3393RP
En-Route
- Joined
- Oct 8, 2012
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3393RP
In general, I found the education takes place initially but after a time of falling on deaf ears it stops unless an owner brings it up. That same education continuely takes place on PoA, yet every month the same issues pop up and not only by new posters. So long as the owner is the gate keeper to the aircraft there's not much we can do except not sign off things. And we know how well that works.![]()
You, Dan, and others have been trying to educate PoA members about recommended service intervals and their importance for years. The mechanical failure of an ignored magneto in flight can introduce enough debris into the engine to make it quit running. The seriousness of that possibility is obvious.
This poster had no clue of the maintenance status of his Slick magnetos, and one failed after 700 hours and nine years. Doing the math and thus assuming an annual flying average of 77.78 hours per year indicates he flew the mags for 2½ years past the recommended service intervals of 500 hours.
He had to do some "digging" in the engine logbook to determine their hours, and was "surprised" by the failure. I like to believe aircraft owners do more with their aircraft's manuals than remove them from a desk drawer and give them to their mechanic once a year when the annual inspection is due, but obviously that's not true.
Returning from Maine to FL in my 1977 Cessna R172K XP, the left mag went bad. No prior warnings. All of the run ups checked out fine with the typical 50 to 60 RPM drops during the 15 hrs of flights the prior 6 days before the failure. I had to leave the plane in NC awaiting a new Mag.
So I decided to do some digging when I got back to FL and checked the log books. Discovered both the LH & RH were last replaced in 2012 and had accumulated approx 700 hrs before the failure. No indication in the logs that a 500hr inspection had been done.
Since they were the same age, I bit the bullet and had replaced both. I was very surprised that everything checked out normal with the LH Mag until it failed. I thought there would be a slow progression of increasing RPM drops. One flight it’s fine, next flight it drops over 200 RPMs and engine sounds terrible. Is this normally how these Mags fail?