Today's Message Index:
----------------------
1. 01:58 AM - Noise Problem (Andrew Butler)
2. 03:17 AM - =?us-ascii?Q?Electric_dependent_Engine_-_Pucker_Factor=3F? (Gordon Smith)
3. 03:21 AM - Re: Complex aircraft NTSB report (Richard Girard)
4. 04:44 AM - Head Set Jacks Location ()
5. 05:17 AM - Re: Electric dependent Engine - Pucker Factor? (Ed Anderson)
6. 05:18 AM - Re: Electric dependent Engine - Pucker Factor? (Sam Hoskins)
7. 08:30 AM - Re: Electric dependent Engine - Pucker Factor? (Robert L. Nuckolls, III)
8. 08:31 AM - Re: Noise Problem (Robert L. Nuckolls, III)
9. 08:43 AM - Re: Lee KR-2 System Architecture (Robert L. Nuckolls, III)
10. 08:52 AM - Re: Electric dependent Engine - Pucker Factor? (Dj Merrill)
11. 09:21 AM - Re: Electric dependent Engine - Pucker Factor? (Robert L. Nuckolls, III)
12. 09:27 AM - =?UTF-8?Q?Re: Electric dependent Engine -?= =?UTF-8?Q? Pucker Factor=3F? (jon@finleyweb.net)
13. 10:11 AM - Re: Electric dependent Engine - Pucker Factor? (Kevin Horton)
14. 11:07 AM - Re: Noise Problem (Ian)
15. 11:42 AM - Battery failure (tomcostanza)
16. 01:46 PM - Re: Battery failure ()
17. 02:48 PM - Time to Battery Exhaustion: Re: Lee KR-2 System Architecture (Ed Anderson)
18. 04:12 PM - Re: Electric dependent Engine - Pucker Factor? (Ken)
19. 05:13 PM - Re: Noise Problem (John Morgensen)
20. 08:47 PM - Re: Battery failure (Robert L. Nuckolls, III)
21. 09:07 PM - Re: Battery failure (Robert L. Nuckolls, III)
22. 09:23 PM - Re: Time to Battery Exhaustion (Robert L. Nuckolls, III)
Message 1
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Hello All,
I hooked up my first headset yesterday. I have multiple audio sources mixed using
an AMX-2A mixer from Vx Aviation feeding into a Flightcom 403 intercom. My
496 GPS told me when I turned off the power, my Traffic Watch that it was online
and my EFIS told me voltage was low. My SL30 radio transmitted too, strength
5 and no noise! What a thrill the radio worked out of the box and all that spaghetti
was actually functional!
One caveat. I could hear the inner workings of my AFS 3500 EFIS. Can anyone help
me with identifying the usual suspects that may assist me in tracking down and
eliminating the source of the noise?
Best regards,
Andrew Butler,
RV7 EI-EEO
Galway, Ireland.
Message 2
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Subject: | =?us-ascii?Q?Electric_dependent_Engine_-_Pucker_Factor=3F? |
I have been following the posts on this list for a year or so and 'Lectric
Bob's writings for maybe 10 years. This has led to my understanding of
failure tolerant design, so that if any part fails (as any part can and
will) you go to plan"B" with out needing to raise a sweat. Not considered
as possible failures in this case are such things as prop bolts, wing
struts, connecting rods and the like.
I am considering the use of an Eggenfellner E6.0 Subaru Auto conversion.
The electrical system architecture will basically be Z-19.
There are electrical system designs that are very failure tolerant even for
electrically dependent engines. And there are more and more of these
electrically dependent engines being used all the time. But usually you
have 2 fuel pumps, 2 electrical paths to the fuel injection/electronic
ignition, etc.
The Egg has 1 ECU (Engine Control Unit) computer. Without it functioning
the fan out front does not rotate. It is a computer whose heart is a
microprocessor.
Is a microprocessor in the same league as a prop bolt for reliability?
This is a single point of failure regardless of how many electrical feed
paths are designed to feed it. What is the reliability of a microprocessor;
does it approach a zero failure rate similar to a prop bolt or an RG
battery?
What is the answer for this? Simply accept it and increase the pucker
factor?
Also, I think that I have seen Bob mention that he might be publishing a
Z-19 modification, specific to the Egg requirements and also some potential
pre-flight checklist recommendations for Z-19 and perhaps other designs,
Has this been done and I have missed it?
Message 3
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Subject: | Re: Complex aircraft NTSB report |
Bob C, et al, I agree that this thread is "preaching to the choir", but
every good choir needs to learn a new tune now and then. Without harping on
the subject we often need new examples to illustrate to a potential victim
why what they are thinking of doing, or actually doing for that matter, is a
bad idea. It's always a delicate matter to tell someone you believe they are
going down a wrong path, having a concrete example is just another tool to
get that across.
Rick
do not archive
On Sun, Jun 28, 2009 at 10:28 AM, Bob Collins <bcollinsrv7a@comcast.net>wrote:
> bcollinsrv7a@comcast.net>
>
> I'm building an RV. I leave my hangar door open (I don't understand why
> people don't want visitors, really.) When expert builders stop by -- as
> they
> often do -- I encourage them to look at the project and holler if they see
> something that doesn't look right or could be improved (although I do joke
> that my hangar rules or "no looking closer than from 1 foot!"(g)).
>
> I've been building since 2001 and, yes, I'm a slow builder, but when I was
> growing up, my family called me the "Scotch tape kid," because I took the
> shortest route to fix any problem -- tape. If the airplane project has
> taught me anything at all, "take your time, do it right, and kick the
> people
> who make fun of how long it's taking out of the hangar" are the most
> important.
>
> I fear we're preaching to the choir here, however. People who read
> AeroElectric Connection or hang out here on the list, already have a
> preference for quality and good workmanship.
