"Dave S" wrote in message
nk.net...
Peter Dohm wrote:


Just out of curiosity, what usefull information would this give you that
isn't known from the tach?

I realize that some drive systems allow the prop to freewheel if the
engine
stops; but no control is provided, so the benefit to be derived from the
added knowledge is not obvious...

Peter

If your engine tach is inop because the electrical device that displays
it is FUBAR, then you dont HAVE a tach per se to refer to.

What would it tell you?
One item would be wether or not you need to engage the starter in an
air-restart situation. If the prop is windmilling, then you already have
compression/airflow. Just need to add fuel and spark. Engaging the
starter is not likely to help. If its stopped, then engaging the starter
would be a "really good idea (TM)"

Just one of the quirks of pushers without a bubble canopy.. hard to tell
if you are on fire.. hard to tell if you are streaming anything... and
hard to tell if the prop is turning.

Dave

You've really only served to emphasise the correctness of the point that
Highflyer made in two posts during the hour preceeding your post above.

However, I'll play along for one more inning: Please elaborate on the chain
of events that would result in the loss of both engine power and engine
instruments. Please also justify the presumed deviation from the standard
practice of making the engine essentially self sustaining, and at least some
of the engine instruments self powered as well.

Sorry to play the prig,
Peter