Dear wiggly-amps technofiles
Re EFI for GA:
I would assert that the failure rate of the whole system ie black box,
looms, power source etc is significantly worse than duel mag systems. The
duel mag always wins because it is positively checked at every flight so we
have a dual system with a relatively low MTBF requirement.
Since we can't compete with the dual mag system we need to ask what is the
real reliability requirement. A good benchmark is the probability that the
pilot will spontaneously drop dead at the controls. My friends in the CAA
tell that this is about 1 in 1000000 per flying hour. My anecdotal
experience with cars with black boxes tells me that EFI is not that
reliable, particularly if subjected to a relatively low level of TLC.
Making an EFI duel channel with genuine redundancy is not so easy as it
first appears (as we found at Cosworth). In any case times sequential
injection is completely unnecessary for an aircraft engine which spends most
of its life running pseudo-steady state.
This whole area is under continuing discussion within a working group in the
JAA so clearer (and I believe sensible) guidelines will emerge. We then
need viable technical solutions to emerge!
Regards......MARK WILKSCH
-----Original Message-----
From: ami mcfadyean <ami@mcfadyean.freeserve.co.uk>
<milesm@avnet.co.uk>; europa@avnet.co.uk <europa@avnet.co.uk>
Date: Wednesday, August 25, 1999 06:06
Subject: Re: Flying: Fuel consumption in 'Classic' with Rotax
912.
>OK, OK,so mechanically injected 2-stroke charged diesels are superior to
>everything else!! but the failure rate of modern automotive FI electronics
>compares favourably with the rate at which TWIN magneto failures kill and
>injure people in the US.
>Just to put things in perspective.
>
>However the reliability of the wiring is another matter. I agree that in
>this respect some car based solutions are less than ideal.
>
> Bosch, nevertheless (the manufacturer of the K and subsequent electronic
>systems) consider the latter to be more reliable. Maybe they have an axe to
>grind (and they don`t make the wiring).
>.
>
>Duncan McFadyean
>
>-----Original Message-----
From: Wilksch Airmotive <mark@wilksch.com>
><europa@avnet.co.uk>
>Date: Monday, August 23, 1999 9:49 PM
>Subject: Re: Flying: Fuel consumption in 'Classic' with Rotax
>912.
>
>
>>Dear Miles
>>
>>
>>I have a better way of doing it. Pure machanical with electronic
trimming.
>>
>>There is no use in messing about with car based solutions. The only one
>>which will succeed in the long run is one designed to do the right job for
>>aviation - no
>>compromises. I would love to get one up and running on a 912! My
>>solution will also work on 200,000 Lycontinentals.
>>
>>Development cost is the problem - will Nigel help us with the budget?
How
>>many orders can you get me?
>>
>>I can show you some of the components next time we meet - you will be
>>impressed!
>>
>>Regards...........MARK WILKSCH
>>
>>
>>
>>
>>-----Original Message-----
>From: Miles McCallum <milesm@avnet.co.uk>
>>Date: Monday, August 23, 1999 11:55
>>Subject: Re: Flying: Fuel consumption in 'Classic' with Rotax
>>912.
>>
>>
>>>Carbs.. CV carbs... I don't want carbs at all: I want fuel injection.
>Nigel
>>>has the kit (not Rotax - they won't do it) but he won't get around to it
>>>until enough people show an interest......
>>>
>>>M
>>>
>>>
>>
>>
>>
>
>
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