>
> Bob Collins
> St. Paul, MN.
> Letters From Flyover Country
> http://rvnewsletter.blogspot.com
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert
> L.
> Nuckolls, III
> Sent: Sunday, June 28, 2009 10:01 AM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Complex aircraft NTSB report
>
> --> <nuckolls.bob@aeroelectric.com>
>
>
> At 09:07 AM 6/28/2009, you wrote:
>
> 6/28/2009
>
> The NTSB Report NYC08FA023 contains the following statement:
>
> "14 CFR Part 21.93 requires that any major changes that are made to an
> airplane require inspection by the FAA prior to further flight."
>
> This statement does not apply to the amateur built experimental airplane
> being reported upon in this accident report. Instead it applies to aircraft
> with changes in type design.
>
> Actions required when changes are made to an amateur built experimental
> aircraft are described in the Operating Limitations for that specific
> aircraft.
>
> Thanks for responding to this Bob. It rang
> some alarm bells when I first read it but
> had not yet taken time to research it.
>
>
Message 4
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Subject: | Head Set Jacks Location |
6/29/2009
Hello Angier, You wrote: "..... behind the pilot/co-pilot seatback ......"
Congratulations. After decades of flying many different types of aircraft
with many different locations for the head set jacks I came to the
conclusion that locating the jacks behind the pilot and copilot seats was
the best solution. I built my airplane that way and it has worked great.
When the pilot's jacks are behind the copilot's seat and the copilot's jacks
are behind the pilot's seat it makes it possible to both see and manipulate
the plugs while seated and strapped into your seat. I have used this benefit
many times.
Also the plugs are not banging into your knees while plugged into the
instrument panel and the wires are not dangling across your lap.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
=====================================
Time: 06:32:17 AM PST US
From: "Angier M. Ames" <N4ZQ@comcast.net>
Subject: AeroElectric-List: Re: Splicing of 2 or 3 conductor shielded cable
I am relocating the comm and mic jacks in my Lancair to a position
behind the pilot/co-pilot seatback and so the comm and mic cables need
to be lengthened. Any suggestions here for what would be the best
method for splicing additional length to these cables and also
maintaining the integrity of the shields?
Thanks
Message 5
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Subject: | Electric dependent Engine - Pucker Factor? |
Hi Gordon,
Been flying with my all-electric rotary for over 10 years I originally
used an aftermarket HALTECH F3 unit (single CPU, but did have a mixture
control) ' it failed after 2 =BD years ' fortunately while doing a
run-up on
the ground. I have since flow with a dual CPU EFI system and while I
firmly believe a microchip (if operated within its intended environment
is
about as safe and reliable as anything can be), I feel more
comfortable,
knowing at the flick of a switch I have a back up. The backup does
reduce
the pucker factor -even thought I=92ve never had to use it.
So probably does not answer your question, but just wanted to share
real-world experience with you.
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
<http://www.andersonee.com> http://www.andersonee.com
<http://www.dmack.net/mazda/index.html>
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
<http://members.cox.net/rogersda/rotary/configs.htm>
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
<http://www.dmack.net/mazda/index.html>
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Gordon
Smith
Sent: Monday, June 29, 2009 5:55 AM
Subject: AeroElectric-List: Electric dependent Engine - Pucker Factor?
I have been following the posts on this list for a year or so and
=91Lectric
Bob=92s writings for maybe 10 years. This has led to my understanding
of
failure tolerant design, so that if any part fails (as any part can and
will) you go to plan=94B=94 with out needing to raise a sweat. Not
considered
as possible failures in this case are such things as prop bolts, wing
struts, connecting rods and the like.
I am considering the use of an Eggenfellner E6.0 Subaru Auto conversion.
The electrical system architecture will basically be Z-19.
There are electrical system designs that are very failure tolerant even
for
electrically dependent engines. And there are more and more of these
electrically dependent engines being used all the time. But usually you
have 2 fuel pumps, 2 electrical paths to the fuel injection/electronic
ignition, etc.
The Egg has 1 ECU (Engine Control Unit) computer. Without it
functioning
the fan out front does not rotate. It is a computer whose heart is a
microprocessor.
Is a microprocessor in the same league as a prop bolt for reliability?
This is a single point of failure regardless of how many electrical feed
paths are designed to feed it. What is the reliability of a
microprocessor;
does it approach a zero failure rate similar to a prop bolt or an RG
battery?
What is the answer for this? Simply accept it and increase the pucker
factor?
Also, I think that I have seen Bob mention that he might be publishing a
Z-19 modification, specific to the Egg requirements and also some
potential
pre-flight checklist recommendations for Z-19 and perhaps other designs,
Has this been done and I have missed it?
__________ Information from ESET NOD32 Antivirus, version of virus
signature
database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
_____
Message 6
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Subject: | Re: Electric dependent Engine - Pucker Factor? |
Gordon. Tracy Crook has his EC3 fuel injection/ignition controller and he
may have a version that will work for you. The EC3 has two independent
controllers mounted on a single board in a single box. Here is the link:
http://www.rotaryaviation.com/eficont.html
Tracy is out of town through the end of July, but his business partner,
Laura, is providing some support while he's gone.
Regards,
Sam Hoskins
On Mon, Jun 29, 2009 at 4:55 AM, Gordon Smith <gordonrsmith921@yahoo.com>wr
ote:
> I have been following the posts on this list for a year or so and
> =91Lectric Bob=92s writings for maybe 10 years. This has led to my
> understanding of failure tolerant design, so that if any part fails (as a
ny
> part can and will) you go to plan=94B=94 with out needing to raise a swea
t. Not
> considered as possible failures in this case are such things as prop bolt
s,
> wing struts, connecting rods and the like.
