Grounded By Maintenance Issue

I got up at 4:30 this morning for a 6am flight. I get to the airport, do my weight/balance/performance calculations and preflight the aircraft. I get the can and look at the squawk box and notice that it was squawked yesterday for a significant drop in RPM with the left magneto after 3 leaning attempts. Maintenance closed out the squawk noting only a minor drop in RPM. Note to self, pay extra attention at run-up.

We get in the plane, do all the preflight briefs and taxi. While taxiing, I notice that the tach is varying about 100RPM. During runup, the left magneto shows a 450RPM drop! I think that might be classified as SIGNIFICANT. I try three times to clear it with zero effect. Back to the ramp.

Of course there are not any other planes available, so the day is shot. Maintenance should have replace the magneto yesterday or taken the a/c out of service. Now I trust them even less.

Recommendation to new pilots: Always be cautious of maintenance issues. Don't just check the tach times against the maintenance sheet. Make sure that every necessary system on the aircraft is working perfectly. It's never worth the risk to take someone else's word for it, no matter how experienced they are. Things get overlooked. Overworked A&P's may get sloppy. Problems can be intermittent.

The reason I'm saying this is that in between yesterday's and today's write-up for the same issue, a private student flew the aircraft on a solo. I doubt the magneto was better. Did he do a runup check? I doubt it. Did he have enough experience in the aircraft to realize that it still didn't sound right even with both magnetos on? Probably not.

There are enough ways to die in a small aircraft. Why add to the list?