fire wall
josok a crit :
>
>As i understand from Cliff, the rpm is not reduced but stays at 5000. That is
with the preselect setting at cruise. The rest seems to be a manual job, little
better then full manual, which is a far from ideal situation.
>What i am after is a governor that selects the best rpm and map settings at a
certain power setting from the many available combinations. I would expect from
an intelligent controller to do the difficult stuff, like finding the best
setting out of all combinations of rpm, map and throttle settings, maybe even
based on fuel flow.
>It's like the difference between a wing leveler and a state of the art
>autopilot.
>
>
Hi Josok,
What you're looking for is named Full Authority Digital Engine Controler
(FADEC). We all dream of this Holy Grail of engine controlers, but it is
something really hard to develop.
It should take into account MAP, RPM, Fuel Flow, throttle setting, but
also outer air temperature, engine temps and cowl flap position,
pressure altitude, airspeed, flap configuration, engine curves, prop,
aircraft, etc.
Many many measurement points and curves, many many hours of development.
Some degree of redundancy and electrical backup should be built into it,
as well as manual overrides of different kinds. Add a few hundred bench
and test flight hours and you'll be done.
But...chances are this critter will cost more than the engine when and
if someone were to develop it for small airplanes.
Some manufacturers had a try at it (Continental, Thielert), but they are
still in the development stage, with some weird behaviour in the
"corners" of the flight envelope. Weight, cost and reliability are still
an issue.
To date a suitably qualified and proficient pilot is still the lightest,
cheapest and most reliable FADEC. That is...when he sets his engine by
the book ;-)
FWIW,
Regards,
Gilles Thesee
Grenoble, France
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