On Fri, 27 Oct 2006 18:22:34 -0000, Jim Logajan
wrote in :

Larry Dighera wrote:
However, if you have, for example, an engine failure at 400' on
departure, the CAPS is not an option.

My point is, that CAPS is not an option at the times it's needed most:
below 920'. So to characterize the SR22 CAPS as a safety enhancement
(for other than spin recovery, and possibly a MAC, structural failure,
loss of control, and landing in inhospitable terrain, *if* they occur
above 920') is inappropriate.

The Nall Report (NR) indicates the phase of flight with the most fatal
pilot-caused accidents (~78% of all fatal accidents) is during what it
calls "maneuvering" (~23%). Since the NR categorizes descent/approach,
landing, go-around, and takeoff/climb distinct from maneuvering, the
maneuvering category would appear to encompass flight regimes presumably at
pattern and cruise altitudes. I would presume then that CAPS would be a
viable option in a large fraction of these cases.

Pattern altitude for light GA aircraft is typically 800' AGL, so it's
not clear that SR22 CAPS would fully deploy from that altitude. Even
at a 1,000' pattern altitude, the aircraft would likely be below 920'
before the PIC realized the necessity for deploying the SR22 CAPS.

What sort of maneuvering above 920' AGL would cause a fatal mishap,
other than a MAC?

Looking at the way the NR categorizes pilot caused fatal accidents, it
seems to me that about half the categories are such that the fatalities
could in theory have been prevented with CAPS.

So you feel that the PIC in those fatal accidents would have had
sufficient altitude to assess the nature of the emergency and decide
to deploy the CAPS with 920' feet to spare?

I'm having a difficult time thinking of what the cause of such
accidents might be. CFIT doesn't fit. I agree, that a MAC might
permit a pilot to deploy a CAPS, unless it was similar to November 16,
2000 C-172 vs F-16 MAC that disintegrated the pilot and his Skyhawk.

So CAPS might have been
potentually life-saving in about 0.78*0.5 = ~40% of all fatal GA accidents.

I'd have to know more about the nature of the criteria you used in
arriving at that conclusion before I'd accept it.

The non-pilot caused accidents allegedly accounted for ~22% of accidents,
but the fraction that happened at altitudes sufficient for effective CAPS
deployment is unknown. Assuming SWAG of ~50% of those 22% happened at
altitudes high enough for CAPS use, then CAPS would be potentially life-
saving in ~11%.

So in theory if all GA craft were equipped with CAPS and pilots were
trained in their effective use, they might cut the number of fatalities in
GA accidents by roughly half.

Only if one accepts your assumptions.