On Tuesday, July 9, 2013 11:27:09 AM UTC-7, Evan Ludeman wrote:
On Tuesday, July 9, 2013 1:28:13 PM UTC-4, jfitch wrote:

On Tuesday, July 9, 2013 9:06:07 AM UTC-7, Evan Ludeman wrote:



PowerFlarm saved us from a probable fatal midair at Hobbs.















Thanks to everyone who has equipped their gliders with flarm.















-Evan Ludeman / T8







In the last 20 years, there have been 2 fatalities reported to the NTSB in glider-to-glider collisions. One in competition, the other not (ridge flying). Most of this period is without the benefit of Flarm. In both cases had both gliders been Flarm equipped the accident probably would have been avoided. Nevertheless, it remains statistically a very rare event. If safety is your concern there is more fertile ground to plow.







Disclaimer: my glider is PFlarm equipped and I have 20/15 vision in both eyes.



Cast your excellent vision on this sometime, please. It's 20 years old, unfortunately still very relevant. Bruno speaks for me on the comparison of auto and glider safety.



http://www.dg-flugzeugbau.de/safety-comes-first-e.html



FWIW, I agree (it's obvious to anyone that takes the time to look) that mid air risk is second order to launch phase, landing phase and terrain collision accidents.



Different types of risk respond to different risk management approaches and what works (training, judgement) for these other types of accidents just doesn't work as well for mid air avoidance. It's a sensory limitation. We don't have 4pi steradian vision and we aren't very good at picking up targets that are on a direct collision course. Happily, flarm does these things pretty well. Good on you for installing flarm.



regards,

Evan

That is an interesting article, but only tangentially on point.

Soaring is (compared to automobile travel) statistically dangerous. Glider-to-glider mid air collisions are a negligible part of that danger. Concentrating on them distracts from the much larger dangers. However, your point about mid air collisions being intractable to training is valid. Here is a risk that - with the mere expenditure of $2000 by every glider owner - can be largely eliminated. Just don't fool yourself into thinking you are much safer as a result.

Look at the numbers. I believe we have around 10 - 15 fatalities a year in the US in soaring. Let me pick 12 as a average for the sake of discussion. That means that in 20 years, of 240 people that died, just 2 are from glider-to-glider mid air collisions. Eliminating those you still have 238 fatalities. You are reducing your risk by less than 1%. Now I am aware that a particular misfortune that befalls me is not made more bearable by its statistic rarity. Nevertheless, those are the numbers.

I installed the PFlarm mainly for two reasons: peer pressure and as an in-flight entertainment system. Safety concerns were a distant third. I will though, turn hard right if I see you coming on my entertainment system!