"Jay Honeck wrote in message I've often wondered how a failed magneto
would manifest itself in flight.

With some engines, you might not notice tht a magneto has failed in flight.
I was flying a C-310Q in cruise and one engine burped momentarily but
continued to run normally. While doing my run-up the next day, I discovered
what caused the burp. Nowadays, I train my charter pilots to check the mags
after landing so that if a mag has failed, maintenance has all night to fix
it.

D.