---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 11/15/08: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:21 AM - Lessons Learned, Lessons Forgotten, Tools for Sharing (James H Nelson) 2. 07:12 AM - Re: Lessons Learned, Lessons Forgotten, Tools for Sharing (Henador Titzoff) 3. 07:54 AM - E-mag CATASTROPHIC FAILURES! (Roger & Jean) 4. 08:34 AM - Re: Lessons Learned, Lessons Forgotten, Tools for Sharing (Robert L. Nuckolls, III) 5. 09:05 AM - Electronic ignition reliability (Ed Holyoke) 6. 09:48 AM - Re: Lessons Learned, Lessons Forgotten, Tools for Sharing (Ed Holyoke) ________________________________ Message 1 _____________________________________ Time: 06:21:49 AM PST US Subject: AeroElectric-List: Lessons Learned, Lessons Forgotten, Tools for Sharing From: James H Nelson Ed, Consider having a E-Mag air "P-Mag" as at least one of the ignition sources. That requires no outside source of power after starting. I have two of them on my Rv. They are great. Jim ____________________________________________________________ Save hundreds on an Unsecured Loan - Click here. http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw2QH0Bxn54hc1Q3cSHOASOOlkzcB7rdFTA0otj784iAHvBCB/ ________________________________ Message 2 _____________________________________ Time: 07:12:59 AM PST US From: Henador Titzoff Subject: Re: AeroElectric-List: Lessons Learned, Lessons Forgotten, Tools for Sharing Jim, How many flight hours do you have on these P-Mags? Thanks. Henador Titzoff ----- Original Message ---- From: James H Nelson Sent: Saturday, November 15, 2008 9:18:18 AM Subject: AeroElectric-List: Lessons Learned, Lessons Forgotten, Tools for Sharing Ed, Consider having a E-Mag air "P-Mag" as at least one of the ignition sources. That requires no outside source of power after starting. I have two of them on my Rv. They are great. Jim ________________________________ Message 3 _____________________________________ Time: 07:54:47 AM PST US From: "Roger & Jean" Subject: AeroElectric-List: E-mag CATASTROPHIC FAILURES! I have heard some stories of several Catastrophic failures with the E-Mag. Is anyone aware of what is happening with fixes? I personally would not buy one of these mags until they have been proven to be reliable. I understand that some of these units have been working great, but the failures worry me. Roger ________________________________ Message 4 _____________________________________ Time: 08:34:54 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Lessons Learned, Lessons Forgotten, Tools for Sharing At 09:39 PM 11/14/2008 -0800, you wrote: > >Bob, > >I didn't build the plane, but I did maintain it for more than 3 years (and >annual condition inspections) without noticing the danger posed by the >proximity of the two. I will never overlook this particular issue again. Ahhh . . . the crystal clarity of experience and hindsight! > The builder used a stainless braided line for the brake which crossed > near the battery cable at 90 degrees. The last time I replaced the > battery, apparently I failed to insure separation and it rubbed through > causing the short. What kind of insulation was used on the battery cable? I ask because Tefzel (22759 and cousins) and welding cable are exceedingly resistant to touch-erosion. It takes some sharp-edged (read high pressure) forces which includes grit-laden contaminants on top of motion eat away at the insulation. You mentioned an overbraid on the brake line, if this was steel and finely pitched wires, then perhaps this was the source of high-pressure contact. >The current was conducted along the brake line to the gear leg mount where >it was also rubbing, another oversight on my part. Steel resistance is much higher than copper so it's axiomatic that the overbraid would warm up like heater wires in your toaster. The resulting heat energy would be conducted into the fluid line that was supposed to be PROTECTED by the braid . . . >The 5606 was all boiled off and filled the cabin with smoke. My nephew >declared emergency and shut off the master and E-busses while holding the >canopy part open, so he could breathe, with one hand and flying with the >other. He found an airport and landed and yes, the brake was not >functional. The voltage was measured after the fact, as you surmised, Bob. >When I got there 90 minutes later, the brake line was still in contact >with the cable. The cable had a total of 3 broken strands and some >localized discoloration. There was about a half a square inch of >insulation missing. It was returned to service with a few layers of heat >shrink over the scar. The relatively low damage level to the copper is striking. When it comes to an jousting match between Sir Copper and Sir Steel using electron- lances it's not an even match. I wouldn't be surprised that the fault current flowing was much less than the levels experienced during engine cranking . . . 