---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 09/14/08: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:21 AM - Re: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs (Joe) 2. 01:59 PM - Re: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs (Vernon Little) 3. 04:00 PM - Re: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs (B Tomm) 4. 04:10 PM - P-Mag and E-Mag safety info from canard-aviators list... (Steve Stearns) 5. 04:12 PM - Part 2 forwarded P-Mag E-Mag Safety info... (Steve Stearns) 6. 04:13 PM - Part 3 P-Mag E-Mag Safety info.... (Steve Stearns) 7. 04:14 PM - Part 4 P-Mag E-Mag Safety info.... (Steve Stearns) 8. 04:21 PM - E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner (Steve Stearns) ________________________________ Message 1 _____________________________________ Time: 11:21:59 AM PST US From: "Joe" Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Vern, That was a good idea to measure the voltage across the switch. By measuring from terminal to terminal, do you mean between the switch terminals and not between the fast-on connectors? Is it possible to measure voltage between the rivet and switch terminal? Just curious. Do you live in a high humidity environment? Whether you do or not, the switches are probably failing because of corrosion. Microswitch makes a military grade sealed switch, the TW Series. It might be expensive but could save you aggravation and failure at critical times. But you have already purchased new switches, maybe next time. Here is another suggestion for next time: buy double-pole switches and connect the two halves in parallel. If one side of the switch fails, the other side will keep you flying. Any heat developed in a double-pole switch will be dissipated over a larger area and thus reduce the temperature rise and slow down the corrosion process. Checking voltage drop across switches could be added to the list of things to do at the annual condition inspection. Many planes could be flying with switches that get warm. The pilot is unaware until there is smoke or until something quits working. Joe ________________________________ Message 2 _____________________________________ Time: 01:59:16 PM PST US From: "Vernon Little" Subject: RE: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Hi Joe. I measured between switch terminals, but wasn't able to measure the voltage between the terminal and rivet. My aircraft is about 10 miles from the west coast, but there are no signs of corrosion anywhere. Not only is it hangared, but I keep a heater/blower in the cockpit at all times when not flying. I've considered the double-pole idea, but the wiring is a bit of a pain, and without understanding the root cause, I'm not sure I'd go to the effort. Although I had no smoke in the cockpit, my panel was warm. Then, I did the finger test on the switches to see what was up. I think the finger test is just as good as a voltage drop test if access is limited. I hope that a lot of you are out there now poking at switches to see if they have the same symptoms! Vern -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Joe Sent: September 14, 2008 11:20 AM Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Vern, That was a good idea to measure the voltage across the switch. By measuring from terminal to terminal, do you mean between the switch terminals and not between the fast-on connectors? Is it possible to measure voltage between the rivet and switch terminal? Just curious. Do you live in a high humidity environment? Whether you do or not, the switches are probably failing because of corrosion. Microswitch makes a military grade sealed switch, the TW Series. It might be expensive but could save you aggravation and failure at critical times. But you have already purchased new switches, maybe next time. Here is another suggestion for next time: buy double-pole switches and connect the two halves in parallel. If one side of the switch fails, the other side will keep you flying. Any heat developed in a double-pole switch will be dissipated over a larger area and thus reduce the temperature rise and slow down the corrosion process. Checking voltage drop across switches could be added to the list of things to do at the annual condition inspection. Many planes could be flying with switches that get warm. The pilot is unaware until there is smoke or until something quits working. Joe ________________________________ Message 3 _____________________________________ Time: 04:00:42 PM PST US From: "B Tomm" Subject: RE: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Vern, My RV is no where close to flying yet but I have already purchased Carling toggle switches too. So I will be watching this thread closely and thank you for posting here. I hope that you positively find the root cause and all can benefit. I'm sure Bob will chime in on this but I'm not sure about the theory of using a double pole switch to "spread" the load. A double pole switch may delay the symptom, but it could still occur eventually and possibly very soon after the first set of contacts fail. I guess it depends on what the actual cause of the failure is. Poor crimps, over current heat