>
>
> I am considering the use of an Eggenfellner E6.0 Subaru Auto conversion.
> The electrical system architecture will basically be Z-19.
>
>
> There are electrical system designs that are very failure tolerant even f
or
> electrically dependent engines. And there are more and more of these
> electrically dependent engines being used all the time. But usually you
> have 2 fuel pumps, 2 electrical paths to the fuel injection/electronic
> ignition, etc.
>
>
> The Egg has *1 *ECU (Engine Control Unit) computer. Without it
> functioning the fan out front does not rotate. It is a computer whose he
art
> is a microprocessor.
>
> Is a microprocessor in the same league as a prop bolt for reliability?
>
>
> This is a single point of failure regardless of how many electrical feed
> paths are designed to feed it. What is the reliability of a microprocess
or;
> does it approach a zero failure rate similar to a prop bolt or an RG
> battery?
>
>
> What is the answer for this? Simply accept it and increase the pucker
> factor?
>
>
> Also, I think that I have seen Bob mention that he might be publishing a
> Z-19 modification, specific to the Egg requirements and also some potenti
al
> pre-flight checklist recommendations for Z-19 and perhaps other designs,
> Has this been done and I have missed it?
>
>
> *
>
===========
===========
===========
===========
> *
>
>
Message 7
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Subject: | Re: Electric dependent Engine - Pucker Factor? |
At 04:55 AM 6/29/2009, you wrote:
>I have been following the posts on this list for a year or so and
>'Lectric Bob's writings for maybe 10 years. This has led to my
>understanding of failure tolerant design, so that if any part fails
>(as any part can and will) you go to plan"B" with out needing to
>raise a sweat. Not considered as possible failures in this case are
>such things as prop bolts, wing struts, connecting rods and the like.
>
>I am considering the use of an Eggenfellner E6.0 Subaru Auto
>conversion. The electrical system architecture will basically be Z-19.
>
>There are electrical system designs that are very failure tolerant
>even for electrically dependent engines. And there are more and
>more of these electrically dependent engines being used all the
>time. But usually you have 2 fuel pumps, 2 electrical paths to the
>fuel injection/electronic ignition, etc.
>
>The Egg has 1 ECU (Engine Control Unit) computer. Without it
>functioning the fan out front does not rotate. It is a computer
>whose heart is a microprocessor.
>Is a microprocessor in the same league as a prop bolt for reliability?
Probably not . . . but they CAN be pretty good.
How's that for a non-quantified answer? Reliability
is an oft discussed topic here on the List. When
we speak of reliability in the military or TC
aircraft world, the discussion necessarily includes
a study of failure rates for individual components
(taken from a handbook written by folks who
purport to know such things). The last reliability
study I witnessed in my career involved the mathematical
analysis of all the pieces and parts that went
into the fabrication of a super-sonic target
we were building for the Navy . . .
http://www.ordnance.org/aqm37c.htm
We expended perhaps 1000 man-hours compiling
the data and publishing a report. I don't recall
now what the numbers were. I don't put much
credence in such activities. They are
exercises in bureaucratic process that make
bureaucrats happy . . .. and they paid us
for it!
Bottom line is that most such systems, if they
are crafted with legacy products by skilled
workers and screened for defects at time
of manufacture will perform as advertised
with low risk of failure. There's that
non-quantified "low" thing again.
But suppose Eggenfellner spent $100,000 and
produced a detailed reliability study of the
system as installed per his instructions
posted at:
http://www.eggenfellneraircraft.com/electrical.htm
Suppose further that he offered a number
of 1.6 failures per million flight hours.
How would you use that number? If you have
competing suppliers and the other guy says
his gizmo has only 0.8 failures per million
flight hours, would you pay double the cost
to get double the "reliability"?
Further, the past week's discussion on a
Subaru powered RV-10 crash vividly illustrates
that a system with 1 failure per trillion
flight hours isn't worth beans if you don't
craft power sources with similarly impressive
numbers.
>
>What is the answer for this? Simply accept it and increase the pucker factor?
Being a diligent observer of demonstrated service
history is a good place to start. I've been
chastised soundly on this List for suggesting
that my observations of B&C's return products
was not a proper expression of "reliability".
I was able to offer from first hand experience
that with thousands of devices in service, his
return rates were on the order of 1-2 units
per month for repair of user induced damage.
I observed no returns for failure of the
product.
Not being inclined to spend $100,000 on a formal
reliability study, I suggested that those
observations were encouraging . . . especially
since we knew how to produce failure tolerant
systems that did not depend on a functioning
alternator for comfortable termination
of flight.
>
>Also, I think that I have seen Bob mention that he might be
>publishing a Z-19 modification, specific to the Egg requirements and
>also some potential pre-flight checklist recommendations for Z-19
>and perhaps other designs, Has this been done and I have missed it?
Some years ago I had some discussion with
Eggenfellner about a product-specific Z-figure.
I don't remember details of the conversation
now except that the idea was not received with
enough enthusiasm for the project to move
forward.
The Eggenfellner website gives us lip-service
for a resource on technique but includes a
statement, "Avoid being lured into thinking that
you can create your own alternative to the EXPBUS
and save time and money."
I've studied the EXPBUS (and similar products)
and written about them extensively. It's easy
to demonstrate that they DO NOT save money.
You can search aeroelectric.com for those
discussions.
At the same time, Eggenfellner's instructions are
painstakingly crafted and well illustrated. I have no
first hand knowledge as to how many of these
systems are flying nor do I know the history
of field service problems. Queries to the various
Lists have to be your most useful places to
put a dipstick into tribal knowledge. But
be aware that while dark-n-stormy night stories
abound in aviation, few tellers of such stories
understand the simple ideas nor do they always
have access to the facts of reported failures.
