Cirrus' "Failing Instruments In Rapid Succession"

While I generally agree with your statements about old instruments,
presumably the instruments in a Cirrus SR22 are not very old.

Mike
MU-2


"Michael" wrote in message
om...
Peter R. wrote
An interview with the pilot suggests that poor avionics maintenance may
have been the cause.

I wonder how many of those "Loss of control in IMC" accidents,
generally attributed to pilot error, are really the result of multiple
failures. Face it, guys - we're flying old obsolete junk. I know
lots of pilots who tell stories of multiple failures on a single
flight. It happens.

However, flying into low IMC immediately after the
aircraft returned from maintenance may have been a bad decision.

In my opinion, it's an absolutely unacceptable decision. Test flights
are day-VFR events. I've had things go wrong on test flights before,
and they didn't always have an obvious connection to the maintenance
being performed. However, since I always landed the plane, I was
always able to do a detailed examination of the intact systems
afterwards - and in the end, it always turned out that the failures
were related to the maintenance, though in non-obvious ways that
generally pointed out previous marginal maintenance and/or very poor
design that clearly did not include a complete analysis of the failure
modes.

But of course he had a parachute. Would he have launched into low IMC
without a parachute immediately following maintenance?

Michael

"Mike Rapoport" wrote
While I generally agree with your statements about old instruments,
presumably the instruments in a Cirrus SR22 are not very old.

There's a difference between a new instrument, and an instrument that
was recently manufactured to an obsolete design. I've spent years
designing instruments (not for aviation - no money there) and learned
something interesting. No design is static - it either evolves or
rots.

When an instrument is first designed, there are inevitable growing
pains in manufacturing. This is expected, and it's fairly typical for
a design engineer to spend a fair amount of time in manufacturing to
bring the production people up to speed. But that's not the end.

In a normal environment, there are continuous changes. Upgrades are
made. Production processes are streamlined. Lower cost vendors are
found, and engineering asessments/changes are made to accomodate the
lower cost parts. Subassemblies are outsourced, and invariably the
outsourcing process turns up problems in the documentation. But even
if you don't plan any changes, they happen anyway. Vendors change
their products subtly, or discontinue them completely, or just go out
of business. Design and production changes are made to accomodate
this.

Eventually the design ages to the point where too many parts are
unavailable, better methods exists, and it's time to redesign from
scratch. That's a normal product life cycle.

In GA, the process is perverted. Any change triggers a paperwork
avalanche, so changes are avoided at all costs. Engineering
involvement with a product post-release is dramatically reduced. Life
cycles are very long. As a result, when an unplanned change occurs,
the product often gets worse. This is a well-documented phenomenon in
aviation engines (when was the last time a large Continental jug made
TBO?) but it's even more true for smaller products.

This was a steam gauge Cirrus. The gauges in it were more than likely
of relatively recent manufacture - and obsolete design.

Michael

"Michael" wrote in message
om...
Peter R. wrote
An interview with the pilot suggests that poor avionics maintenance may
have been the cause.

I wonder how many of those "Loss of control in IMC" accidents,
generally attributed to pilot error, are really the result of multiple
failures. Face it, guys - we're flying old obsolete junk. I know
lots of pilots who tell stories of multiple failures on a single
flight. It happens.


Well, maybe *you* are flying old obsolete junk, but a Cirrus hardly
qualifies. In fact, even the old obsolete junk tends to have fairly new
equipment in it.

I know lots of pilots, too. Some of them have even more experience than what
you claim to have. And they tell a lot of stories. I don't think that
necessarily means that the stories are accurate depictions of events or that
the pilots interpreted those events correctly. Even so, I will allow that
multiple failures in different systems happen and I never said that they
didn't. I have lost the radar, the oil pressure in one engine, and had a
life raft deploy and wrap itself around the tail simultaneously while IMC
and in thunderstorms. What are the odds?

