Cirrus... is it time for certification review?

"Peter Duniho" wrote

A quick NTSB database search shows in the last six months 4 accidents (2
fatal) involving a Cirrus SR20, and 52 (5 fatal) involving a Cessna 172. The
SR22 was involved in 7 accidents (2 fatal), while the Cessna 182 was involved
in 36 (6 fatal).

Clue - Look at fleet size, then adjust for that, and come back with some more
meaningful statistics.

How many bazillion C172's are there out there, vs. Cirrus?
--
Jim in NC

"Morgans" wrote in message
...
Clue - Look at fleet size, then adjust for that, and come back with some
more meaningful statistics.

The fleet size isn't nearly as relevant as total flight hours for the flight
over a span of time. And yes, I agree that the data is missing. However,
none of you have provided alternate data to support the claim that the
Cirrus is actually worse. And at first glance, the total number of Cirrus
accidents is MUCH lower than for Cessna accidents, which is exactly what one
would expect given the difference in fleet sizes.

Clue: when you are making accusations, the burden of proof is on YOU. If
you're going to claim that the accident rate is abnormally high, you need to
provide data to support that claim. Suggesting that the defense has
insufficient data isn't meaningful.

Pete

Morgans wrote:
"Peter Duniho" wrote

A quick NTSB database search shows in the last six months 4 accidents (2
fatal) involving a Cirrus SR20, and 52 (5 fatal) involving a Cessna 172. The
SR22 was involved in 7 accidents (2 fatal), while the Cessna 182 was involved
in 36 (6 fatal).

Clue - Look at fleet size, then adjust for that, and come back with some more
meaningful statistics.

How many bazillion C172's are there out there, vs. Cirrus?

One thing these figures seem to say is that 50% of SR20 accidents are
fatal, but only 10% of 172 accidents are. It is only a bit better if
you compare both Cirrus and Cessna types. The parachute should make
Cirrus accidents more survivable, not less.


John Halpenny

On 31 Oct 2006 17:28:21 -0800, "John Halpenny"
wrote in .com:

One thing these figures seem to say is that 50% of SR20 accidents are
fatal, but only 10% of 172 accidents are. It is only a bit better if
you compare both Cirrus and Cessna types. The parachute should make
Cirrus accidents more survivable, not less.

What's the SR20's stall speed compared to the C-172? The kinetic
energy expended in a mishap increases exponentially with the square of
the velocity.

"John Halpenny" wrote in message
oups.com...
One thing these figures seem to say is that 50% of SR20 accidents are
fatal, but only 10% of 172 accidents are.

As I pointed out previously, there aren't enough SR20 accidents (or even
SR20 and SR22 combined) to make any valid statistical conclusions. The
statistical error on the sample size exceeds the number of samples.

Pete