damage, corrosion, determination due to contact arcing etc. To truly have a secondary (backup) switch, I would think that it would need to be a separate switch that is not used until the primary one fails and is turned off. My opinions only. Your mileage may vary. I hope this failure is positively identified. Bevan _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Vernon Little Sent: Sunday, September 14, 2008 1:55 PM Subject: RE: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Hi Joe. I measured between switch terminals, but wasn't able to measure the voltage between the terminal and rivet. My aircraft is about 10 miles from the west coast, but there are no signs of corrosion anywhere. Not only is it hangared, but I keep a heater/blower in the cockpit at all times when not flying. I've considered the double-pole idea, but the wiring is a bit of a pain, and without understanding the root cause, I'm not sure I'd go to the effort. Although I had no smoke in the cockpit, my panel was warm. Then, I did the finger test on the switches to see what was up. I think the finger test is just as good as a voltage drop test if access is limited. I hope that a lot of you are out there now poking at switches to see if they have the same symptoms! Vern -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Joe Sent: September 14, 2008 11:20 AM Subject: Re: AeroElectric-List: Toggle Switches with Fast-On TabsToggle Switches with Fast-On TabsToggle Switches with Fast-On Tabs Vern, That was a good idea to measure the voltage across the switch. By measuring from terminal to terminal, do you mean between the switch terminals and not between the fast-on connectors? Is it possible to measure voltage between the rivet and switch terminal? Just curious. Do you live in a high humidity environment? Whether you do or not, the switches are probably failing because of corrosion. Microswitch makes a military grade sealed switch, the TW Series. It might be expensive but could save you aggravation and failure at critical times. But you have already purchased new switches, maybe next time. Here is another suggestion for next time: buy double-pole switches and connect the two halves in parallel. If one side of the switch fails, the other side will keep you flying. Any heat developed in a double-pole switch will be dissipated over a larger area and thus reduce the temperature rise and slow down the corrosion process. Checking voltage drop across switches could be added to the list of things to do at the annual condition inspection. Many planes could be flying with switches that get warm. The pilot is unaware until there is smoke or until something quits working. Joe href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.matro nics.com/Navigator?AeroElectric-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 4 _____________________________________ Time: 04:10:55 PM PST US From: Steve Stearns Subject: AeroElectric-List: P-Mag and E-Mag safety info from canard-aviators list... What follows is some critical safety information published by others with a request to please distribute. From my experiences on the canard-aviators listed I believe Marc Z. to be a particularly credible source. My exposure to the other two authors is too limited to have an informed opinion. Steve Stearns Boulder/Longmont, Colorado CSA,EAA,IAC,AOPA,PE,ARRL,BARC (but ignorant none-the-less) Restoring (since 1/07): N45FC O235 Longeze Cothern/Friling CF1 (~1000 Hrs) Flying (since 9/86): N43732 A65 Taylorcraft BC12D ********** Messages from the Canard-aviators list follow ************ 5. Emagair Emag/Pmag Electronic Ignition warning - Part 1 Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm Sun Sep 14, 2008 5:14 am (PDT) Folks: While I had planned on writing a description and warning of the issues that I had on my trip east in July/August with my electronic ignitions from Emagair (Pmag/Emag), the message that was forwarded to the canard-aviators list by Ric Lee, With a write-up by Gary Cotner describing his crash of his Thorp T-18 due to Emag/Pmag failures has prompted me to accelerate the writing of this warning. So here it is. History (short - a search of the COZY mailing list archives will turn up all my previous posts on this subject): In August of 2004 I purchased a Pmag from Emagair to replace one of my magnetos. During operation over the next months, I had numerous issues with intermittent missing. Brad and Tom at Emagair were extremely good at customer service and replaced my units numerous times whenever I had an issue. Obviously, I was not happy about the problems, but I truly wanted them to succeed - the idea for the units is a great one. By the summer of 2005, after having problems with a unit during my Instrument Instruction, and further problems with replacement units, I threw in the towel, sent the unit back, and got a refund. While replacing the unit with a rebuilt magneto with Ken Miller, we discovered some anomalous wear on the Emagair soft drive gear - Ken was very concerned about this, and I'll get to that issue later. Fast forward to February, 2007. I figured they had had more than enough time (1.5 years) to fix any issues that they had, so