My point is that Occam's razor usually works -- the simplest explanation is
generally the most probable. The most probable explanation here is that the
pilot became disoriented and only thought all his instruments were failing
when none of them or perhaps only one or two of them were actually failing.
That does not mean that I don't think what the pilot says happened is
impossible. It is just a less likely scenario. I think you are the only
pilot I know who claims to have your kind of experience who disagrees with
that.

C J Campbell ) wrote:

snip
My point is that Occam's razor usually works -- the simplest explanation is
generally the most probable. The most probable explanation here is that the
pilot became disoriented and only thought all his instruments were failing
when none of them or perhaps only one or two of them were actually failing.
That does not mean that I don't think what the pilot says happened is
impossible.

Your explanation certainly seems plausible to me.

--
Peter

No, the pilot was IFR rated and on an instrument flight plan. He had over 600
hours in his Cirrus which probably makes him one of the higher-time pilots in
type.

Dave Reinhart


C J Campbell wrote:

"Marco Leon" mleon(at)optonline.net wrote in message
...
Sure the chute worked as advertised. Great.

What irks me is how and why the aircraft experienced all these instrument
failures one right after another.

The man flew into IMC at 400 feet (I believe he was VFR and had no
instrument rating) and probably became disoriented. His instruments did not
fail. He did.

"David Reinhart" wrote in message
...
No, the pilot was IFR rated and on an instrument flight plan. He had over
600
hours in his Cirrus which probably makes him one of the higher-time pilots
in
type.


Hmmm. Even though he was instrument rated and on an IFR flight plan, I still
think it is far more likely that he was disoriented than that 'multiple
instruments on different systems' failed. I am not saying that it is
impossible for everything to go wrong, just that it is far more likely for
just one thing to go wrong. In this case, I would suspect the pilot, though
the instruments will certainly need to be checked out in the investigation.

A lot of IFR pilots get into real trouble with the loss of the vacuum
system, even though we supposedly train them to recognize such errors. There
is a lot of difference between a genuine instrument failure and covering up
the instrument with a sticky. I think more training time in the simulator
would be valuable.

"Marco Leon" mleon(at)optonline.net wrote
What irks me is how and why the aircraft experienced all these instrument
failures one right after another. If any of our Pipers/Cessnas/Beechcrafts
had a propensity to experience near simultaneous failures of supposedly
separate systems there would be an uproar. Fresh off a maintenance visit or
not

Is this the airplane that was flown in low IMC on the first flight
after maintenance? If that's the case, then as far as I'm concerned
we're looking at a case of gross pilot error. Test flights after
maintenance should never be in anything other than good day-VFR.

Michael

On 15 Apr 2004 08:02:58 -0700, (Michael) wrote:

Test flights after
maintenance should never be in anything other than good day-VFR.

Just about every flight I made in my SR20 was after maintenance.
Sometimes I had to have maintenance performed at my local FBO just so
I could fly the plane to the Cirrus service center. If I couldn't make
that flight the plane would be grounded for another 2 to 3 weeks while
I waited for the next available appointment.

ArtP wrote
Test flights after
maintenance should never be in anything other than good day-VFR.

Just about every flight I made in my SR20 was after maintenance.

But you do understand that this is not normal, right? My airplane is
almost 40 years old, it's more comples (2 engines instead of one,
retractable gear instead of fixed) and when my plane got into that
mode (it seemed that for a few weeks things were constantly breaking)
I brought it down for 3 months to do an extensive annual and
fix/replace all the problem items.

Sometimes I had to have maintenance performed at my local FBO just so
I could fly the plane to the Cirrus service center. If I couldn't make
that flight the plane would be grounded for another 2 to 3 weeks while
I waited for the next available appointment.

Then you have a lemon. Fix it or get rid of it.

Michael

Michael ) wrote:

Then you have a lemon. Fix it or get rid of it.

Apparently, you don't recall Art's post history sharing his various SR-20
lemon stories. He's been pretty active in this group about that subject.

Knowing about his history, I took his post to be sarcastic humor.

--
Peter