AlexLev Posted July 9, 2020 Report Posted July 9, 2020 (edited) Looking to service my mags. Do you send them for a 500-hour IRAN? OR Swap them out for an overhauled exchange? Curious if anyone has recommendations for the overhaul exchange option as far as who they use? Edited July 9, 2020 by AlexLev 1 Quote
alextstone Posted July 9, 2020 Report Posted July 9, 2020 Looking to service my mags. Do you send them for a 500-hour IRAN? OR Swap them out for an overhauled exchange? Curious if anyone has recommendations for the overhaul exchange option as far as who they use? I'm looking at the same decision tree...I dug into my logbooks and I discovered that the mags where overhauled at 1392 hrs total airframe time then IRAN'ed twice since then. Based on that, I'm going with new ones and while I'm at it, I'm probably going to install a SureFly "eMag" and new wiring harnessesSent from my Pixel 3 XL using Tapatalk Quote
flyingchump Posted July 9, 2020 Report Posted July 9, 2020 I'm interested in this topic. Next week my left mag is getting replaced with a surefly and my right mag will need overhaul or IRAN or swap. My A&P is going to send my right to texas had have it overhauled I think. I'd love to hear about what others have done. Quote
RLCarter Posted July 9, 2020 Report Posted July 9, 2020 I just did this on the 172 (6 cyl), it was only 150 more to go NEW Mag kits which had everything needed, mags, harness, plugs, gskts and hardware 1 Quote
SantosDumont Posted July 9, 2020 Report Posted July 9, 2020 IRAN. Aero Accessories at VNY. I took the mag over there myself and they showed me the machine for testing they use and all the internal components that needed to be replaced. It was kind of cool. Quote
GeeBee Posted July 9, 2020 Report Posted July 9, 2020 My mags get IRAN'd once at 500 hours then they are gone at 1000 hours replaced with brand new. I just consider cost of maintenance. By doing this, I stopped all mag problems. O/H exchange is a crap shoot, usually craps. There is some belief out there you can O/H or IRAN these things forever which is not true. When Continental bought Bendix mags, they were appalled at the condition of the core inventory and that is why they junked them all and replaced the cores with new. 5 years ago if you bought an O/H exchange Bendix mag, it was a highly likely it was a brand new unit. There needs to be a revision on how we view magnetos. They are not capable of more than a few O/H or IRANS, then they are done. I will bet if you start doing some work with a precision optical comparator one would be truly amazed at what we reinstall back into our airplanes for ignition units. 1 Quote
ArtVandelay Posted July 9, 2020 Report Posted July 9, 2020 Since mine were new and first inspection only has 500 hours total, IRAN. If they have 2000+ hours it might be different. Quote
drapo Posted July 9, 2020 Report Posted July 9, 2020 Don't know if it's an urban legend around the mechanic's world, but word has it that you can overhaul a Bendix magneto for ever while Slicks aren't good candidates for overhaul. Quote
GeeBee Posted July 9, 2020 Report Posted July 9, 2020 29 minutes ago, drapo said: Don't know if it's an urban legend around the mechanic's world, but word has it that you can overhaul a Bendix magneto for ever while Slicks aren't good candidates for overhaul. That is true, but even then I don't keep a Bendix mag more than 1000 hours. 1 Quote
toto Posted July 9, 2020 Report Posted July 9, 2020 3 hours ago, GeeBee said: There is some belief out there you can O/H or IRAN these things forever which is not true. On behalf of all dual-mag owners, I hope this isn’t true Quote
Guest Posted July 9, 2020 Report Posted July 9, 2020 Longevity and reliability of magnetos have a lot to do with who does the work. This is what gets replaced by Aircraft Magneto Service in Montana, and what they look like when they’re finished with them. Clarence Quote
RLCarter Posted July 9, 2020 Report Posted July 9, 2020 2 hours ago, drapo said: Don't know if it's an urban legend around the mechanic's world, but word has it that you can overhaul a Bendix magneto for ever while Slicks aren't good candidates for overhaul. Slick don’t make good candidates due to the cost, a few years back there were some really junk PMA’ed parts that didn’t help Slicks reputation (high failure rates). I just replaced a Slick with over 2000 hrs, it had never been in for ANY type of service, the only thing in the logs was Points & Capacitor at 1200 hrs of service Quote
BKlott Posted July 9, 2020 Report Posted July 9, 2020 I had an IA tell me that the 500 hour deal applies to the Bendix mags. He said the Slicks get replaced when they fail. Quote
jetdriven Posted July 9, 2020 Report Posted July 9, 2020 the 500hr recommended inspection applies to all mags. I dont think there are any AD's on the Bendix or Slick magnetos that have the non-rivet style impulse couplers. Quote
jetdriven Posted July 9, 2020 Report Posted July 9, 2020 23 minutes ago, M20Doc said: Longevity and reliability of magnetos have a lot to do with who does the work. This is what gets replaced by Aircraft Magneto Service in Montana, and what they look like when they’re finished with them. Clarence they replace the impulse coupler spring and fly weights every 500hr? Quote
GeeBee Posted July 9, 2020 Report Posted July 9, 2020 Think about it. How long until the cast housing stretches? You can put all the new "guts" in, but when you are finished, you still have a cast housing that is taking a beating, from the bearing races to the seal seats, to the threads the screws turn into, not to mention the flanges which are bolted down with steel billets. Also for whatever reason, many places check the coils but do not replace the coils. Seen a lot of recently O/H mags come up with a bad coil, because they test good on the bench until you heat stress them then it all goes bad. After 1000 hours, I want a new coils and a new coils are about 400 bucks. Add in the rest of the parts and labor and you might as well buy new. Plus when it goes bad, there is no head scratching and "I'll send it back for a rework", you get a new magneto. IMHO, in a SE airplane, the gods of high tension electricity must all be simultaneously appeased for their wrath of each is mighty. 1 Quote