While there are things in the Eggenfellner
design I would not embrace, it's his kitchen,
his recipe for success, and his reputation
on the line. If you want to go the Z-19 route,
then let's talk about it here on the list
and tap the grey matter and experience of the
membership.
So what ever stories you uncover, bring them
to the AeroElectric List for the assistance
of many minds who are skilled at sifting
significance out of the noise.
Given the demonstrated service history of
automotive engine controllers (in environments
much more stressful than under your cowl)
I'll suggest that concerns for the hardware
are probably not well founded. These pieces
of hardware perform long and hard for
thousands of hours over the lifetime of
the vehicle. It is more likely that your
unhappy day in the cockpit will arise from
failure to exercise due diligence in the
crafting or maintaining your electrical system . . .
or still more likely from venturing into
a flight situation beyond the abilities
of you or your airplane.
There are plenty of nice ol' Lycomings out
there with a huge history of demonstrated
performance that doesn't seem to discourage
many of our ranks from launching into the blue
behind them.
Bottom line is that the risks are never
zero. We can only do our best to mitigate
those risks to acceptable levels. If you're
really worried about it . . . then don't do it.
A worried pilot with a good system is probably
at greater risk than a skilled and thoughtful
pilot with a mediocre system. Your likelihood
of walking away from an unplanned arrival
with the earth has little to do with reliability
numbers and a lot to do with how you approach
duties as pilot, designer and maintainer of
the airplane. This fact has been demonstrated
countless times throughout the history of aviation.
This is why accident rates for OBAM aircraft
are pretty much in step with accident rates in
TC aircraft. Both sets of pilots run off the same
runways, fly into the same mountains, run the
same batteries to destruction . . . or fail to
tighten the same oil drain plug.
Bob . . .
Message 8
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Subject: | Re: Noise Problem |
At 03:52 AM 6/29/2009, you wrote:
><andrewbutler@ireland.com>
>
>Hello All,
>
>I hooked up my first headset yesterday. I have multiple audio
>sources mixed using an AMX-2A mixer from Vx Aviation feeding into a
>Flightcom 403 intercom. My 496 GPS told me when I turned off the
>power, my Traffic Watch that it was online and my EFIS told me
>voltage was low. My SL30 radio transmitted too, strength 5 and no
>noise! What a thrill the radio worked out of the box and all that
>spaghetti was actually functional!
>
>One caveat. I could hear the inner workings of my AFS 3500 EFIS. Can
>anyone help me with identifying the usual suspects that may assist
>me in tracking down and eliminating the source of the noise?
Do you have a copy of the 'Connection? There's
an extensive chapter on noise mitigation that offers a
good start for your investigation
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 9
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Subject: | RE: Lee KR-2 System Architecture |
At 05:51 PM 6/26/2009, you wrote:
>
>Lectric Bob asked:
>
> Have you done a load analysis on minimum
> energy requirements for sustained flight? Exactly
> how many watt-seconds of energy per flight hour are
> needed to run your engine?
>
>Don't have watt-seconds/flight-hour but there is a spread sheet with amps
>required in various flight modes. Here's a link to my electrical system
>design documentation.
>
>http://kr.flyboybob.com/web_pages/kr2/electrical%20and%20instrument/electrical.htm
>At the bottom of the page there are links to the wiring diagrams.
Okay, I've got you drawing. Let me pray over it
for a few days . . .
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 10
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Subject: | Re: Electric dependent Engine - Pucker Factor? |
On 6/29/2009 11:26 AM, Robert L. Nuckolls, III wrote:
> But suppose Eggenfellner spent $100,000 and
> produced a detailed reliability study of the
> system as installed per his instructions
> posted at:
>
> http://www.eggenfellneraircraft.com/electrical.htm
Just fyi, those are an older set of wiring instructions for the
Eggenfellner package. The latest instructions can be found at
<http://www.eggenfellneraircraft.com/ESeriesInstallationGuide.pdf>
starting on page 45 with other references for the package at
<http://www.eggenfellneraircraft.com/iindex.htm>
> The Eggenfellner website gives us lip-service
> for a resource on technique but includes a
> statement, "Avoid being lured into thinking that
> you can create your own alternative to the EXPBUS
> and save time and money."
Please note that the current wiring instructions are quite different
from the old, and do not include the EXPBUS. Refer to page 51 for a
schematic.
fyi
-Dj
--
Dj Merrill - N1JOV
Sportsman 2+2 Builder #7118 N421DJ
http://deej.net/sportsman/
"Many things that are unexplainable happen during the construction of an
airplane." --Dave Prizio, 30 Aug 2005
Message 11
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Subject: | Re: Electric dependent Engine - Pucker Factor? |
At 10:52 AM 6/29/2009, you wrote:
>
> Just fyi, those are an older set of wiring instructions for the
>Eggenfellner package. The latest instructions can be found at
>
><http://www.eggenfellneraircraft.com/ESeriesInstallationGuide.pdf>
>
>starting on page 45 with other references for the package at
><http://www.eggenfellneraircraft.com/iindex.htm>
Interesting! Thank you. At first blush, it looks
like a lower parts count, 'leaner' architecture.
I'll look it over in more detail later. Appreciate
the heads-up . . .
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 12
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Subject: | Electric dependent Engine -?= =?UTF-8?Q? |
Pucker Factor=3F?
=0AHi Gordon,=0A =0AI don't have any facts or answers for you, only a few a
dditional thoughts. =0A =0AI fly a home-brew Subaru EJ-22 engine. It is co
ntrolled by a Real World Solutions EC2 EFI system (two controllers in a sin
gle box, as previously mentioned). I have crafted an electrical system tha
t is redundant and "protective" and that I am comfortable with. That said;
there are lots of single points of failure (as you have already noted - pr
opellor, engine mount, wing, canopy, crankshaft, camshaft belt, etc... - it
is a long list). In my opinion, the chance of in-flight failure of any of
these items is very, very low. I believe the chance of my dual-controller
ECU failing fits into the same category. I make a living in the electroni
cs/computer world and have lots of faith AND experience with such systems.