I wanted to give Emagair another try. I know that many of you thought that I was insane, and given the rest of this story, you may have very well been correct. But I wanted them to succeed and put Slick/Bendix out of business... At any rate, I got a new generation 3 unit (version 113) and installed it. Within the first month, I had issues with mis-timing, and worked with Emagair to replace the unit. After problems with a second unit, I had been able to run for over a year and 120 hours with no issues whatsoever on the third version 113 unit that I had installed in the spring of 2007. I finally felt like they had the issues licked. After having a magneto failure (reported on list) back in early June of this year (2008), I decided that since I had been having good luck with the Pmag, that I'd get an Emag to go along with it to replace the magneto that had failed. Emagair offered to upgrade my existing Pmag from the version 113 that I had to a version 114 at the same time that they were sending me a new version 114 Emag. Hey - something for nothing - take it, right? I installed both units and flew locally for about 10 hours, taking friends for rides, going places for lunch, etc. No problems at all - engine was running like a top. To Be Continued.... ________________________________ Message 5 _____________________________________ Time: 04:12:16 PM PST US From: Steve Stearns Subject: AeroElectric-List: Part 2 forwarded P-Mag E-Mag Safety info... ************** From Canard Aviators **************** -- Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ Back to top Reply to sender | Reply to group | Reply via web post Messages in this topic (1) 6. Emagair Emag/Pmag Electronic Ignition warning - Part 2 Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm Sun Sep 14, 2008 5:14 am (PDT) Continued from Part 1: In mid July, 2008, I headed east at the crack of dawn for a two week trip that would take me to Provincetown, MA for a week vacation, a few days in NJ with my mother and sisters for my father's footstone dedication, and then to OSHKOSH with my wife for the obvious reasons and to give the COZY and Canard fora. I took off at 5:30 AM, just as the sun was rising, and headed east. After about an hour and a half, near Kingman, AZ, the engine started running a TINY bit differently - a mag check seemed clean - it was running OK on either EI, but the CHT's had gone up about 10-20 degrees and the power was down a bit. I continued the flight for another 4.5 hours with no issues, landing in Clinton, OK for gas, oil and a bathroom break. Upon runup, I found that one EI was NOT working at all, but I was in the middle of nowhere and had places to be. I'll be writing another story about all of the poor decisions I made on this 36.5 hour trip, and won't address them here, but I'll just describe the events because that's what's germane to the warning. I decided to take off on one EI to get to Ohio, where I'd be staying overnight with Bill Kastenholz. I took off on one EI, climbed over the airport to cruising level, and headed off. About 10 minutes after takeoff, the second EI kicked in and the engine continued running as it had for the previous 4.5 hours - CHT's a little elevated (but not dangerous), power a bit down from normal. 5.5 hours later I landed in Ohio. The next morning, after refueling, I took off (again on one EI - the bad one seemed to not work when cold and work when hot) and flew towards MA. On the way I stopped at Westerly, RI to visit Don Ponciroli but we didn't connect and I called Emagair to talk to them about the issues I was having with the 114 units. I then flew to Norwood, MA to visit Jose Velez, and after a couple of hours on to Provincetown, MA. Each time, I took off on one EI, and each time, the second one kicked in after 10 minutes of warming up. It was apparent that there was a problem with timing, but since it didn't run on the ground when cold, I couldn't adjust it. Emagair sent me a replacement unit in P'town and I replaced it. A test runup indicated that it was running fine, along with the other one. On Friday of that week, I flew down to Brookhaven airport on Long-Island with my son and nephew to bring my nephew home after the vacation week. There was no issue on that flight, and no issue on runup. However, about 7 minutes after taking off from Brookhaven, just about over Orient Point, the engine suddenly started running like crap - RPM's dropped off, CHT's shot through the roof on two cylinders, and power decreased substantially. I brought the power back and made a precautionary landing with my son at Easthaven. On the ground, I called Ken Miller (whom I had spoken to for a few minutes on the ground at Brookhaven), described the symptoms, and he gave me a few things to look for. It turned out that one of the EI's had failed catastrophically, with the timing shifting by a huge amount (no wonder the CHT's were through the roof - it was firing on the intake stroke). Retiming it twice did nothing - it wouldn't hold a timing set. The one that had failed was NOT the replacement unit - it was the second unit that had worked OK on the whole flight east. The replacement unit was working OK. I had