from mine, and from that of a lot of other people on the thread. Whenever I've heard "that roller coaster feeling" talked about, it's been the feeling as the ride makes its way over a crest. The same feeling can be had sitting in a car as it comes over some crests in the road. I suppose some might feel a similar sensation with acceleration in other directions, too -- I expect it's caused by any change in the forces suspending the internal organs.

That you don't feel it on a BASE jump -- I never have -- doesn't mean everybody else is retarded for saying that they have.

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Can someone recommend a good (cheap) online retailer for Dianese?

Dainese is good, but never cheap. For what is apparently a very good jacket at a substantially lower cost, though, you might look into Velocity Gear.

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so is the meaning you well not get kill by driving a car or get hit by a car or die from cancer, have heart attack,

You should read more carefully. The risks you're listing are not risks you choose to take -- they are the ones you are born into. To the extent that they are elective (if, for instance, you're increasing your risk of lung cancer by smoking like a chimney) then you certainly wouldn't be alone in modifying your lifestyle to increase the odds that you'll see your kids graduate.

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stop living by meaning for some is stop base jumping

Those people have a problem. Whether your chosen passtime is watching TV, or playing World of Warcraft, or BASE jumping, if you're blind to the fact that the world offers so much more, that's not something you should be proud of.

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what abut all the mom and dad the was kill in 911, so we all should stop working or stop living.

Apples and oranges. Setting aside the fact that the probability of dying in a terrorist attack at work is vanishingly small compared to that of dying on a BASE jump, BASE jumping is a strictly elective risk.

... There's a whole world of cool stuff to do out there, much of which is less risky than BASE. To go from "stop jumping" to "stop living" is more than a little melodramatic.

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what if you get kill base jumping, will you mom and dad care less because you are older, if you son like to start base jumping at age 16 and get kill well that hurt you more than he waited tell he is 21 and than get kill.

The difference here is that your parents are not dependents. If I have kids, then die jumping (a very risky sport I have chosen to participate in) when they're five, not only have I left my children without one parent, but as a bonus, I've left my wife without my support, and without a second income, at the same time that I've left her in sole custody of some kids. That we were supposed to raise.

There are some good arguments for continuing to jump, if you so choose, after you have kids. They are not the ones you've given.

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First of all, I doubt whether a 4 year old brain can compute the concept of basejumping being fun instead of dangerous.

That's interesting, because when I looked at the picture I was thinking exactly the opposite -- it surprises me a little that a kid whose parents were excited about the jump would be so scared of the same thing.

You're complicating my perfect world, ParaFrog!

Clearly "Building" is the best first object. That way, if you die on your first BASE jump, hey, at least you've jumped a building, right?

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On what level, if even in the same realm, would you BASE jumpers actually compare a hot air balloon jump to a BASE jump? (of any height) 10x more nuts?, 100x? 1000x?

A balloon jump (and, in many ways, a helicopter jump) shares a lot in common with a BASE jump with respect to how quiet it is at the exit point, and the complete absence of a relative wind at exit. I recall the first being a big part of the rush in a balloon jump -- it seems like it's much more difficult to do something like launch into thin air in the absence of loud noise (engine noise, or some guy yelling "3-2-1-go").

The two sports differ rather astonishingly with respect to both the visuals and (especially important to understand) the risks that follow.

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"Is that a base-rig?"
"No officer, I' am coming from my dropzone. This is just a 'parachute'! "

Not that I doubt that this could happen, but has this ever actually happened to you, or is it more like that scenario where the plane breaks in half, some woman screams "Please, save my baby!" as I'm gearing up, I grab the kid, etc., etc., and land in the middle of the Superbowl in front of a roaring crowd?

The part where the officer knows the words "base" and "rig", and doesn't just bust your ass on the spot for having a parachute seems questionable.

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But the stakes are higher now as besides basic security concerns it's unconscionable we dangle BASE jumping so freely in front of a larger than it used to be crowd of the young and impressionable. If you don’t agree with that then it follows you either believe BASE is an everyman's sport, or worse, you just don’t give a shit when someone is injured, maimed, or killed.

I believe that it is each person's right to choose their own course in life, inasmuch as that course doesn't hinge on stopping others from doing the same. I also believe that BASE is among the most beautiful things I've experienced, and that such things should not be relegated to the shadows.

While the idea of people getting injured or killed bothers me, the idea of hiding something so remarkable in an ill-conceived attempt to protect people from themselves bothers me even more.

Such data would be impossible to interpret without a parallel survey of what types of rigs people are jumping, and perhaps how frequently they jump. Not only that, but the numbers -- particularly if one is looking for information on newer gear configurations -- are so low (despite being tragically high) that I expect any interpretation of trends within them would be dubious at best.

If you could quantify injury rates, you might have something more valuable...

