Another SR22

Recently, Thomas Borchert posted:

Larry,

But if the aircraft is below 1,000', the CAPS system is probably not
an option.


IF you are in a fully developed spin (1 full turn, as certification
requires and the handbook says), traditional spin recovery isn't an
option either at 1000 feet.

Why not? Are you implying that 1 full turn spin loses too much altitude,
and if so, based on what? Some planes spin pretty flat, while others are
pretty nose-down, which type is the SR22?

Neil

Neil,

Why not?


Because you won't make a recovery from a fully developed spin in less
than 920 feet with a plane of the approximate weight and size of the
Cirrus, say a Bo. Remember, you have done one complete turn in a fully
developed spin. Then you start counting when you apply rudder in the
opposite direction and push the yoke (or whatever conventional recovery
is to you). From that point to a positive climb rate, there's no way
you'll lose less than 920 feet of altitude. And certification doesn't
even require you to.

--
Thomas Borchert (EDDH)

On Fri, 27 Oct 2006 17:18:30 +0200, Thomas Borchert
wrote in
:

Larry,

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

How do you arrive at that conclusion?

The way I read the quote from the SR22 POH, it requires 920' to fully
deploy the CAPS. Do you have information to the contrary?

My point is, that CAPS is not an option at the times it's needed most:
below 920'.

That's not what your own quote says. It says it is not an option if you
arrive at less than 920 feet after one full turn in a spin.

So you feel that less altitude would be required for full CAPS
deployment if the aircraft hadn't archived "one full turn in a spin?"
You'll have to cite some objective information that supports that
notion before I'll change my opinion from what is written in the SR22
POH.

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.

Well, the people saved by it in different circumstances would probably
beg to differ.

Are you able to provide any credible information about the
circumstances to which you refer?

"Jim Logajan" wrote in message
.. .
Terry wrote:
What's with the SR22 crashes? Another one went down Arizona yesterday.

It's the seatbelts. Aircraft manufacturers add those worthless devices to
cars and planes, yet people keep dying in car and plane crashes. Seatbelts
clearly add a false sense of security and are therefore responsible for
the
accidents.

(The above is not meant to be taken seriously.)

Yeah they just take up useful load if you ask me!

------------------------------------------
DW

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.

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

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.

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.

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.

Maybe. But it costs weight and money. This means that, for the same
flight, the plane carries less gas, and this is the leading cause of
crashes. One could fly with more fuel stops, this increases the number
of landings and takeoffs (and low altitude flight). Since there's less
money, the airplane might be less well equipped, and the pilot might be
less well trained. This increases the risk too.

Everything comes from somewhere.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

Stefan writes:

At least, I tend to believe so, after having lost
three friends in midairs (two events).

Losing them without a parachute doesn't mean that a parachute would
have saved them.

--
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Kingfish writes:

You're half right here. It's true ABS won't shorten stopping distances,
unless you can singlehandedly alter physics. What it does do is allow
you to maintain steering control while in a panic stop by not locking
up the wheels

But very often the obstacle to be avoided is directly ahead of the
car. And any attempt to turn the vehicle in a panic stop greatly
increases safe braking distance (because wheels that turn are much
more likely to skid or lock).

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Peter Duniho writes:

So while ABS doesn't change the *theoretical* minimum stopping distance, it
does change the practical minimum stopping distance for most drivers.

Unfortunately, most drivers don't know the minimum stopping distance
to begin with, and dramatically underestimate it, or simply choose to
ignore the correct distance for convenience. ABS often will not help
them, unless they get lucky.

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