to completely unplug the power from the unit in order to get it to stop firing, but once I did, the engine ran OK on the one EI (the replacement unit) that was left. My son and I took off from Easthaven on the one EI and flew uneventfully back to Provincetown. I called Emagair to let them know, and they agreed to send another replacement to NJ, where I would be the next day. I sent my wife to NJ via car instead of having her fly with me, and we made arrangements for her to fly commercial to OSH rather than with me in the plane - I would pick her up when I got there in Appleton. To Be Continued... -- Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ Back to top Reply to sender | Reply to group | Reply via web post Messages in this topic (1) ________________________________ Message 6 _____________________________________ Time: 04:13:13 PM PST US From: Steve Stearns Subject: AeroElectric-List: Part 3 P-Mag E-Mag Safety info.... *************** Message forwarded from Canard Aviators list follows ************************ 7. Emagair Emag/Pmag Electronic Ignition warning - Part 3 Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm Sun Sep 14, 2008 5:15 am (PDT) Continued from Part 2: In NJ, I received another replacement unit, went out to Caldwell airport and installed it. Checks of both EI's indicated that they were working. The next day I took off and headed to OSH. About 1.5 hours out, over Pennsylvania, one of the EI's started acting up with the same symptoms as the first bad EI - slightly elevated CHT's, timing off a bit, slightly lower power. I navigated from airport to airport, staying as high as was necessary for glide distance, and made it to OSH in 6.5 hours - about 5 after the EI failure. At OSH, I removed the bad EI and took it, along with the other two failed units, to the Emagair booth at OSH. We disassembled the units and found that all three had had catastrophic mechanical failures inside that caused them to not be able to hold timing to any extent at all. Emagair stated that they had not had any failures other than mine of this type, but agreed that this was a design failure. They attributed the failure to excessive vibration caused in some way by my engine, and this plays back to the wear on the removed EI drive gears that Ken Miller and I had seen two years previously. Emagair believed that there was some strange thing going on in my engine that was causing excessive vibration, which beat up the gears and which caused the catastrophic failure of the sensor magnet holder that I had occur three times. I told them that I just needed to fly 11.5 hours more to get home to Tehachapi, and that the plane would be grounded (which it is) for an engine teardown. They did a temporary repair on two of the EI's, which, along with the one in the plane that was still working, gave me three to use for the 11.5 hour flight(s). When I left OSH a couple of days later, I determined that I would also change my flight characteristics to see if I could lessen the stress on the EI's - I never let the RPM's exceed 2500, either in climb or cruise, and I climbed at 140 mph to ensure excessive cooling to the EI. Since the examination of the failed units had pointed to heat and vibration as being the cause of the failures (mechanical - NOT electrical), I wanted to change the heat and vibration signatures of my flying. I was able to fly from OSH to TSP, with one stop in Tucumcari, NM, without any further failures. The plane is grounded and is coming apart; the EI's have been removed and returned, and I've got my refund. Next, I'll describe the issues, the warning, and my recommendations. To Be Continued: -- Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ Back to top Reply to sender | Reply to group | Reply via web post Messages in this topic (1) ________________________________ Message 7 _____________________________________ Time: 04:14:42 PM PST US From: Steve Stearns Subject: AeroElectric-List: Part 4 P-Mag E-Mag Safety info.... ************ Following message forwarded from Canard Aviators List ******************* 8. Emagair Emag/Pmag Electronic Ignition warning - Part 4 Posted by: "Marc J. Zeitlin" marc_zeitlin@alum.mit.edu zeitlinm Sun Sep 14, 2008 5:16 am (PDT) Continued from Part 3: So what's happening here? As Mr. Cottner and Mr. Read have stated, the Pmag/Emag units lose timing information, firing at arbitrary and sometimes random times. Clearly, this screws up the workings of the engine, sometimes to the point of having no power whatsoever. Mr. Cottner had four failures and lost his airplane because of this failure mode - Mr. Read had to make a precautionary landing, and I had three failures and one precautionary landing. Emagair has issued a SB on both the 113 and 114 units. If you recall, I had timing issues with my 113 units as well. They have instituted a "fix" for the issue, notwithstanding that the 114 mechanical redesign was in part already a "fix" for the problems with the 113 versions. The Emagair units use a small magnet and a hall effect sensor to determine crankshaft position. It's an ingenious solution, because it uses a sensor that can determine crank position within 1 degree, not just when