On Feb 21, 2:04*pm, Andy wrote:
On Feb 21, 2:04*pm, Tom wrote:

The following is the first of a series of newsletters to be sent to
subscribers to my popular newsletter.
This series of newsletters will review:
Accident causes.
FATALITIES PER THOUSAND
Gliders: Approximately 1 in 2,000
*Autos: *Approximately 1 in 6,000

Tom,

I don't doubt the numbers are horrible but can you please clarify
"FATALITIES PER THOUSAND"? *Per thousand what? *Is this registered
gliders, certificated pilots, hours flown, miles flown...?

thanks

Andy

I have the same question - what is the denominator? In fact there are
two denominators required since you also need to specify a time frame
(typically a year).

If the 1 in 2,000 is per glider pilot per year that would be a lot
worse for glider pilots than per hour or per operation - like takeoff
or landing, or per trip in a car. Most pilots spend a lot less time in
their gliders than in their autos and make a lot more car trips than
glider flights.

If the stats are per pilot then you are three times as likely to have
a fatal accident in your glider for an average person. If it's per
hour then you are 2-3 times as likely to have a fatal auto accident in
any given year.

Based on the number of people I know who have died in each activity
I'm betting Tom's stats are per person per year. I've known maybe a
dozen pilots who have been killed in gliders and can't recall a single
auto accident victim that I had met personally.

It also means that over a 40 year soaring career your probability of
being in a fatal accident is around 1 in 50, or 2% - assuming you fly
the average annual amount of hours over the entire period.

9B