The Killing Zone

[nigel99 144]

Hello All,

I was in an aviation bookstore the other day and came across the book "The Killing Zone - How and Why Pilots Die" by Paul Craig.

From the beginning of the book

Quote

We cannot live long enough to learn from every mistake. That is why it is so important that we get together and share our experiences so that we can learn, understand, and gain airmanship. Together we can attack and hopefully someday eliminate, the Killing Zone...

P.Craig
July 2000

It addresses very many of the same issues seen in skydiving time and again.

Experienced jumper - someone who has made mistakes more often than I have and lived.

[velvetjo 0]

One of the key concepts in that book is that a zone exists between x and y hours of experience where pilots are prone to fatal errors. It seems like there's probably a similar zone for jumpers too.

Out of curiosity, does anyone have any thoughts on the low & high end of this "killing zone" range for skydiving jump numbers?

Lance

[LouDiamond 1]

If you look at the USPA pie chart(s) of accidents/fatalities you will see that most are D license holders and or under a perfectly functioning canopy.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[pchapman 262]

It's hard to tell what the situation is without good data on "base rates". If a certain percentage of fatal accidents happen to jumpers with a B license, we need to know what percentage of active jumpers have a B licence. Then there's the issue of whether to judge on safety per jump or per time period. E.g., if one goes from doing 100 jumps per year to doing 400 per year, does one have to be four times safer per jump, to be considered an equally safe skydiver now, or not?

[nigel99 144]

Quote

If you look at the USPA pie chart(s) of accidents/fatalities you will see that most are D license holders and or under a perfectly functioning canopy.

I have not jumped for many years - but following DZ.com's fatalities it appears that the majority of bad accidents are landing related and would typically involve jumpers with less than 1-2k jumps but greater than 100. I have not done any rigorous research to back this up and I know of at least 2 incidents involving jumpers with >4k jumps (Tonto) and the one in texas with 10k or so jumps, but I do see these as exceptions.

Experienced jumper - someone who has made mistakes more often than I have and lived.

[velvetjo 0]

Thanks - it would also be interesting to know if the experience zone for serious accidents differs much from fatalities. Advances in medical technology (trauma centers, extension of 911 systems, EMT training) have made many serious accidents survivable today that could have been fatalities 20 years ago.

Another factor to consider is the experience level within a specific discipline - maybe that's a better gauge of the real danger zone nowadays. If, through SIM recommendations and BSR's, we typically delay a jumper from beginning more hazardous disciplines (swooping, CRW, camera, etc.) until they have a few hundred jumps, that seems to bump the whole curve toward higher overall jump numbers / experience.

Lance

[LouDiamond 1]

To get a better idea of how to look at this objectively, you have to look at the whole picture so to speak. I am sure they did the same with aviation hours and came up with an average to be able to throw a specific number out there like they did.

You can reference the USPA accidents HERE

and a summarized report here for 2009.


Break down by decade and year can be found here

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[nigel99 144]

Quote

To get a better idea of how to look at this objectively, you have to look at the whole picture so to speak. I am sure they did the same with aviation hours and came up with an average to be able to throw a specific number out there like they did.

You can reference the USPA accidents HERE

and a summarized report here for 2009.


Break down by decade and year can be found here

I just spent the last couple of hours collating the following attachments from the DZ.com database.

A few points:
1) I only included Europe and USA to save time
2) divisions are 1-250,251-500 etc. If a jumper was listed at 1000+ I put them in the 1000 category
3) I included tandem passengers and all but 1 suicide (suicide that I exluded did not have a parachute - whereas others did)
4) 2008 Europe appeared to have duplicate entries in a few cases so I excluded what I saw as duplicates.
5) The "unknown" number of jumps are normally experienced jumpers who were instructors or demo jumpers. Unknown is shown on the graph as the 0 jumps line.

I think it is pretty evident that most fatalities occur prior to 250 jumps.