at TDC or within 10 - 30 degrees, as some other EI's do. However, the mounting of the sensor magnet has been flawed from version 113 onward. In version 113, the magnet was epoxied into a metal cup at the end of a shaft. The other end of the shaft had the magneto gear on it and was in intimate contact with the accessory case gears inside the engine, along with the engine oil. This guaranteed that the shaft would get just about as hot as the oil in the accessory case - about 200 F, if not more. Due to the very thin bond line of the epoxy holding the magnet in the cup and the differential CTE's (coefficients of thermal expansion) of the magnet and cup, the thermal stresses in the epoxy can be very large, cracking the epoxy. This would allow the magnet to rotate, thereby losing positional accuracy and timing. After having this failure mode pointed out to them (by me) a year and a half ago, and after having refused my offers to assist them in redesigning the mechanical portion of the units gratis (I am a mechanical engineer with 27 years of experience), Emagair, with an EE but no ME on staff, redesigned the magnet holding portion of the units for the version 114's. They soldered the magnet into a large brass holder, and then glued the holder onto the same shaft that the cup had previously been attached to. They then added two locktited set screws to the holder which applied force to the shaft. There was no flat on the shaft where the set screws touched it. This "fix" was far worse than the disease it was attempting to solve, and is the root cause of the horrible performance of the version 114's under heat and vibration loading. Now that the mass of the brass holder has been made much larger than the mass of the magnet alone, the stresses in the glued bond-line are far higher than previously, and under heat and vibration is guaranteed to fail eventually. The set screws do absolutely nothing, since the CTE of brass is much higher than the CTE of the steel shaft, so as the system gets hot, the set screws don't even touch the shaft. Failure of the glue bond line is sufficient to cause the holder to be able to rotate, with the same mis-timing issues as with a magnet disbond in the version 113 units. Although Emagair has issued an SB, describing a "fix", I do not have ANY confidence in this "fix"'s actually working in the long term. As with Mr. Cotner's warning, I don't believe that the keyway and roll-pin are anything resembling an adequate solution to the magnet mounting problem, which is obviously NOT specific to my engine and/or installation. As more hours are put on these units (I fly 120 hours/year - more than twice the homebuilt average), more will fail, and I have no confidence that this fix will substantially change this situation. Recommendations: My recommendations, based on my opinions and my examination of MANY Emagair unit disassemblies are these: 1) If you are flying with a version 113 or 114 product from Emagair, ground your plane immediately and remove the units. Do NOT fly with them, or with the "fix" described in the SB. It will work for a while, but for how long? 2) If you have a unit that you have purchased but haven't used yet, return it for a refund - do NOT put it on your aircraft and fly it. 3) If you were considering Emagair products for your engine, consider something else - do NOT purchase one and put in on your aircraft. When Emagair have hired a competent mechanical engineering firm to redesign their systems, have FULLY tested the units under O-360 type vibration loads for thousands of hours, and publicly published the results, THEN in may be appropriate to consider these units. Until then, it is not. If Mr. Cotner, Mr. Read, and my experiences with these units put Emagair out of business, and it costs some of you the opportunity to get a refund on your units, I'm sorry for that, but Mr. Cotner was lucky, and relying on luck to keep people alive is not acceptable. Everything that I have written here is either my personal experience, my opinion, or my recommendation based on my opinion. I know that many of you are saying (to yourselves or to others) "I told you so", and you're right - you told me so, but my desire for Emagair to succeed overrode what should have been enough evidence to the contrary. Feel free to write me with "I told you so" messages, if it makes you feel better. I'm happy to address any issues, comments, or questions that anyone may have. Since Emagair never responded to my entreaties to sign an non-disclosure agreement with them, I do not have any responsibility not to explain the inner workings of the units or the problems therein. PLEASE, PLEASE, PLEASE - distribute these messages (and Mr. Cotner's and Mr. Read's) to any and all aviation related mailing lists, fora, and printed newsletters. -- Marc J. Zeitlin mailto:marc_zeitlin@alum.mit.edu http://www.cozybuilders.org/ Copyright (c) 2008 http://www.mdzeitlin.com/Marc/ ________________________________ Message 8 _____________________________________ Time: 04:21:41 PM PST US From: Steve Stearns Subject: AeroElectric-List: E-Mag P-Mag Safety info - Referenced msg from Mr. Cotner ************ Forwarded from Canard Aviators