Dave S asks:

If you get your tach signal from your Engine Controller, and your
engine fails because the electrical system or the engine controller
goes kaput, then it is very likely you will not have a tach signal.
(this was the scenario explicitly discussed in the flyrotary listserv)

OK - I guess then you're SOL using the tach :-).

How does the traditional a/c engine do it... hall effect on the
flywheel? Direct drive tach cable?

My Lyc. has two choices - either a mechanical cable (which I've capped
off), or a tap off the magneto P-lead (that's what I use). I guess if
that one mag died, I'd lose tach signal, too.

I guess I was thinking that the engine died from fuel exhaustion, or
throwing a rod or something. If the electrical thing that supplies the
tach signal croaks, then yeah, that's toast.

Some kicked around the idea of a rear view mirror someplace.. or an
optical tach of sorts..

I keep a small pocket mirror in the map pocket to look at my fuel gauges
in the back seat - I think I could see the prop with it.

--
Marc J. Zeitlin
http://www.cozybuilders.org/
Copyright (c) 2006