There was an article about this in a recent AviationConsumer
(www.aviationconsumer.com).

Regarding the portable units, the gist is that they're capable enough if
you're in a bind. In fact, even something like a Garmin 196 would probably
get you out of trouble (at $999 though, you won't save any money here).
Depending on the flying you do, they also recommend keeping a spare pump
around (they estimate $300), otherwise if you're away from home you'll
either be going home VFR or paying some unknown shop to replace your pump.

Regarding a 337, it seems to depend heavily on your FSDO. Which company
offers a panel mount option?

blue skies,
mark

"Dan Truesdell" wrote in message
...
I'm part owner of a IFR 172E. Nice equipment, but no vacuum redundancy.
I know I can add a dual-rotor vacuum pump or a manifold-driven
alternate vacuum source, but I'd rather have an electric backup (in case
of engine failure). Electric pumps add weight and good backup electric
AI's are expensive. Does anyone have any experience installing/using
the new solid state gyros? I have an iPaq and handheld GPS, so the
"portable" units would be OK. One of the manufacturers has a panel
mounted unit, but apparently it can't go into a production plane. What
are the chances of getting a 337 for that if it is for backup only? I
can do partial panel, but I'd rather have the most capability that I can
get (within reasonable expense).
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