---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 06/29/09: 22 ---------------------------------------------------------- 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 _____________________________________ Time: 01:58:05 AM PST US From: Andrew Butler Subject: AeroElectric-List: Noise Problem 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 _____________________________________ Time: 03:17:58 AM PST US From: "Gordon Smith" Subject: AeroElectric-List: =?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 _____________________________________ Time: 03:21:07 AM PST US Subject: Re: AeroElectric-List: Complex aircraft NTSB report From: Richard Girard 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 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 > > --> > > > 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 _____________________________________ Time: 04:44:23 AM PST US From: Subject: AeroElectric-List: 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" 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 _____________________________________ Time: 05:17:09 AM PST US From: "Ed Anderson" Subject: RE: AeroElectric-List: 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.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 _____ 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 _____________________________________ Time: 05:18:21 AM PST US Subject: Re: AeroElectric-List: Electric dependent Engine - Pucker Factor? From: Sam Hoskins 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 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 _____________________________________ Time: 08:30:16 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 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 _____________________________________ Time: 08:31:40 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Noise Problem At 03:52 AM 6/29/2009, you wrote: > > >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 _____________________________________ Time: 08:43:35 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: 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 ____________________________________ Time: 08:52:57 AM PST US Subject: Re: AeroElectric-List: Electric dependent Engine - Pucker Factor? From: Dj Merrill 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 starting on page 45 with other references for the package at > 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 ____________________________________ Time: 09:21:21 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 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 > > > >starting on page 45 with other references for the package at > 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 ____________________________________ Time: 09:27:08 AM PST US Subject: =?UTF-8?Q?RE: AeroElectric-List: Electric dependent Engine -?= =?UTF-8?Q? Pucker Factor=3F? From: jon@finleyweb.net =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" =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 ____________________________________ Time: 10:11:52 AM PST US From: Kevin Horton Subject: Re: AeroElectric-List: 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" > 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? > > ________________________________ Message 14 ____________________________________ Time: 11:07:14 AM PST US Subject: Re: AeroElectric-List: Noise Problem From: Ian 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: > > > > > >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 15 ____________________________________ Time: 11:42:58 AM PST US Subject: AeroElectric-List: Battery failure From: "tomcostanza" 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 16 ____________________________________ Time: 01:46:02 PM PST US Subject: RE: AeroElectric-List: Battery failure From: 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 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 ____________________________________ Time: 02:48:47 PM PST US From: "Ed Anderson" Subject: AeroElectric-List: 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 ____________________________________ Time: 04:12:49 PM PST US From: Ken Subject: Re: AeroElectric-List: 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 ____________________________________ Time: 05:13:55 PM PST US From: John Morgensen Subject: Re: AeroElectric-List: 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 ____________________________________ Time: 08:47:26 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Battery failure At 01:39 PM 6/29/2009, you wrote: > > >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 ____________________________________ Time: 09:07:29 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Battery failure AeroElectric-List message posted by: 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 ____________________________________ Time: 09:23:18 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Time to Battery Exhaustion 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. 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 . . . ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.