Engine quit.

Thanks for the suggestions. Thinking back, when I did the run up, checking the mags, when I turned the key, it did seem different. Can’t say why, but did seem different. Everything else was normal, so I didn’t give it another thought. Glad it did restart, but not a good feeling.

I too would suspect the key switch. It shouldn’t quit like that, and cycling the key switch off/on, points to grounding & ungrounding the mags.

I have no clue as to your alternator issue. Is an audible warning device part of your alternator upgrade? My PlanePower alternator upgrade only has a warning light. I guess you could have it wired up to a buzzer.

Diane - glad you're okay!

I agree with Larry in thinking that an alternator problem wouldn't stop the ignition system.

If this were me, I would be suspicious of the ignition switch. There have been quite a few issues over the years with carbon contamination & worn metal particles inside old ignition switches. Eventually there's enough buildup to conduct electricity... the ignition is suddenly grounded as if you turned the key to "off."

In other cases, the contacts inside the switch wear down so much that they're *never* grounding so even though you turn the key to the off position, the magentos remain "hot" and this has killed/injured a few people (when they turned their prop *with the ignition off* and their engine started unexpectedly) leading to ADs being issued for certain ignition switches.

I tend to think it's not a worn p-lead wire grounding to the airframe, unless they both happen at the same time. Anything is possible though.

The fact that it restarted and ran correctly after you "cycled" the key (maybe disrupting some conductive gunk inside, maybe just jostling an accidentally grounded p-lead out of its grounded condition) makes me really suspicious of the ignition switch.

If I had to guess about why the alternator event happened at the same time... a failing alternator can release a brief high-voltage pulse and maybe that caused a static charge that roused a bunch of carbon dust inside the switch? There's my "conspiracy theory" for the day!

Today I flew my Forney for about 1.5 hours.  Everything was fine until near the end.  I was flying along, and with no indication of a problem, the engine stopped.  I was over a field, so tried to locate the problem.  I turned both mags off, and then back on.  Engine immediately started and ran flawlessly for the rest of the flight.  Only other issue was that the alternator out light was on.  On the ground when I went to turn off the plane off, the alternator light was still on and there was a loud warning sound coming from that area.  The sound continued after I turned off the plane and slowly wound down.  Any suggestions?