I fully understand that there are MANY people that don't trust their elect
ronic Timex watch let alone anything more important/complex. =0A =0AI am o
f the opinion that (any manufacturers) late model stock ECU is not a good o
ption for aircraft use due to extreme complexity (require "faking out" a la
rge number of sensors, operational parameters specific to automobile use, e
tc...). However; I do believe that they are VERY reliable. It is hard (prob
ably impossible) to find actual numbers but some very unscientific research
will show you that automotive ECU's just don't fail without some sort of h
elp (out of spec voltage, impact, etc...). I know - nothing scientific or
measurable in this entire paragraph. So, I think you are correct - it reall
y comes down to personal comfort level. This is not a good thing, IMO, as
it delays "progress" (a whole different thread that always gets heated for
the very reason mentioned here).=0A =0ALast I heard, Egg was supplying his
engines with the SDS EFI system (instead of the Subaru ECU - I believe for
the reasons mentioned above). This system has a VERY good history in aircr
aft and many happy customers. Ross Farnum is active on a number of aircraf
t lists, very knowledgeable, very helpful, and "eating his own dog food" (f
lying behind his own product).=0A =0AHth,=0A =0AJon Finley=0AN413JF - Q2 -
Subaru EJ-22=0A[http://www.finleyweb.net/Q2Subaru.aspx] http://www.finleywe
b.net/Q2Subaru.aspx=0A =0ADO NOT ARCHIVE=0A=0A-----Original Message-----=0A
From: "Gordon Smith" <gordonrsmith921@yahoo.com>=0ASent: Monday, June 29, 2
009 3:55am=0ATo: [mailto:aeroelectric-list@matronics.com] aeroelectric-list
@matronics.com=0ASubject: AeroElectric-List: Electric dependent Engine - Pu
cker Factor?=0A=0A=0A=0AI have been following the posts on this list for a
year or so and =98Lectric Bob=99s writings for maybe 10 years.
This has led to my understanding of failure tolerant design, so that if an
y part fails (as any part can and will) you go to plan=9DB=9D w
ith out needing to raise a sweat. Not considered as possible failures in t
his case are such things as prop bolts, wing struts, connecting rods and th
e like.=0A =0AI am considering the use of an Eggenfellner E6.0 Subaru Auto
conversion. The electrical system architecture will basically be Z-19.=0A
=0AThere are electrical system designs that are very failure tolerant even
for electrically dependent engines. And there are more and more of these e
lectrically dependent engines being used all the time. But usually you hav
e 2 fuel pumps, 2 electrical paths to the fuel injection/electronic ignitio
n, etc.=0A =0AThe Egg has 1 ECU (Engine Control Unit) computer. Without it
functioning the fan out front does not rotate. It is a computer whose hea
rt is a microprocessor.=0AIs a microprocessor in the same league as a prop
bolt for reliability? =0A =0AThis is a single point of failure regardless
of how many electrical feed paths are designed to feed it. What is the rel
iability of a microprocessor; does it approach a zero failure rate similar
to a prop bolt or an RG battery?=0A =0AWhat is the answer for this? Simply
accept it and increase the pucker factor?=0A =0AAlso, I think that I have
seen Bob mention that he might be publishing a Z-19 modification, specific
to the Egg requirements and also some potential pre-flight checklist recomm
endations for Z-19 and perhaps other designs, Has this been done and I hav
e missed it?=0A
Message 13
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Subject: | Re: Electric dependent Engine - Pucker Factor? |
If the microchip is operating in suitable physical (temperature,
vibration, moisture, etc) and electrical environments, and it comes
from a microchip manufacturer with a proven track record, then it
should be extremely reliable.
My bigger concern would be software. Is the software simple, with
predictable response to all possible combinations of inputs, or is it
complex? Complex software often fails in unexpected ways, as FADEC
manufacturers for engines on large transport category aircraft keep
discovering (by failure I mean the software produces an unacceptable
output). Sometimes sensors fail in ways that has not been predicted.
What is the response to single and multiple sensor failures?
Kevin Horton
On 29 Jun 2009, at 12:24, jon@finleyweb.net wrote:
> Hi Gordon,
>
> I don't have any facts or answers for you, only a few additional
> thoughts.
>
> I fly a home-brew Subaru EJ-22 engine. It is controlled by a Real
> World Solutions EC2 EFI system (two controllers in a single box, as
> previously mentioned). I have crafted an electrical system that is
> redundant and "protective" and that I am comfortable with. That
> said; there are lots of single points of failure (as you have
> already noted - propellor, engine mount, wing, canopy, crankshaft,
> camshaft belt, etc... - it is a long list). In my opinion, the
> chance of in-flight failure of any of these items is very, very
> low. I believe the chance of my dual-controller ECU failing fits
> into the same category. I make a living in the electronics/computer
> world and have lots of faith AND experience with such systems. I
> fully understand that there are MANY people that don't trust their
> electronic Timex watch let alone anything more important/complex.
>
> I am of the opinion that (any manufacturers) late model stock ECU is
> not a good option for aircraft use due to extreme complexity
> (require "faking out" a large number of sensors, operational
> parameters specific to automobile use, etc...). However; I do
> believe that they are VERY reliable. It is hard (probably
> impossible) to find actual numbers but some very unscientific
> research will show you that automotive ECU's just don't fail without
> some sort of help (out of spec voltage, impact, etc...). I know -
> nothing scientific or measurable in this entire paragraph. So, I
> think you are correct - it really comes down to personal comfort
> level. This is not a good thing, IMO, as it delays "progress" (a
> whole different thread that always gets heated for the very reason
> mentioned here).
