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annna

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Regarding the quoted paragraph below (from some groovy article online) - does anyone have any other kinda stats on the question we're always getting asked by friends, family, work colleagues - 'isn't it really dangerous ?!'.
I usually mix up my reply to avoid the terminal boredom associated with answering the same question over and over - sometimes i'll say Yup, could die tomorrow its the most dangerous sport EVER and sometimes i'll tell people i'm more likely to die getting ravaged by a badger BUT
the stats down there about if you jump 17 times in a year you're statistically at the same risk of dying jumping as dying in a car crash kinda surprised me !

regards, Anna x

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"The big question is always, "How dangerous is skydiving?" Each year, about 30 people die in parachuting accidents in the United States, or roughly one person per 100,000 jumps. Look at the US Skydiving Incident Reports to get an idea of the types of problems that lead to fatalities. If you make one jump in a year, your chance of dying is 1 in 100,000.
How does the fatality rate in skydiving compare to other common activities? Since most adults in America drive cars, let's compare skydiving to driving. Roughly 40,000 people die each year in traffic accidents in the United States [ref]. That's 1.7 deaths per 100 million vehicle miles. Therefore, if you drive 10,000 miles per year, your chance of dying in a car wreck in any given year is something like 1 in 6,000. In other words, we accept a higher level of risk by getting into our cars every day than people do by occaisionally skydiving. You would have to jump 17 times per year for your risk of dying in a skydiving accident to equal your risk of dying in a car accident if you drive 10,000 miles per year. "
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You have less chance of dying if you jump 170 times a year than if you jump 17 times a year.



Correct! but only if you first you make an implicit assumption

For bonus points and a chance to win the special 14 year-old prize that Skymama is giving away, what is the implicit assumption underlying that statement?

Based on input from Remster this was edited to qualify the "Correct!" interjection.
AMDG

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http://entertainment.howstuffworks.com/skydiving8.htm

Here's the link to the quote.
I didn't think it sounded too correct, but then - that was based on pure gut feeling !

I guess there must be threads in the past with some more reliable stats - i'd be interested to a link to them if anyone knows.

On the other hand - i hate stats !!! What am i talking about !! Its very sunny - think i need to skive off and go jumping ;-)

anna

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You have less chance of dying if you jump 170 times a year than if you jump 17 times a year.



Correct!

Quote



And you base this on what exactly? If you state Correct then you must base that on data somewhere. Can you please provide it?

Carefull when making statements like that if you dont ACTUALLY have the information.

Remster

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Actually, the quote is pretty spot-on. Using 2000 USPA data of 32 fatalities and an estimated 2,244,165 jumps Tom B, in Jump! Skydiving Made Fun & Easy, presents a fatality rate of one death for each 70,130 skydives.

(Of course he doesn't go on to display a stunning lack of statistical comprehension, as the aforementioned site does, by qualifying it with If you make one jump in a year...)
AMDG

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...what is the implicit assumption underlying that statement?



There are procedures, based on r, for making inferences about the population correlation coefficient. However, these make the implicit assumption that the two variables are jointly normally distributed.

When this assumption is not justified, it's better to use the non-parametric measure of the Spearman Rank Correlation Coefficient.

Bottom line: Give actual values to variables.

;)

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Regarding the quoted paragraph below (from some groovy article online) - does anyone have any other kinda stats on the question we're always getting asked by friends, family, work colleagues - 'isn't it really dangerous ?!'.
I usually mix up my reply to avoid the terminal boredom associated with answering the same question over and over - sometimes i'll say Yup, could die tomorrow its the most dangerous sport EVER and sometimes i'll tell people i'm more likely to die getting ravaged by a badger BUT
the stats down there about if you jump 17 times in a year you're statistically at the same risk of dying jumping as dying in a car crash kinda surprised me !

regards, Anna x

*****************************************
"The big question is always, "How dangerous is skydiving?" Each year, about 30 people die in parachuting accidents in the United States, or roughly one person per 100,000 jumps. Look at the US Skydiving Incident Reports to get an idea of the types of problems that lead to fatalities. If you make one jump in a year, your chance of dying is 1 in 100,000.
How does the fatality rate in skydiving compare to other common activities? Since most adults in America drive cars, let's compare skydiving to driving. Roughly 40,000 people die each year in traffic accidents in the United States [ref]. That's 1.7 deaths per 100 million vehicle miles. Therefore, if you drive 10,000 miles per year, your chance of dying in a car wreck in any given year is something like 1 in 6,000. In other words, we accept a higher level of risk by getting into our cars every day than people do by occaisionally skydiving. You would have to jump 17 times per year for your risk of dying in a skydiving accident to equal your risk of dying in a car accident if you drive 10,000 miles per year. "
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1. Most skydivers jump more than 17 times a year.

2. Assume for argument's sake that the data are accurate. The 17 jumps correspond to something in the vicinity of an hour of "at risk" time. Driving 10,000 miles corresponds to something like 200 hours of "at risk" time.
...

The only sure way to survive a canopy collision is not to have one.

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;)so therefore it is more dangerous driving to the DZ than jumping at the DZ.



