I think a ground rule
for any emergency analysis is that we do not assume multiple independent failures.
However; I currently do not have a backup tach – rpm comes from the EC2,
and EC2 failure takes the tach with it. But then we do have a backup
controller. One question that I have - Is it assured that in an engine
out (due to ignition, fuel, etc.) that the prop will windmill at glide speed?
Probably different for different planes, so it may be something that has to be
determined. I’m guessing that using a reduction drive makes it more
likely that it will not windmill.
Oil pressure and voltage level would tell
you whether the engine was spinning.
My initial thought about knowing whether
the prop is turning or not had to do with knowing whether the engine had ‘frozen’;
although I would expect that it is very unlikely to occur without some advance
notice.
It does seem that a mirror; or perhaps a
miniature video camera somewhere, giving a view of the engine end of the plane
would be a useful item.
But while you tractor guys are thinking.
“Yeah, well what sense does it make o have the engine in back anyway”;
I’ll add that even just taxiing my plane, with the smoothness of the
rotary, and without that prop spinning up front, was a bit like a magic carpet
ride.
Al
In a
message dated 5/13/2006 7:44:25 AM Central Standard Time, rijakits@cwpanama.net writes:
Tachs
also can go bad/out.
I find
the idea with the rearview mirror on the winglet excellent!
Of
course you dont stick an actual mirror there, but put some stainless foil with
adhesive backing on. You don't need a telescope clear image, just enough to
tell wether the club is milling or not....
Try it
out, if it doesn't work, all it takes is little WD40 to remove the glue...