list **************** Fellow fliers, I received this from a friend on the Bearhawk owners group. I have no dog in this fight but feel it is important for everyone to be aware of. Ric Lee Sandy, Utah --------------------------------------------------------------------------------\ -------------------------------------- Received this as a forward to the Bearhawk group. My name is Gary Cotner Until August 11th I had flown my Thorp T-18 N57GC for twenty years and 1500 hours without any problems. That all changed. Story to follow. I will try to keep it very factual and objective. To all the people on the list and any of the people that you might know that fly with E-MAG or P-MAG on their planes. I want every body to forward this to all concerned. I want this to get out to the aviation community at large. I am going to tell what happened to me. I bought two P-MAGS from E-MAG and put them on the plane prior to going to OSH this year. Flew to OSH and had a good time as usual. On the trip home about 45 minutes out the engine started having an intermittent miss. Was going to Kirksville, MO for fuel, decided to divert to Iowa City, IA. Good thing I did I almost didn't make it. Had to dead stick land there. The left P-MAG had failed completely and the right one was intermittent. I called the E-MAG people and they sent me an E-MAG and P-MAG to replace the defective ones. Put them on and ran the tests 6 times and all was well. Full power runs and mag checks went well. Took off and at about 800 agl the engine started running so rough that I wasn't sure it would maintain altitude. From the past experience I needed to get the plane back on the ground before the engine failed completely. Turned back to runway and was way high to land, slipped and still running out of room to land. Had to divert to a closed runway and still short on room got too slow and pancaked in and totaled the plane. This all because of the E-MAG failures. I called these people about the crash and they were very nonchalant about the problem. Said they weren't sure that I in fact had this failure. Invited them to come to my place and I would run the Engine for them. to prove the problem. It has been 8 days since I asked for an answer and no response. I am going to call tomorrow for an answer as to why they haven't answered my call. The plane is still in good enough condition to run the engine. I have since done this and the E-MAG is intermittent and the engine will back fire when the E-MAG is not firing at its proper time. When these units fail they can fire at random and cause the engine to quit. The stress imposed on the crankshaft is very hard and needs to be addressed as an issue like a sudden stoppage. I reference Dave's comments below and highly recommend that you GROUND YOUR plane until you put an other ignition system on it. In other words don't fly it with E-MAGS or P-MAGS on it. I don't want to see anyone die because of these units as they have an inherent design flaw. The fix that they describe is not a good one,roll pins are very brittle and subject shattering. plus drilling a hole in the shaft creates a stress riser and can lead to failure of the shaft. The shaft should not be able to move at all, the sensor should be keyed to the shaft. This item should be removed from the market in it's present design. ===============================================================================\ == All aircraft that are flying with it need to be grounded until they have a different system on them I think those of you who are running E-mag products need to be aware of my experience over the weekend. I am running dual P-mags on my plane. On the return trip from Waco, TX I developed a rough running engine in cruise at altitude. At first it was just an occasional miss or it felt as if the engine was surging slightly. As time went on the engine ran progressively rougher. Carb heat had no effect. Mag check, right is fine, engine nearly dies on the left. Made a precautionary landing at cape girardeau, engine running terribly, died on rollout, won't restart. When I quit shaking we eventually determined that the left mag had shifted its timing by nearly 180 degrees. At the time of the mag check I did not recognize that the engine would have run fine on the right mag only, I guess I didn't leave it in that position long enough. Anyway I sent both mags to E-mag and this is what happened as I understand it. The mag senses the motor position by a magnet soldered to a brass cap or sleeve that is attached to the drive shaft by a set screw. Somehow it loosened up enough that it rotated on the shaft. This has happened to a small number of others, they were drafting a letter about it when I spoke to Brad on Tuesday. The fix is they are drilling the shaft and installing a roll pin so it cannot move. The repair will be done at no charge. At this time they were not yet considering it a mandatory update. As a side note I can't thank Jarod Callis enough for allowing us to take his T-18 so that we could make it the last hour on home. ------------------------------------------------------------------------------------- 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.