Experienced jumper - someone who has made mistakes more often than I have and lived.

[pchapman 262]

Great stuff, thanks for the work put into that.

If you kept the original data categorized and ever had the time to go another step, I personally would like to see the same with:

- suicides left out since they don't represent accidental deaths
- the unknown jump number category moved off to the side with a separate category, so it doesn't visually look like it is part of the "under 250" region
- something similar could be done with "1000+" type results, although it may take a more sophisticated graphics program
- tandem passengers who are students - a bit debatable what to do there, but OK as is, since it is still a risk they are exposed to whether or not they have much control
- smaller categories at the lower numbers would be interesting to see -- It is perhaps more important to know whether someone had 50, 100, or 200 jumps, than whether they had 2000 or 4000

There's never one perfect way to display or categorize data, however. Different uses require different organization.

Thanks.

[LouDiamond 1]

Interesting data. How does it affect the results if you only compile it for the USA?

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[nigel99 144]

Quote

Great stuff, thanks for the work put into that.

If you kept the original data categorized and ever had the time to go another step, I personally would like to see the same with:

- suicides left out since they don't represent accidental deaths
- the unknown jump number category moved off to the side with a separate category, so it doesn't visually look like it is part of the "under 250" region
- something similar could be done with "1000+" type results, although it may take a more sophisticated graphics program
- tandem passengers who are students - a bit debatable what to do there, but OK as is, since it is still a risk they are exposed to whether or not they have much control
- smaller categories at the lower numbers would be interesting to see -- It is perhaps more important to know whether someone had 50, 100, or 200 jumps, than whether they had 2000 or 4000

There's never one perfect way to display or categorize data, however. Different uses require different organization.

Thanks.

I have my spreadsheet but it is not annotated - if anyone wants a copy let me know. It is probably quite easy to evolve the data.

I thought about suicides but then where do you stop? A surprising number of experienced jumpers deaths were people in their late 40's and older who died of medical complications - with the number of fatalities involved for people with over 1000 jumps this contributes significantly - much more than suicides or tandem pax.

It would be fairly easy to break it down further below 250. I believe you would want 1-25 jumps as there were a fair number of students who simply did things wrong (and were often female), 25 to 100 and then 100-200. Again while there were significant numbers of 100 jump wonders who died doing low turns, my feeling from collating the data was that fatalities in the 50-250 jump region were shared pretty evenly between young men doing low turns, and older men (50's+) who did not respond to an emergency correctly or quickly enough. I didn't break the data down though it was just a picture that emerged while gathering the data.

Experienced jumper - someone who has made mistakes more often than I have and lived.

[nigel99 144]

Quote

Interesting data. How does it affect the results if you only compile it for the USA?

I added both and didn't keep them separate, but the trend would stay the same. The European and USA figures are almost identical and the distribution was the same.

Experienced jumper - someone who has made mistakes more often than I have and lived.

[jim_32766 0]

Your graph should be used as a standard part of ground school training during AFF. It might help newbies to develop a mindset that surviving a few jumps does not an expert make.

The meaning of life . . . is to make life have meaning.

[kallend 1,646]

If only we had data for the number of active skydivers at the various experience levels.

...

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

[nigel99 144]

Quote

If only we had data for the number of active skydivers at the various experience levels.

I've been thinking about that and while I am sure that many people stop skydiving prior to 500/1000 jumps. If you could normalise the ratios I still think that it would peak below 500 jumps. It is possible that the peak would move to >2500 jumps as there are lesser jumpers but only if you included the medical condition related fatalities (already included in the graph/data above). If the peak moved in that direction I would be inclined to say that age rather than number of jumps would be the contributing factor.

I think that it still holds true and goes to show that as you gain experience your likelihood of dying due to YOUR mistakes is drastically reduced. Below 500 jumps you are more likely to kill yourself skydiving than for any other reason.

Experienced jumper - someone who has made mistakes more often than I have and lived.