"Jay Honeck" wrote:
Question: Does anyone know why the old autopilots were hooked up
to a vacuum instrument? This seems like the height of folly, since
a
vacuum pump failure takes down EVERYTHING, as opposed to
the newer units that work off the electric turn & bank.

Autopilots come in two species: rate-based and attitude-based. Yours
is attitude-based, as are many modern autopilots, especially the high
end ones. Rate-based autopilots like my S-Tec 50 tend to be simpler
and cheaper. The fact that they continue to work after a vacuum
failure is a happy coincidence of the fact that turn coordinators are
electric.
--
Dan
C172RG at BFM