100 amps is probably more than enough to produce the conditions cited. >The braided line was limp and I made a replacement in the field out of the >aluminum tubing that Van's supplies. There is now very positive separation >between it and the battery cable, believe me. I have replaced the fluid >with the high temp variant, MIL-PRF-83282. I also replaced the O-rings in >the calipers with Viton for higher temperature capacity. The biggest change to your airplane's configuration is the separation. Of course, upgrading fluid system components is not a bad thing to do . . . but when it comes to draining your battery through the overbraid on a non-metalic fluid line, the contents of the line and accessories would not have changed the outcome. >I just wanted to share this story in the hope that people designing, >installing or maintaining systems take a hard look at the way the battery >cable to the contactor is protected from harm. This is pretty much the >only place in the plane where an insulation failure cannot be mitigated by >turning off a switch or automatically by circuit protection. Thank you so much for doing this. Interestingly enough, this incident would not have been classed as an electrically initiated event. Similarly hazardous conditions could have presented had this been a control cable contacting a fuel line where the fuel line fails first or a control cable rubbing the battery cable where the control cable would fail first. These events grow out of failure to mechanically separate and secure potentially antagonistic pairings. I'm sure we're all pleased that this experience had a relatively benign outcome . . . and we hope your nephew is not having nightmares about it. It had to be an exceedingly tense moment. His willingness and ability to prevail in the face of such discomfort is laudable. >The other issue, as has been mentioned, is that if 2 electronic ignitions >are hooked to 1 battery, bad stuff you hadn't accounted for could take >them both down at once. I don't particularly like magnetos and I think >that, barring a failure in the power provided to them, an electronic >ignition is probably way more reliable. The thought of having an magneto, >which will almost certainly crap out at some point, as a backup to a more >reliable system offends my sensibilities. My next airplane will have 2 EIs >on board, and 2 batteries also. One of them may wind up being little to >save weight, but I don't want all my eggs in one basket. Sure. If the AeroElectric Connection philosophy of system architecture is reduced to its simplest terms, it is "failure tolerance". As the airplane is planned, parts procured, installed, tested, operated and maintained, the builder/owner/pilot needs to be constantly considering ways that the failure of any single component becomes more than a maintenance event. The happy pilot is one who never breaks a sweat in the air no matter how much time he sweats turning wrenches on the ground. Your willingness to share this experience goes directly to these deliberations . . . a thought process that is almost never matched by trying to dissect a systems issue in "Never Again" or "I Learned about Flying from That". Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:05:07 AM PST US From: Ed Holyoke Subject: AeroElectric-List: Electronic ignition reliability Thanks for the tip, Jim. I've been following them for some time. Sounds like they have most of their reliability problems solved, but only time will tell on that one. I'm happy that you and others are doing the beta testing. I hope that they prove, long term, to be the great ignitions that they look as if they should be. I try to keep an open mind. I've got almost 4 years and 350 hrs behind the Lightspeed and a thousand hours on the engine, so equipped. A lot of people I know have more time than that on them. So far, that's my choice. One thing I like about them is that the magnet position is fixed on the flywheel and the unit will always get a timing signal that has a direct relationship to the crankshaft position. I suppose that what it does with that info, re: advance, could go haywire, but I've never heard of one report to that effect in the 15 years they've been out there. Another thing I like is that they have an aggressive advance profile which helps with economy, but I've never had any issues with detonation, even though I lean early and often. Disclosure: I