REFLECTOR:FADEC info
Jim Sower
reflector@tvbf.org
Sat, 20 Dec 2003 23:55:14 -0600
<... sounds like you've been sucking on lemons ...>
Don't know exactly what you mean by that, but I guess it has to do with my gift for
coming on too strong from time to time :o) No offense meant. Please don't take any.
I'm not trying to be pissy. I just want some actual information about this stuff.
Something with which to make an informed decision. Platitudes like ... the FAA says
it's OK so don't worry ... don't work well for me. I look at some of the stuff that
the FAA certifies (like the Tomahawk for example, and magnetos and Marvin Dribbler
carbs) and I have to wonder.
<... I'm not overly impressed with the currently-available implementation ....once
certified the cost of ... revisions is prohibitive ...>
Exactly. So I was looking for some convincing reason to believe that they'd done it
right the first time.
<... a limited market for non-certified engine controls, and that market is pretty
diffuse ...>
Last I heard, there were something on the order of 500-600 single engine spam cans
manufactured a year. Heard that homebuilt first flights run 10-15 times that.
Homebuilts can use auto engines while spam cans cannot, so the potential (key word
here :o) market for automotive technology would appear to be 10 - 15 times that of
certified stuff. The reliability of non-certified installations is growing by leaps
and bounds and I expect it to increase exponentially as their history of success
becomes more widely accepted.
<... cover the development cost ...>
The beauty of non certified technology is that Detroit and Yokohama are doing all the
heavy lifting, and they constitute a HUGE "beta site" for us. All that needs done by
us is the peripherals (fuel system, cooling, etc) so our "development" costs are far
from prohibitive. Maybe I'm weird, but I just don't trust the government (and
particularly the FAA) to look out for my best interests. If they say they are, I
would like to see some credible supporting documentation.
As for the principle of FADEC, I'm acquainted with a guy who wants to put a
programmable, super reliable, duplex electronic fuel control and ignition system on a
Continental. It would cost him about the price of one mag. Trouble is, after
installing all this wonderful stuff (he'll have to significantly upgrade his fuel and
electrical systems) he still has a #$)#&$ 1945 Continental. His idea, like FADEC
appears to be an exercise (at the risk of repeating myself :o) in trying to make a
silk purse out of a sow's ear.
When's the last time FAA or GAMA or any of those guys did right by you and me? ....
Jim S.
KeithHallsten wrote:
> Jim,
> It sounds like you've been sucking on lemons. How 'bout a little Christmas
> spirit?!
>
> The FADEC system had to get through the FAA process of sprinkling with holy
> water, so they had to come up with a system that kept the pilot's grubby
> hands out of the finer points of engine operation, and would be pretty
> reliable, if not as efficient as it has the potential to be. I am still
> pretty interested in the potential of fadec, but I'm not overly impressed
> with the currently-available implementation. Unfortunately, once a system
> gets certified the cost of getting the FAA's blessing on system revisions is
> prohibitive, and you stop amortizing the already-sunk development cost.
> Right now there's a limited market for non-certified engine controls, and
> that market is pretty diffuse - if everyone would buy the same system there
> might be enough of a market to cover the development cost, but that's not
> likely to happen.
> Keith
>
> ----- Original Message -----
> From: "Jim Sower" <canarder@frontiernet.net>
> To: <reflector@tvbf.org>
> Sent: Saturday, December 20, 2003 4:31 PM
> Subject: Re: REFLECTOR:FADEC info
>
> > <... safe to say that (probably) all of the gotcha scenarios have been
> addressed ...>
> > That's comforting. I had hoped that my questions were specific enough to
> warrant
> > specific answers. I think it would be interesting to know, if EGTs were
> driving fuel
> > delivery, how they address failure modes such as gradual deterioration
> (inaccurate
> > output) of the probes and how one might go about distinguishing between a
> > deteriorating EGT probe and a deteriorating something else (like cylinder)
> that has a
> > similar effect on EGT.
> >
> > But then again, my questions were somewhat rhetorical. I am much more
> interested in
> > auto conversions for a variety of reasons not least of which is that I am
> not in a
> > position to spend what FADEC costs. Seems to me that spending all those
> thousands of
> > $ to put a "modern" face on an anachronistic Lyc is an exercise in trying
> to make a
> > silk purse out of a sow's ear.
> >
> > Will it be as reliable and accurate as late model automotive fuel
> controls? ... Jim S.
> >
> > Wayne Lanza wrote:
> >
> > > Hi Jim,
> > > If you haven't been made aware of the Aerosance web site - here ya
> > > go...
> > > I worked closely for a week with the designers of the system while
> > > installing
> > > the Continental FADEC system in Velocity's XL Dash 5 demonstrator
> > > aircraft.
> > > They have designed many failure mode operations into the system, safe to
> > > say that (probably) all of the gotcha scenarios have been addressed.
> > >
> > > Have a Great Holiday,
> > > Wayne Lanza
> > > Composite Design
> > >
> > > goto the Aerosance web page at - http://www.FADEC.com
> > > ________________________________________________________________
> > >
> > > On Thursday, December 18, 2003, at 11:16 PM, Jim Sower wrote:
> > >
> > > > I need some help with some specifics on how FADEC works.
> > > > <... FADEC system meters the fuel-air mixture to ... power ... 100
> > > > degrees Rich of
> > > > peak ... cruise ... 100 degrees Lean of peak ...>
> > > >
> > > > Is it safe to assume that this FADEC feature is driven by EGT sensors?
> > > >
> > > > Is it further safe to assume that FADEC varies fuel delivery from one
> > > > cylinder to
> > > > another according to individual EGTs (which of course are caused by
> > > > uneven air
> > > > delivery through the non symmetric intake runners)?
> > > >
> > > > IIRC, EGT probes tend to fail by degrees, giving increasingly
> > > > erroneous readings for a
> > > > while until they quit altogether. How does FADEC [allege?] to deal
> > > > with partial
> > > > failures of EGT probe? Total failure?
> > > >
> > > > Inquiring minds need to know .... Jim S.
> > >
> > > _______________________________________________
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> > --
> > Jim Sower
> > Crossville, TN; Chapter 5
> > Long-EZ N83RT, Velocity N4095T
> >
> >
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>
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--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T