I'm sure you're joking here....but I hear too many people say that and they actually believe it. If anybody believes that driving to the DZ is more dangerous than jumping out of an airplane, they're incredibly stupid. When you step out of an airplane, YOU ARE DEAD UNTIL YOU DO SOMETHING TO PREVENT YOUR DEATH! I joke with my friends and tell them I'm a "dead man flying", but it's essentially the truth.

Of course, with AAD's, people can argue that you have a 99.9% chance of surviving if you do nothing other than turn on your AAD before the jump...well, they'd probably be right...but that's another issue.

We can't just say that skydivers are subject to X amount of risk by jumping Y times per year. It varies person to person. Who's more likely to get killed in the sport - a jumper that does 200 jumps a year, flies a large canopy at under 1:1 wing loading(and a reserve the same size), and has an AAD - or the guy that does 1000 jumps a year, flies a cross braced canopy loaded at 2.5:1(and a reserve at 2:1), competes in pond swooping, and does not use an AAD in their swoop rig? Of course, many people would say the second jumper stands a higher chance of getting killed in this sport, but again....it depends on the people. I, personally, would think the first jumper is more likely to be killed. The second knows their canopy intimately...and, let's face it, more people die under a perfectly good canopy than in any other situation.

Mike

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It's an absurd comparison. The only thing that's more absurd is the implication that skydiving is safer then driving a car. Well, skydiving might be safer then driving on a rain slicked highway, at twice the legal speed, while hopped up on a cocktail of at least 3 different illegal drugs.

Why even attempt to deny that skydiving is dangerous? Why are we trying to fool ourselves? Isn't the danger part of the appeal?

A fair comparison would be to compare a skydive to a short trip in a car, not driving 10,000 miles. However, when compared this way, we realise that skydiving actually is dangerous... which should be obvious. This clearly wasn't the authors point. He was trying to deceive. Why?


_Am
__

You put the fun in "funnel" - craichead.

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Re: ' the author was trying to deceive'

Are you trying to get some kind of conspiracy theory going ?! Bless, sure he was just trying to simplify something that can't be simplified - like me trying to put a statistic on my risk taking to placate my friends.

Cheers for all the input tho - have decided on my future reply for 'Isn't it really dangerous?'.
Yes. Next question.
And i will refuse to expound further !!

Is expound a word or did i just make that up ....
hmmmm

anna x

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Assuming the same exerience level overall, I would think, (just an opinion here) that they person who only jumps 17 times a year would have a higher level of risk per jump because they are not as current as the 170 jump per year person.

However in reality, I doubt there is much of a way to compare the overall risk taken compared between the two. Its like trying to decide if the overall marginal risk of the 17 per year jumper out weighs the total added risk of of the extra jumps. Something along the lines of:

17 jumps * (risk + noncurrency) is <, >, or = 170 jumps * risk


Pretty hard comparison to make honeslty.

I know I would probally not jump if I could only make 17 per year... just not enough time in the air.
~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

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Are you trying to get some kind of conspiracy theory going ?!



Heavens no. A conspiracy would involve more then one person acting togeather. I think those who believe skydiving is as safe as other common activities are deluding themselves - or they know better and are deluding others.

I don't know who wrote the quote you posted, so I don't know if they're misguided themselves, or are attempting to miguide others.

Skydiving is dangerous. Although we can, should, and do minimize the risks, it will always be dangerous. Honestly, I think that's a part of the attraction.

_Am
__

You put the fun in "funnel" - craichead.

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1. Most skydivers jump more than 17 times a year.




Most people who make a skydive make only one.


Another danger comparison I like to use on my non-skydiving pilot friends is that the chances of dying from making one skydive is statistically similar to that of flying one hour in a small airplane. It's pretty close for a C-172.

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1. Most skydivers jump more than 17 times a year.




Most people who make a skydive make only one.


Another danger comparison I like to use on my non-skydiving pilot friends is that the chances of dying from making one skydive is statistically similar to that of flying one hour in a small airplane. It's pretty close for a C-172.



I don't know if I would call tandem students skydivers. I know I sure as shit didn't think I was a skydiver after one tandem. I would say the same thing about aff.
~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

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It is true that, if an expert (D-license) and current skydiver jumps 17 times a year, he's safer over the course of a year than someone who drives 10,000 miles a year. Unfortunately, there are no expert and current skydivers who only jump 17 times a year.

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Food for thought: a WARNING on ParaGear opening page states that “approximately one jump out of every 20,000 results in death” and “On the average, Ram-Air parachutes are expected to malfunction once in 333 activations”. They claim the data comes from USPA reports.

All the stats that being published – do they include fatalities from jump plane crashes?

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1. Most skydivers jump more than 17 times a year.




Most people who make a skydive make only one.

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That is true, but these people are officially designated "Passenger" by the FAA.

Does a tandem jump count as one jump or two in recording the stats?

...

The only sure way to survive a canopy collision is not to have one.

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not even going to read the whole thread. sue me.

even my dumb ass knows this is a ridiculous comparison. skydiving is a perilous activity that demands a level of performance far exceeding that of driving a car.

maybe a better stat would be percentage and severity of injuries vs deaths resultant of incidents in both activities.
namaste, motherfucker.

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