On Saturday, January 18, 2014 9:55:20 AM UTC-8, son_of_flubber wrote:
On Friday, January 17, 2014 10:38:48 PM UTC-5, Frank Whiteley wrote:

1/1800 just kind of looks about right given what we know about the pilot population.



Thanks for this well-considered number, it completes the picture. To relate it back to the context of my original point...



1/1800 equates to a .18% chance of glider related fatality in each year of flying. Over ten years that would be .18 X 10 = 1.8% cumulative risk over 10 years (say 2%).



Side by side with my original mortality prognosis (individual based on my age and health status):



I have a 19% chance of dieing from all other causes in the next ten years..



I have a 2% chance of dieing in a glider in the next 10 years.



Say a 10:1 chance of dying of natural causes before I die in a glider. I'm good with that, but I will keep looking for ways to improve my odds.

Our club got into this topic a couple of years ago regarding the old statement of the drive to the airport being the most dangerous part of a glider flight. I went about the analysis a little bit differently, but came to about the same number for gliding. Per the NHTSA statistics, in 2011, auto fatalities were 15.28 per 100,000 (1/6,545) licensed drivers. Using this set of data leads to a 0.015% chance of becoming an auto fatality statistic. Bottom line is that flying a glider is more dangerous than driving a car, but in a risk/benefit assessment, the risk of gliding is (generally) fully acceptable, and the benefits (enjoyment, challenge, etc) far more than offset the risk. Similarly, auto fatality statistics apply to the average commuter, not race car drivers, who have their own risk/benefit analysis which leads them to accept a higher risk for participating in their sport.

The risk of a fatality is not the same as the likelihood. We expose ourselves to the risk of an auto fatality much more frequently than we do to a gliding fatality. For the auto side, there is a low risk, which coupled with the frequency still leads to a low likelihood of a fatality. For soaring, the risk is much higher (although still low), and the frequency of exposure is less. I haven't worked out the likelihood for soaring, but it is probably less than the risk might lead one to think.

Of keen interest to me, just recently having cataract surgery, the risk of a major complication from the cataract surgery, up to and including blindness, is about the same as a soaring fatality (in the analyses overall). Having had the surgery, I wouldn't try to keep flying without having it, now that I know the impact of cataracts on vision. Likewise, so long as I take care of pre-flight, in-flight and post-flight tasks in a safe manner, I'm confident that risk of a fatality while flying remains low - for me. Not wanting to judge, I've watched other pilots do - or not do - things that makes their risk of having an accident, fatal or not, much higher than 1/1800. (Note: the risk of a group is essentially an average for that group. For some members, the risk is much less, and for others, much higher. So, for one pilot the risk might consistently be 1/500 and for another 1/2500. And, the risk can vary from flight to flight, depending on a number of factors. Bottom line - the averages help, but don't tell any one pilot what is going to happen any one time, or over their flying career.)

It is interesting to note that since 1994 the auto fatality rate has been consistently declining primarily related to auto and road safety measures, not better driving habits or heightened driver safety awareness. Maybe a message there for soaring safety, maybe not, since so many fatalities occur on takeoffs and landings. But driver error is as a contributor to auto fatalities, and some auto safety improvements have led to fewer fatalities regardless of driver error.

Another 2 cents worth.