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Sure the guy who went it would probably like to say he is a super hero and went in with just a PC out but I doubt that is true.

If a guy impacts at high speed, gets up, dusts himself off, and walks away, then he's a god or one absurdly lucky mortal.

If a guy impacts at high speed, is immediately attended to by level-headed friends, is transported and treated by highly skilled professionals, and is walking weeks or months later, then you should look to those other folks -- the friends and the doctors -- if you want to find hero material.

Thanks again to everybody who did what had to be done when I got myself into trouble. That really can't be said enough.

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Surely this can only help in extracting the canopy from the container?

It will probably extract the canopy more quickly. What would lead you to believe (and I say this not to question your intelligence, but to suggest a way of thinking about these things) that extracting the canopy as quickly as possible is always a good thing? And that it comes at no cost?

Large pilot chutes don't necessarily provide more immediate drag -- they take a moment longer to unfold. Even if they did, or when they ultimately kick in, extracting the canopy too quickly leads to all sorts of ugliness, much of which can be traced back to distortion in the packjob as it's extracted. It's called a deployment sequence for a reason -- doing it all at once does real damage to performance.

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please for the love of God
this was a BS jump nothing happend
[blah, blah, blah]

Mmm. I love the taste of piss and cornflakes in the morning.

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To get really technical, what is relevant here is the "power" of an impact [...]

Can you support that with a reference of some sort? My understanding has always been that in hard collisions, kinetic energy at impact is the relevant factor, while force is important for more extended collisions.

The rationale goes as follows... As a warning, anybody with no interest in discussing the "why" of that should stop reading now. The below will almost certainly not make you a better jumper.

There is a certain minimum amount of energy involved in, say, breaking a particular bone. Undoubtedly, one can expend more than that to do the same damage less efficiently, but there is some way which takes the least energy, and that minimum is not zero.

For more extended impacts (a proper dive, or a bungee jump, as opposed to landing in a seated position), a lot of mechanical energy is lost to heat, and it's more useful to talk about the force applied to a part of the body (though the above argument still holds).

Either way, a certain amount of energy is required if one wants to break the bonds that keep the bone/spleen/ass cheeks together. You can apply half that amount as quickly, or as cleverly, as you like, making the power arbitrarily high, and it still won't do the trick.

Edit to add: Could be we're basically talking semantics here. It's not clear to me that one could manipulate force and power independently, so that it may be possible to use either in the case of an extended impact.

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Impact force, is directly proportional to speed.

Perhaps (for certain types of "impact"). Damage done in a sudden impact, however, is more closely related to the amount of energy dissipated -- that is, how much energy is available to blow your ass cheeks apart, and how much is left even after that to do the sorts things that water shouldn't do without first buying you a drink. The energy dissipated is given by the kinetic energy at impact, which (as noted above) is proportional to speed squared.

Which is to say, as in a previous discussion, that (for sudden impacts, such as hitting water at high speed) twice the impact force sucks, but twice the impact force over twice the distance sucks even more. The same may not be true of more extended decelerations taking place over seconds.

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kinetic energy is proportional to speed * mass, right? Speed is determined (partially) by height fallen, yes, but air resistance plays a large part of what the impact speed would be from any given height.

Speed squared. And the difference due to air resistance over the first 100' would be exactly half a metric smidgen.

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impact force is a measure of SPEED, not distance fallen. the difference between 80' and 110' is very little, as the difference between 110' and 150' is very little. a few FPS.

Edit: Bad calculations deleted -- my bad. You are, of course, correct here, except that the damage done in an impact is proportional to the kinetic energy, not the speed, which is proportional to the height fallen.

... And just like that, the conversation never happened. Nothing to see here, folks. WTF?

Using my super-duper reverse-engineering skills, I'm going to guess that the original post was about a McConkey from low, low, low? Why delete it when others still might learn from the thread?

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http://www.coreyrich.com/

Thanks for the link! That is some sweet photography.

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no bungees, just steel cable; big disfference aparntly.

My bad. Replace "bungees" in the above with "thing that does the work". By any name, unless the thing that does the work does all or nearly all of it in the first four metres, 42 g's is out of the question. If one assumes that the 50-metre cranes aren't merely for show, so that the work is done more-or-less evenly over most of that distance, then the ~5 g estimate holds.

Oh, and I'll call BS on the 42 g's. To reach a maximum altitude of 150 m, one needs to leave the catapult at about 55 m/s. To accelerate to that speed at 42 g's would take less than 4 m. Admittedly, the acceleration isn't constant, but given that the towers were ~50 m tall, the average acceleration would be about 3 g.

Another edit... Better estimate: if we assume the bungees act as Hooke's-law springs (we could do worse), then the numbers above give an initial (ie, maximum) acceleration of about 6 g.