>
> Last I heard, Egg was supplying his engines with the SDS EFI system
> (instead of the Subaru ECU - I believe for the reasons mentioned
> above). This system has a VERY good history in aircraft and many
> happy customers. Ross Farnum is active on a number of aircraft
> lists, very knowledgeable, very helpful, and "eating his own dog
> food" (flying behind his own product).
>
> Hth,
>
> Jon Finley
> N413JF - Q2 - Subaru EJ-22
> http://www.finleyweb.net/Q2Subaru.aspx
>
> DO NOT ARCHIVE
>
> -----Original Message-----
> From: "Gordon Smith" <gordonrsmith921@yahoo.com>
> Sent: Monday, June 29, 2009 3:55am
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Electric dependent Engine - Pucker Factor?
>
> I have been following the posts on this list for a year or so and
> Lectric Bobs writings for maybe 10 years. This has led to my
> understanding of failure tolerant design, so that if any part fails
> (as any part can and will) you go to planB with out needing to
> raise a sweat. Not considered as possible failures in this case are
> such things as prop bolts, wing struts, connecting rods and the like.
>
> I am considering the use of an Eggenfellner E6.0 Subaru Auto
> conversion. The electrical system architecture will basically be
> Z-19.
>
> There are electrical system designs that are very failure tolerant
> even for electrically dependent engines. And there are more and
> more of these electrically dependent engines being used all the
> time. But usually you have 2 fuel pumps, 2 electrical paths to the
> fuel injection/electronic ignition, etc.
>
> The Egg has 1 ECU (Engine Control Unit) computer. Without it
> functioning the fan out front does not rotate. It is a computer
> whose heart is a microprocessor.
> Is a microprocessor in the same league as a prop bolt for reliability?
>
> This is a single point of failure regardless of how many electrical
> feed paths are designed to feed it. What is the reliability of a
> microprocessor; does it approach a zero failure rate similar to a
> prop bolt or an RG battery?
>
> What is the answer for this? Simply accept it and increase the
> pucker factor?
>
> Also, I think that I have seen Bob mention that he might be
> publishing a Z-19 modification, specific to the Egg requirements and
> also some potential pre-flight checklist recommendations for Z-19
> and perhaps other designs, Has this been done and I have missed it?
>
>
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Subject: | Re: Noise Problem |
Dr. Bob,
I also have a noise problem. I do indeed have a copy of the
"Connection" and have what you might have described as a "Really off the
wall problem". I wonder if you or any of your "listeners" would have a
clue.
My RV-9A has a Garmin GNX300 XL GPS/Com, a Narco AT165 transponder, a
Dynon EFIS D10A, and a Rocky Mountain enging micromonitor. The comms
are routed through a Flightcomm 403. The power distribution is through
an EXP2BUS.
In flight I get an irregular clankety-clank noise in both headsets that
sounds like someone whacking a rudder cable against the fuselage but
it's electrical. When I remove the headset and listen to the cabin
noise, all I hear is a louder engine noise.
It's all about the same pitch, but almost sounds almost like some form
of sparking or discharging.
There is no whining or other noise, and this seems to only happen when
the engine in running (i.e. most of the time). The sound reduces when I
turn down the volume, and goes away when I "isolate" the pilot from the
passenger on the Flightcomm 403 with the "ICS/Isolate" switch.
This is such a unique noise I just wondered if anyone else had heard it
or heard of it.
Thanks in advance for any of your wisdom.
Ian Brown,
Bromont
Quebec
Mon, 2009-06-29 at 10:29 -0500, Robert L. Nuckolls, III wrote:
>
> At 03:52 AM 6/29/2009, you wrote:
> ><andrewbutler@ireland.com>
> >
> >Hello All,
> >
> >I hooked up my first headset yesterday. I have multiple audio
> >sources mixed using an AMX-2A mixer from Vx Aviation feeding into a
> >Flightcom 403 intercom. My 496 GPS told me when I turned off the
> >power, my Traffic Watch that it was online and my EFIS told me
> >voltage was low. My SL30 radio transmitted too, strength 5 and no
> >noise! What a thrill the radio worked out of the box and all that
> >spaghetti was actually functional!
> >
> >One caveat. I could hear the inner workings of my AFS 3500 EFIS. Can
> >anyone help me with identifying the usual suspects that may assist
> >me in tracking down and eliminating the source of the noise?
>
> Do you have a copy of the 'Connection? There's
> an extensive chapter on noise mitigation that offers a
> good start for your investigation
>
>
> Bob . . .
>
> ---------------------------------------
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ---------------------------------------
>
>
>
>
>
>
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I have read a lot on this forum about alternator failures and e-busses and backup
alternators. Is it possible that the battery can fail in a way that short
circuits the bus, causing a total power failure? If so, is there sufficient probably
that I should design around that?
My RV will be equipped for light IFR, and I'll have an e-bus with sufficient reserve
to fly for an hour after an alternator failure. I may add a 2nd alternator
at some point, but for now, just a single battery/alternator.
--------
Clear Skies,
Tom Costanza
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=250646#250646
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Tom,
What I have read on this list is that yes, batteries fail, but
historically dead shorts are rare and worries are few. Thus, large ANL
protection (200 amp) between battery and contactor are deemed
unnecessary. I have discussed this same topic recently with my
mechanics. They have indicated heat is a real danger of Mr. Battery.
Extreme amounts of it can and will cause dead shorts internally (I've
yet to experience one). Thus, if I am to keep Mr. Battery on the
firewall I am ill advised to protect it with shielding, venting and ANL
fuse to keep it from going poof.
