Marc J. Zeitlin wrote:


Everybody's got a tach, right? Is that not sufficient?


Believe it or not, NO...

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)

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

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

Dave