have performed some maintenance on the Lightspeed. At about 800 hrs, I replaced the coils, one of which didn't meet the resistance spec of the manufacturer. I replaced the spark plug wires, to be proactive. The timing, when checked at annual, has always been spot on. I replace the plugs at every annual, even though they don't look like they need it. The original Plasma I ignition (which this one is) had an issue with a power transformer running hot. I opened ours and it looked a little scorched, so I had it replaced by Klaus over at Lightspeed with the current version. I also enlarged the air hole and put a larger avionics fan on it and it runs much cooler now. How many hours do you have on yours, so far? Do you have the latest magnet retention upgrade? I, for one, would be pleased to hear longevity/service difficulty reports as time goes on. More info is better info. Pax, Ed Holyoke James H Nelson wrote: > > Ed, > Consider having a E-Mag air "P-Mag" as at least one of the > ignition sources. That requires no outside source of power after > starting. I have two of them on my Rv. They are great. > > > Jim > ____________________________________________________________ > Save hundreds on an Unsecured Loan - Click here. > http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw2QH0Bxn54hc1Q3cSHOASOOlkzcB7rdFTA0otj784iAHvBCB/ > > > ________________________________ Message 6 _____________________________________ Time: 09:48:16 AM PST US From: Ed Holyoke Subject: Re: AeroElectric-List: Lessons Learned, Lessons Forgotten, Tools for Sharing Embedded responses below: Robert L. Nuckolls, III wrote: > > > At 09:39 PM 11/14/2008 -0800, you wrote: >> >> >> Bob, >> >> I didn't build the plane, but I did maintain it for more than 3 years >> (and annual condition inspections) without noticing the danger posed >> by the proximity of the two. I will never overlook this particular >> issue again. > > > Ahhh . . . the crystal clarity of experience and hindsight! Yup! > >> The builder used a stainless braided line for the brake which >> crossed near the battery cable at 90 degrees. The last time I >> replaced the battery, apparently I failed to insure separation and it >> rubbed through causing the short. > > What kind of insulation was used on the battery > cable? I ask because Tefzel (22759 and cousins) > and welding cable are exceedingly resistant to > touch-erosion. It takes some sharp-edged (read high > pressure) forces which includes grit-laden contaminants > on top of motion eat away at the insulation. It was Tefzel. Those braided lines are _very_ abrasive. > > > You mentioned an overbraid on the brake line, > if this was steel and finely pitched wires, then > perhaps this was the source of high-pressure > contact. Yup. > > >> The current was conducted along the brake line to the gear leg mount >> where it was also rubbing, another oversight on my part. > > Steel resistance is much higher than copper so it's > axiomatic that the overbraid would warm up like heater > wires in your toaster. The resulting heat energy would > be conducted into the fluid line that was supposed > to be PROTECTED by the braid . . . > >> The 5606 was all boiled off and filled the cabin with smoke. My >> nephew declared emergency and shut off the master and E-busses while >> holding the canopy part open, so he could breathe, with one hand and >> flying with the other. He found an airport and landed and yes, the >> brake was not functional. The voltage was measured after the fact, as >> you surmised, Bob. >> When I got there 90 minutes later, the brake line was still in >> contact with the cable. The cable had a total of 3 broken strands and >> some localized discoloration. There was about a half a square inch of >> insulation missing. It was returned to service with a few layers of >> heat shrink over the scar. > > The relatively low damage level to the copper is > striking. When it comes to an jousting match > between Sir Copper and Sir Steel using electron- > lances it's not an even match. I wouldn't be surprised > that the fault current flowing was much less than > the levels experienced during engine cranking . . . > 100 amps is probably more than enough to produce the > conditions cited. > > >> The braided line was limp and I made a replacement in the field out >> of the aluminum tubing that Van's supplies. There is now very >> positive separation between it and the battery cable, believe me. I >> have replaced the fluid with the high temp variant, MIL-PRF-83282. I >> also replaced the O-rings in the calipers with Viton for higher >> temperature capacity. > > The biggest change to your airplane's configuration > is