RobertE Posted July 18, 2018 Report Share Posted July 18, 2018 I say “scary” because this was a reminder to me of all the tiny little imperfections that inevitably afflict our 30, 40 and 50 year old aircraft and, every now and then, can actually have a serious consequence. Today after a short flight my right mag was dead. The problem? The insulation on the p-lead had a tiny nick in it (never noticed by anyone before) and the braided ground wire to that mag just so happened to have come in contact with that 1/32 of an inch section of the p-lead. Result? A grounded mag. Glad we’ve got two discrete mags. Makes me wonder if the Mooney’s with Bendix “dual mags” have that single point of failure or is, perhaps the wiring to each of the halves separate. Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted July 18, 2018 Report Share Posted July 18, 2018 Was that an intermittent problem? If so, that must have been a tough one to figure out. Quote Link to comment Share on other sites More sharing options...
KSMooniac Posted July 18, 2018 Report Share Posted July 18, 2018 The dual mag has two separate P-leads. There is an AD to check mag grounding with the ignition switch to verify they work, too. Sent from my LG-US996 using Tapatalk Quote Link to comment Share on other sites More sharing options...
RobertE Posted July 18, 2018 Author Report Share Posted July 18, 2018 Not an intermittent problem. Pleasantly, the first evidence of a problem was when I was 50 yards from a shop that could quickly diagnose the problem. Quote Link to comment Share on other sites More sharing options...
Guest Posted July 18, 2018 Report Share Posted July 18, 2018 Should have been reactively easy to spot during inspection. Old wire spec is not as good as the current spec. Clarence Quote Link to comment Share on other sites More sharing options...
DualRatedFlyer Posted July 18, 2018 Report Share Posted July 18, 2018 Maxwell caught the same exact thing on my Mooney during the prebuy. Told me "you should probably let us fix that before you fly it accross the country to go home." Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted July 19, 2018 Report Share Posted July 19, 2018 2 hours ago, RobertE said: Not an intermittent problem. Pleasantly, the first evidence of a problem was when I was 50 yards from a shop that could quickly diagnose the problem. huh, I guess I would have thought something like that would be. Quote Link to comment Share on other sites More sharing options...
jetdriven Posted July 19, 2018 Report Share Posted July 19, 2018 I’ve had an alternator field wire do the exact same thing. Quote Link to comment Share on other sites More sharing options...
RobertE Posted July 19, 2018 Author Report Share Posted July 19, 2018 2 hours ago, jaylw314 said: huh, I guess I would have thought something like that would be. You know, you make a really good point. The truth is I wouldn’t know if it was intermittent. So maybe that right mag went off and on for a long, long time. Today it just happened to short out when on the ground during my run up. Quote Link to comment Share on other sites More sharing options...
carusoam Posted July 19, 2018 Report Share Posted July 19, 2018 If you have JPI data, Robert... You can probably review the history of flights to see if you got any strange bumps in the EGTs related to a magneto coming and going.... PP thoughts, -a- 1 Quote Link to comment Share on other sites More sharing options...
RobertE Posted July 19, 2018 Author Report Share Posted July 19, 2018 I’ve got an EI engine analyzer but have never been able to download it to a windows 10 laptop. There is a translation program that should allow this old software to work but I’m too tech-deficient, it seems. 1 Quote Link to comment Share on other sites More sharing options...
Danb Posted July 19, 2018 Report Share Posted July 19, 2018 Robert we should start the TD club for those of us that are somewhat tech deficient. May get more members than the CB club 1 1 Quote Link to comment Share on other sites More sharing options...
ilovecornfields Posted July 19, 2018 Report Share Posted July 19, 2018 9 hours ago, RobertE said: I’ve got an EI engine analyzer but have never been able to download it to a windows 10 laptop. There is a translation program that should allow this old software to work but I’m too tech-deficient, it seems. After almost having to cancel a flight due to the nav update being corrupt (and the laptop at home) I finally gave in and bought the Bad Elf Wombat. It’s pretty slick. You can do the nav updates and send your engine monitor data to Savvy using your phone. 2 Quote Link to comment Share on other sites More sharing options...
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