"Bill Denton" wrote in message ...
I have noticed that American Champion offers three different panel "types"
on the Super Decathlon:

No gyro instruments.

Vacuum gyro instruments.

Electric gyro instruments.
....
So how do electric gyro instruments fit into the equation? Are they less
susceptible to damage from aerobatics than vacuum gyro instruments? Are
there any other advantages?

I can't answer the aerobatic Q or if there are other advntages, but do
know of a major disadvantage, at least within the experience detailed
below. They are highly failure prone and very expensive, both to buy
and fix.

I have a motor glider with no vacuum pump on the engine and the time
I'm most likely to need a gyro is if the engine won't start and I have
to descend through a cloud layer. So an electric gyro was really the
only option. I put an RC Allen Artificial Horizon in the plane, had it
fail after a few years and not work all that well during those years,
had it overhauled for $1k, and had it fail again soon afterward. When
I did an avionics upgrade, I pulled it out and now rely on my Garmin
196 (which has a gyro like page) for the small probability that many
things go wrong and I need a gyro. I'm also really careful not to get
into those situations, but fate can conspire against the best of
plans, so I wanted some backup option.

My experience with the RC Allen electric AH is not unusual, in fact
it's the norm within the fleet I'm a part of -- at least within the
part that has a gyro. (Most owners don't bother with any gyros since
we're limited to VFR flight.)

I also had heard similar stories of frequent failure from a flight
school that had a fleet of the older Katanas with the Rotax 912 engine
(similar to my 914) which also had no vacuum pump and RC Allen
electric AH's.

That said, the little checking I've done has indicated that most, if
not all, "reasonably priced" (under $3k!) electric AH's are relatively
unreliable, so it may not be just RC Allen. An electric turn and bank
gyro may be a different story since they are in more widespread use
and much cheaper.

There are some new solid state "gyros" out that you may want to look
at. Sounds like a much better approach in general and for aerobatics
particularly.

Hope this is of some help.

Martin