the separation. Of course, upgrading fluid > system components is not a bad thing to do . . . but > when it comes to draining your battery through the > overbraid on a non-metalic fluid line, the contents > of the line and accessories would not have changed > the outcome. You are correct. No brake fluid would have put up with this abuse without smoking. If the line had split open in the cockpit, the fluid could ignite making a horrible situation worse. High flash point fluid might have been better if that had happened. I replaced the brake fluid mostly because of concern for brake overheating and fires as reported on the RV-List. This was a good time to make the change. > >> I just wanted to share this story in the hope that people designing, >> installing or maintaining systems take a hard look at the way the >> battery cable to the contactor is protected from harm. This is pretty >> much the only place in the plane where an insulation failure cannot >> be mitigated by turning off a switch or automatically by circuit >> protection. > > Thank you so much for doing this. Interestingly enough, > this incident would not have been classed as an > electrically initiated event. Similarly hazardous > conditions could have presented had this been a > control cable contacting a fuel line where the > fuel line fails first or a control cable rubbing > the battery cable where the control cable would > fail first. > > These events grow out of failure to mechanically > separate and secure potentially antagonistic pairings. > I'm sure we're all pleased that this experience > had a relatively benign outcome . . . and we hope > your nephew is not having nightmares about it. > It had to be an exceedingly tense moment. His > willingness and ability to prevail in the face > of such discomfort is laudable. I have nothing but the greatest respect for how he handled the emergency. He got it done in exemplary manner. He survived. The airplane survived. I don't know how I would have been able to live with the knowledge that my oversight had caused his death. I'm very glad that to have had the opportunity to correct this situation and share it with others without loss of life so dear. The day after the incident, we drove back up there, where I fabbed the new brake line, bled the brake, and re-installed the battery cable and the recharged battery. When the plane was ready, Mark was sort of reluctant to fly it home. I mentioned that, "I'm not telling you what to do, but if it had been my flight, I would want to complete the mission by bringing the bird back home". He decided to go ahead with it and when I met him back at the hangar later, he thanked me for the nudge. He said that he felt a lot better about himself for having faced his fear. I don't recommend having emergencies as a way of gaining confidence, but having been through a carburetor related engine stoppage myself, and handling it, I can attest to the power of such an experience to educate. >> The other issue, as has been mentioned, is that if 2 electronic >> ignitions are hooked to 1 battery, bad stuff you hadn't accounted for >> could take them both down at once. I don't particularly like magnetos >> and I think that, barring a failure in the power provided to them, an >> electronic ignition is probably way more reliable. The thought of >> having an magneto, which will almost certainly crap out at some >> point, as a backup to a more reliable system offends my >> sensibilities. My next airplane will have 2 EIs on board, and 2 >> batteries also. One of them may wind up being little to save weight, >> but I don't want all my eggs in one basket. > > Sure. If the AeroElectric Connection philosophy > of system architecture is reduced to its simplest > terms, it is "failure tolerance". As the airplane > is planned, parts procured, installed, tested, > operated and maintained, the builder/owner/pilot > needs to be constantly considering ways that the > failure of any single component becomes more than > a maintenance event. The happy pilot is one who > never breaks a sweat in the air no matter how much > time he sweats turning wrenches on the ground. > > Your willingness to share this experience goes > directly to these deliberations . . . a thought > process that is almost never matched by trying to > dissect a systems issue in "Never Again" or > "I Learned about Flying from That". I'm ashamed that I didn't catch this before it became an emergency. It would be easier to keep this to myself, but I feel strongly that it is better to bare this in the hope that I can help save a life. Pax, Ed Holyoke > > 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.