Hi  Ron,

   I have flown Certified Fadec's also but currently as what I have seen
by Cont. it is a solution looking for a problem.  I also have many
thousands of hours behind a fadec from primitive MU 2K, more expensive,
Lear 35/36, to most expensive Boeing 747-400 and the more expensive the
fadec the more reliable the system is.

But the real problem is not the technology but the attempt to solve even
non problems. If the only goal was to improve the ignition system I am
all for it. Or the only goal was to improve the fuel system I am all for
it. But to try to eliminate the prop control, change the fuel system,
change the electrical system, change the ignition, and remove almost all
control of a rather simple engine, WELL I am concerned and am expressing
my concerns.  I really like what I have seen of the Prism system plus
there facility is outstanding.  I am not sure that the Unison system is
a real solution.

   I ahd the experience flying the Porsche engine when it supposedly
ready for delivery and this experience illustrated this point.  I was
doing some work for a manufacturer who was interested in the engine for
his aircraft.  We were flying the airplane (182) that had the Porsche
engine installed for development. There were about 8 circuit breakers on
the right side of the panel that were just for the engine controls. We
had asked about problems and reliability, we were reassured that the
system was sound and had no single point failures that could cause an
engine failure. I asked the pilot for  Porsche if one of the CB's popped
would the engine have problems and he said 'no'. I asked if he would
mind if I pulled a CB. He said 'go ahead'  and I pulled one at random.
The engine abruptly quit.  We reset the breaker and I asked if I could
try one of the others he said 'yes' and I pulled another at random and
the engine quit.....

   One of the principals was along in the back seat and was floored as
he loved the Porsche autos and could not believe that this had happened,
but he did not buy any of those engines either.

   Having had many various failures of critical systems in flight test
because we were trying to do too much too quickly, I feel that, this
will not be a major solution without mega bucks being spent.  It might
be if the 'little step' method is used to develop the parts
individually.  Lots of inservice time before integrating the parts.
IMHO.

Jack Webb
L 360, L IV

rbrice@inter-linc.net wrote:

> Hi Jack, Re:  below-FADEC Jack, I have many thousands of hours behind
> commercial FADEC systems, and the last homebuilt I constructed was a
> Rotorway Exec Helicopter with FADEC. All my commercial FADEC time is
> airline (AAL), and of course these systems had redundant electrical
> supplies, and were nearly flawless.  My Rotorway, however, has only
> one electrical system, and deserves watching closely.  I watched it
> like a hawk (past tense, as I class 6'd it in a stupid situation that
> was entirely my fault and not related to FADEC!), and it performed
> flawlessly.  It was, needless to say, a non certified system,
> developed by the Rotorway folks, and really was unique. Rotorway's
> system had dual FADEC's, with the secondary one as backup.  If the
> first system failed, it was required to sit down immediately (somewhat
> easier in a helo than fixed wing, GRIN!)