"Roger Halstead" wrote in message
...
On Thu, 04 Mar 2004 13:34:49 GMT, "Gary Drescher"
wrote:

"Dennis O'Connor" wrote in message
...
This discussion has had it's silly moments... I will simply note that
adding
the instrument rating will result in a decrease in your insurance
premium...
I will let the rocket scientists in this discussion ponder the
implications
of that...

If your implication is that the insurance companies have found that an
instrument rating improves safety, that doesn't actually follow. It
could
be that the rating is diagnostic, rather than causative, of above-average
safety. You can't tell just from the correlation.

It's a very simple relationship.

Yes, it's fairly straightforward.

The insurance companies do not give a break unless they figure they
are going to save even more money.

Yes. So if they give a break to instrument-rated pilots, they've concluded
that instrument-rated pilots, on average, are safer than others. And let's
assume, for the sake of argument, that their conclusion is correct.

That follows directly that if they give pilots with an instrument
rating a cheaper premium they figure the odds are they will have to
pay out less due to that pilot being rated.

No, the "due to" part is precisely what does not follow. A better average
safety record on the part of instrument pilots does *not* suffice to show
that getting the rating improved their safety at all. Even if instrument
training has no effect on safety--or even if it has an overall negative
effect on safety (say, due to encouraging riskier flying than would
otherwise occur)--it's still possible for instrument-rated pilots, on
average, to fly more safely than others (which would still motivate an
insurance-premium discount). That can occur if, for example, more-capable
(and safer) pilots are much more likely than others to acquire the rating in
the first place. So as I said in my previous post, getting the rating could
be a diagnostic indicator of being a safer pilot, even if it doesn't cause
any improvement in safety--in fact, even if it has the opposite effect!

Therefore, to ascertain what effect instrument training has on pilot safety,
we need more information than just a correlation between the rating and
safety. (If I had to guess, I'd bet that instrument training does increase
safety. But that's just a hunch, not something that's derivable from the
available data.)

--Gary

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

--Gary

denny