Austintatious Posted July 10, 2020 Report Posted July 10, 2020 7 hours ago, alextstone said: I'm looking at the same decision tree...I dug into my logbooks and I discovered that the mags where overhauled at 1392 hrs total airframe time then IRAN'ed twice since then. Based on that, I'm going with new ones and while I'm at it, I'm probably going to install a SureFly "eMag" and new wiring harnesses Sent from my Pixel 3 XL using Tapatalk This is my plan... Although since my mags are probably a year or two away from needing it, I am hoping that they will begin to allow both mags to be replaced with the E mags. I really don't understand the logic in keeping 1 old school... I get the reason, that being "tried and true" but the thing is, they are NOT that tried and true. They are a very important device with a mechanical means of failure and a high wear rate. The whole POINT of having 2 is in case 1 fails. Is the FAA that scared that an E-mag might fail that they think 2 of them may fail at the SAME TIME? Crazy Quote
carusoam Posted July 10, 2020 Report Posted July 10, 2020 E-mags in the field are still soooo new. Their actual means of failure haven’t been detailed very well yet... MS has quite a few around the US... we are collecting experience by the day.... It will be interesting to see how well they do with the Heats from very hot to verrrrry cold.... They have the opportunity to really blow away the ancient competition... They also have the opportunity to be very disappointing too.... A failed mag won’t matter if it was electric or standard after it is dead... PP thoughts only, not a mechanic... Best regards, -a- Quote
Ragsf15e Posted July 10, 2020 Report Posted July 10, 2020 37 minutes ago, Austintatious said: This is my plan... Although since my mags are probably a year or two away from needing it, I am hoping that they will begin to allow both mags to be replaced with the E mags. I really don't understand the logic in keeping 1 old school... I get the reason, that being "tried and true" but the thing is, they are NOT that tried and true. They are a very important device with a mechanical means of failure and a high wear rate. The whole POINT of having 2 is in case 1 fails. Is the FAA that scared that an E-mag might fail that they think 2 of them may fail at the SAME TIME? Crazy Neither of the current approved electronic mags supplies its own power or has a backup power source. Too many things can go wrong in your electrical system to count on it. If the emags ever get certified with their own power, then maybe but they’ve been trying for a long time. They sound like BK at this point. 1 Quote
Ragsf15e Posted July 10, 2020 Report Posted July 10, 2020 Personally, I had both mags up for 500 hour service and I overhauled one and got a Surefly on the other. Quote
EricJ Posted July 10, 2020 Report Posted July 10, 2020 5 hours ago, toto said: On behalf of all dual-mag owners, I hope this isn’t true Kelly Aerospace will sell you a new one or overhaul your old one. Quote
toto Posted July 10, 2020 Report Posted July 10, 2020 8 minutes ago, EricJ said: Kelly Aerospace will sell you a new one or overhaul your old one. Interesting, thanks for that. I didn't realize that it was possible to buy new Bendix dual mags today. 1 Quote
MikeOH Posted July 10, 2020 Report Posted July 10, 2020 2 hours ago, Austintatious said: This is my plan... Although since my mags are probably a year or two away from needing it, I am hoping that they will begin to allow both mags to be replaced with the E mags. I really don't understand the logic in keeping 1 old school... I get the reason, that being "tried and true" but the thing is, they are NOT that tried and true. They are a very important device with a mechanical means of failure and a high wear rate. The whole POINT of having 2 is in case 1 fails. Is the FAA that scared that an E-mag might fail that they think 2 of them may fail at the SAME TIME? Crazy As a career EE I'm not so sure it is as 'crazy' as you think. Beyond the dependence upon EXTERNAL electrical power, I have seen enough ESD caused electronic component failures to be VERY nervous with both mags being electronic. Nearby lightning strike comes to mind. Further, beyond easy starts (and, one E-mag will do that) I'm not convinced they provide much, if any, benefit for a stationary engine such as those in our aircraft. I'm happy to keep my tractor mags 2 Quote
Guest Posted July 10, 2020 Report Posted July 10, 2020 10 hours ago, GeeBee said: Think about it. How long until the cast housing stretches? You can put all the new "guts" in, but when you are finished, you still have a cast housing that is taking a beating, from the bearing races to the seal seats, to the threads the screws turn into, not to mention the flanges which are bolted down with steel billets. Also for whatever reason, many places check the coils but do not replace the coils. Seen a lot of recently O/H mags come up with a bad coil, because they test good on the bench until you heat stress them then it all goes bad. After 1000 hours, I want a new coils and a new coils are about 400 bucks. Add in the rest of the parts and labor and you might as well buy new. Plus when it goes bad, there is no head scratching and "I'll send it back for a rework", you get a new magneto. IMHO, in a SE airplane, the gods of high tension electricity must all be simultaneously appeased for their wrath of each is mighty. I’d be far more concerned with the stresses that the rest of the engine is enduring than the magneto case which is only supporting spinning parts not reciprocating parts. From these pages, my guess is that more mags fail to say attached to the engine because of poor installation, than mags that fail internally. Clarence Quote
Guest Posted July 10, 2020 Report Posted July 10, 2020 6 hours ago, toto said: Interesting, thanks for that. I didn't realize that it was possible to buy new Bendix dual mags today. That would be interesting if they do. There are still lots of D3000 magnetos in lots of airframes. Clarence Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.