Sydney Hoeltzli wrote:

I think it is well worth reading, especially for those who
seem to feel the tach and the T/C are superfluous.

I read it. I don't really get anything from it which would apply to the
turn coordinator versus AI discussion of late. The author uses some
terminology rather loosely - referring to pressure instruments and
including in the list (I think?) the DG and AI. It's not clear to me
how or why he lost his vacuum driven gyros from the story as posted. I
also think he might have derived some erroneous conclusions from his
close encounter - for example he referred to engine noise as the 'best
guide to inversion.' Sure, engine noise can be helpful for determining
whether the airplane is in a dive or climb, but it might be doing either
while inverted and the pilot may not know.

(What an amazing coincidence that he appeared to have been hit by an R/C
airplane - in a cloud! Pretty unbelievable.)

Like others in the aforementioned thread, I take attitude information
pretty seriously. I fly two vacuum pumps and two AIs. Both AIs are
air-driven. My system vulnerability is my plumbing, which I accept as a
reasonable risk.

My secondary AI lives on the right side of the panel. Now, admittedly I
fly my airplane a lot, and from both seats, and practice partial panel
fairly regularly. (My idea of fun is plowing around partial panel, OEI,
in a single-receiver VOR intersection hold.) As such, I just don't get
the hubbub about the location of the damn thing. If it's on the right
side of the panel and you need to look to the right to see it, then do
so. If you're sitting in the right seat and need to look to the pilot's
side of the panel for information, then do that. If one's scan is so
weak that one can't handle looking across the panel for attitude
indication, one should practice their partial panel skills more often.
If one is more susceptible to spatial disorientation from looking at a
wider swatch of panel real estate, one needs to fly with an instructor
or safety pilot until they're able to handle it. I regard these things
as basic requirements to fly instruments.

In line with this thinking, my personal feeling is that the location of
the indicator may not be the culprit. The problem more likely is the
ability to modify one's actions to properly react in an emergency such
as vacuum or attitude indicator failure in IMC. (And yes, I will always
call that an emergency, regardless of how comfortable one may be flying
partial panel.) I think people that lose their cool in recoverable
emergencies will tend to break airplanes regardless of how their
instrument panel was laid out.

One other side note. You mentioned that the tach should be located
where it can be part of the primary scan. In the Twin Comanche, almost
all of the ships flying have MAP and RPM on the copilot side of the
panel. That area of the panel simply has to be part of your scan if you
wish to include those instruments. Personally, I think this is a good
thing, because it tends to force the pilot to use the whole panel rather
than fixating on the six-pack.

Best,

Ryan
CFI-ASE-AME, CFI-RH, CP-ASMEL-IA, CP-RH, AGI