Urban legend? I don't know. Bob will tell us. I do know that while I
have a second alternator, I will add a second battery (in the rear) just
to ensure my plasma III pair keeps on ticking. My design goal? No IFR
landings on rainy nights in the PA woods. Legend also has it that if you
keep the tail really low while landing in the trees on an IFR night, it
won't hurt as bad.
Glenn
Do not archive
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
tomcostanza
Sent: Monday, June 29, 2009 2:39 PM
Subject: AeroElectric-List: Battery failure
<Tom@CostanzaAndAssociates.com>
I have read a lot on this forum about alternator failures and e-busses
and backup alternators. Is it possible that the battery can fail in a
way that short circuits the bus, causing a total power failure? If so,
is there sufficient probably that I should design around that?
My RV will be equipped for light IFR, and I'll have an e-bus with
sufficient reserve to fly for an hour after an alternator failure. I
may add a 2nd alternator at some point, but for now, just a single
battery/alternator.
--------
Clear Skies,
Tom Costanza
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=250646#250646
Message 17
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Subject: | Time to Battery Exhaustion: RE: Lee KR-2 System Architecture |
Having had some recent real-world experience with battery exhaustion, I
though some of you might be interested in actual flight duration with all
systems on - until the battery voltage dropped below that necessary to run
crucial flight systems.
Without going into the "why it happened - switch in wrong place, deficient
design" as that has already been posted to this forum, rather this is the
following systems I had on during the period of battery-only powered flight:
1. Engine started from battery (naturally) after refueling - no recharging
after start - due to switch in wrong position.
2. Two 50 watt Landing lights ON (my normal practice for take off and
landing)
3. Two High pressure EFI fuel pumps (probably drawing 4-5 amps each)
4. One 6 psi boost pump
5. 4 electronic fuel injectors
6. 2 ignition modules
7. 1 radio
8. 1 transponder
9. 1 Gps
10. 1 Strobe light on
I took off with a 1 1/2 year old PC 680 Odyssey battery (which as I
mentioned above did not get alternator recharge after engine start - so was
somewhat depleted).
I took off and flew for 45 minutes before (dropping battery voltage) started
to manifest itself in undesirable and very noticeable ways. Approx 50
minutes after take off I found the engine would no longer run - prop
stopped. Approx 54 minutes after take off while in engine-out glide to Craig
Field, Selma, Al. The master relay (held closed by battery voltage) gave up
and removed the alternator and therefore all power from the system. Dead
panel, dead engine - rather lonely. Did get one radio call off before panel
went dead.
No - low battery voltage will not show up if your voltmeter and low voltage
warning LED happens to be on the alternator circuit and the battery is
disconnected from the alternator - which is one of the reasons I had problem
convincing myself it was anything other than a fuel problem - but, it was
solely electrical, inadvertently (you don't think I did it on purpose do
you?) induced by the pilot and supported by a design deficiency - no
isolation diode between battery and alternator only a switch(which ended up
in the wrong position).
Next morning, once switch was placed in the proper position (connecting
battery to alternator) a test flight was made and all checked out and I
continued on to Texas. Flew back with no incident. However, I doubt the
battery would do as well a second time as the voltage had dropped to 6 volts
by the time I checked on the ground. From what I understand is that once a
battery undergoes that degree of discharge, its capacity is less than it
was.
The battery is rated at 17 AH, don't know how much the engine start drained
but at 400 amp for say 5 second for engine start = 0.55 amp-hour leaving
theoretically 16.45 amp hour in the battery. Flew for 45 minutes before the
dropping voltage started undesirable things happening so 45/60 = .75 hour of
battery powered flight. That theoretically would indicate a 16.45/.75 = 21
amp/hour load. Clearly lots of estimation here but that load (with two 50
watt landing lights on) does not seem unreasonable to me. YMMV
But all things considered - the battery did a credible job of lasting as
long as it did. Just wanted to post a real world example of battery power
duration.
Lessons learned - stick in the isolation diode so battery will get
alternator juice regardless of essential bus switch
position
- Put check of Essential bus switch on emergency as well
as regular check list
- Don't fixate on what you "THINK" the problem is, check
both fuel and electrical
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
Message 18
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Subject: | Re: Electric dependent Engine - Pucker Factor? |
As reliable as ecu's are, solid state electronics and wiring often don't
give much warning before failing. So I opted for Z-14 with a second
independent engine control system running off the second electrical
system. At 300 hours I too have never needed it. It is handy for
troubleshooting as well as pucker minimization.
In the past, a manual backup valve to feed fuel into the intake manifold
was mentioned. Another thought would be a switch (and diodes) to
ground all the injectors low side. On an installation with separate
backup ignition, positive voltage supply to the injectors, and positive
fuel pump control, that will keep the engine running as long as the
throttle is kept at near a cruise setting or higher, even after a total
EFI system electronic failure. Certainly simpler, if less elegant in
operation, than my second ecu system. A robust exhaust system would be
in order and of course the challenge of implementing it without reducing
primary system reliability.
Ken
Gordon Smith wrote:
> I have been following the posts on this list for a year or so and
> Lectric Bobs writings for maybe 10 years. This has led to my
> understanding of failure tolerant design, so that if any part fails (as
> any part can and will) you go to planB with out needing to raise a
> sweat. Not considered as possible failures in this case are such things
> as prop bolts, wing struts, connecting rods and the like.
>
Message 19
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Subject: | Re: Noise Problem |
I have a noise in the Flightcomm 403 intercom that I would describe as a
snare drum. It goes away when the squelch is adjusted.
John
Ian wrote:
>
> Dr. Bob,
> I also have a noise problem. I do indeed have a copy of the
> "Connection" and have what you might have described as a "Really off the
> wall problem". I wonder if you or any of your "listeners" would have a
> clue.
