I thought that gyro bearings were very susceptible to damage if subjected to
mechanical shock while not turning. If that is true, then turning it off in
flight may actually reduce the service life.

wrote:

In our plane, this installation also allowed plenty of space to install an
ON/OFF switch next to the electric AI. We leave it off when flying in solid
VFR conditions, with the understanding that this will extend its life. So
far, so good. It's required no maintenance in over 7 yrs/1400 hrs (knock on
wood).

-Elliott Drucker

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759