I have an all electric ES with round gages for now. Two years ago
when I was finalizing my panel, the choices were less proven and more
expensive. Kirk was the guy who recommended going with steam gages if I
couldn't afford the Chelton. But two years is a long time!
My two cents......
An electronic HSI is no advance. A moving map replaces an HSI, that's
progress. If you want to know your "horizontal situation", try an MX20
with the holding pattern displayed in magenta! That was a chore,
even with an HSI.
Similar thinking on the attitude indicator would mean that a "flight
simulator" view is a real advance. A line with blue above and brown below
isn't really an improvement in attitude awareness. Reliability aside, the
new "glass" isn't new enough for me unless I can see the terrain.
My JPI EDM 900 is more difficult to interpret than good ol' steam gages for
oil temp etc. I used to be able to glance at my Mooney gages, "all in the
green", and I'm back to looking at the runway. The JPI has red and green
bars, but it's much tougher to interpret quickly. The JPI does allow me to
assign temps and pressures that trigger audible and visible warnings.
The EFIS engine gages should change color, or the electronic "needle"
should change from green to yellow to red, have an audible warning or even a
voice warning. I like the gages in the big iron, the numbers change color
too. Digital readouts are great, but I'm not as concerned if my #5
cylinder is at 367 or 368, I just want to know when I'm approaching or reaching
predefined limits.
I'm watching closely for a system that is a major jump in usability before
I rip out my panel for the "glass" upgrade. I would say that Chelton is
about as close as anything out there, with HITS display, easy to interpret
engine display, audible warnings, and reliability.
Mike Easley
Colorado Springs