>
> My RV-9A has a Garmin GNX300 XL GPS/Com, a Narco AT165 transponder, a
> Dynon EFIS D10A, and a Rocky Mountain enging micromonitor. The comms
> are routed through a Flightcomm 403. The power distribution is through
> an EXP2BUS.
>
> In flight I get an irregular clankety-clank noise in both headsets that
> sounds like someone whacking a rudder cable against the fuselage but
> it's electrical. When I remove the headset and listen to the cabin
> noise, all I hear is a louder engine noise.
>
Message 20
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Subject: | Re: Battery failure |
At 01:39 PM 6/29/2009, you wrote:
><Tom@CostanzaAndAssociates.com>
>
>I have read a lot on this forum about alternator failures and
>e-busses and backup alternators. Is it possible that the battery
>can fail in a way that short circuits the bus, causing a total power failure?
No. We used to see the occasional shorted
cell in flooded batteries. This could cause
a 12 volt battery to become a 10 volt battery.
Remaining good cells then suffered overcharging.
RG batteries don't do this.
> If so, is there sufficient probably that I should design around that?
No
>My RV will be equipped for light IFR, and I'll have an e-bus with
>sufficient reserve to fly for an hour after an alternator
>failure. I may add a 2nd alternator at some point, but for now,
>just a single battery/alternator.
Start out with Z-11 which is easily morphed
to Z-13/8 at a later time.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 21
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AeroElectric-List message posted by: <longg@pjm.com>
What I have read on this list is that yes, batteries fail, but
historically dead shorts are rare and worries are few. Thus, large ANL
protection (200 amp) between battery and contactor are deemed
unnecessary.
Correct. If current limiters are found in battery
circuits, they are to protect WIRES from the fault
currents that can flow (1000+ amps) when a battery
becomes the SOURCE driving a HARD FAULT.
I have discussed this same topic recently with my
mechanics. They have indicated heat is a real danger of Mr. Battery.
Extreme amounts of it can and will cause dead shorts internally (I've
yet to experience one). Thus, if I am to keep Mr. Battery on the
firewall I am ill advised to protect it with shielding, venting and ANL
fuse to keep it from going poof.
RG batteries contain a relatively small amount
of moisture compared to the flooded
cells of yesteryear. When an RG battery is
deliberately abused by either hard fault or
overcharge, the manufacturer is well advised
to design cases to withstand over-pressures
(typically 2 PSI) whereupon the vent valves
open and the battery goes "sssssss" not
"boom".
I used to have running conversations with
the Navy's battery test facilities in Crane
Indiana where EVERY battery in Navy inventory
and many other batteries were test for worst
case outcomes in horrible failure modes.
Our friends at Concorde were routinely subject
to Crane's House of Battery Horrors to verify
their suitability to task in military programs.
It's an easy and not terribly expensive
thing to try for yourself. Hook 3 golf cart
6v batteries in series and hook 17 a.h.
RG in parallel with it. Thermocouple the
battery, watch the current as the 18v
source "cooks" the 12v battery. Test #2 calls
for throwing a dead short across the same
fully charged battery and tracking temperatures
and currents.
Early on in the history of all batteries,
there were some spectacular outcomes for
these tests. However, given the ubiquitous
presence of the SVLA battery in everything
from video cameras to toys to airplanes to
submarines, the family of suppliers have
pretty much all become righteous citizens.
When you see fuses in series with batteries,
it's to protect external things from the energy
the batteries contain . . . not vice versa.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 22
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Subject: | Re: Time to Battery Exhaustion |
<eanderson@carolina.rr.com>
Having had some recent real-world experience with battery exhaustion, I
though some of you might be interested in actual flight duration with all
systems on - until the battery voltage dropped below that necessary to run
crucial flight systems.
<snip>
Next morning, once switch was placed in the proper position (connecting
battery to alternator) a test flight was made and all checked out and I
continued on to Texas. Flew back with no incident. However, I doubt the
battery would do as well a second time as the voltage had dropped to 6 volts
by the time I checked on the ground. From what I understand is that once a
battery undergoes that degree of discharge, its capacity is less than it
was.
This is why the Z-figures and other writings in
the 'Connection suggest ACTIVE NOTIFICATION OF
LOW VOLTAGE on the main bus. When you turn the
battery master on before cranking the engine, that
light is an irritating feature on the panel and
remains so until the alternator comes on to boost
the bus above 13.0 volts.
The battery is rated at 17 AH, don't know how much the engine start drained
but at 400 amp for say 5 second for engine start = 0.55 amp-hour leaving
theoretically 16.45 amp hour in the battery. Flew for 45 minutes before the
dropping voltage started undesirable things happening so 45/60 = .75 hour of
battery powered flight. That theoretically would indicate a 16.45/.75 = 21
amp/hour load. Clearly lots of estimation here but that load (with two 50
watt landing lights on) does not seem unreasonable to me.
See . . .
http://www.aeroelectric.com/Pictures/Curves/17AH_12V_Capacity_vs_Load.gif
The typical 17 a.h. battery being discharged in 40
minutes when presented with a 17A load. This yields
a useful capacity on the order of 17 x 0.7 or 12 ampere
hours.
But all things considered - the battery did a credible job of lasting as
long as it did. Just wanted to post a real world example of battery power
duration.
Lessons learned - stick in the isolation diode so battery will get
alternator juice regardless of essential bus switch
position.
Without seeing your power distribution diagram, I'm
not sure what the "isolation diode" is about. Active
and irritating notification of low voltage becomes
a expected event that cannot missed or ignored. I
requires no training and/or checklist activity for
making sure things are up and running before flight.
Bob . . .
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