Maintenance Planning/Mag Overhaul Question

[d0tnet]

Looking for some feedback on how others would approach the following.

Just hit 505 SMOH, 78 hours since annual in October 2014.

Mag drops are consistent and about 30 hours ago security of mags verified.

I'd expect 1-2 calendar months before hitting 100 hour inspection.

Based on above info, which of the following would you do -

a. Get mags overhauled now as the only service item (~week downtime sending out mags, remote A&P requiring chase plane etc)

b. Wait for the mag overhaul to be done with 100 hour inspection upon hitting 100 hours

c. Get mags and the 100 hour inspection done now

d. Split the two and schedule both for 10 hours from now

Also, any plug and play recommendations for replacement of GEM610 engine monitor? Nothing wrong with it, just want to upgrade to latest technology and have easier data log retrieval.

[MB65E]

Insights G1 is a good solution. G2 is a better silution. G1 is fine if you have another means for fuel flow. The G2 includes FF, but that portion is not plug and play. Run the 100hrs off mags, or pull them when you have some free time or the WX is bad. RLB accessories in Addison IL does great work and quick turn around.

Best,

-Matt

[Guest]

Any of the Insight G series is generally plug and play, additional options will add a bit more time if you opt for them.

Your mags don't need an overhaul, they should have a 500 hour inspection carried out. As the inspection is not mandatory you can schedule it with your next 100 hour inspection.

Clarence

[jetdriven]

I agree with Clarence, run on condition till next scheduled inspection, then do both. 500 hr is not mandatory.

[garytex]

Yes, next scheduled hundred hours is probably fine. However I wouldn't push mags too far. I'm really an "on condition" sort of guy, but my experience is that with mags, hours count. They start wearing out at about 500, and 700 would be way too long for my comfort level

[PTK]

As others have said, it's a 500 hour inspection and not mandatory. You know they're secure and you have consistent mag drops, so you're not totally clueless as to the condition.

You could schedule everything to be done at 100 hr. especially if it's a matter of a couple months.

[M20F]

Pulling the mags is a process and it takes a fair amount of hours so I would suggest when you do them to do both. Moomey didn't make them super easy to get on and off (at least on my F model).

[Guest]

Pulling the mags is a process and it takes a fair amount of hours so I would suggest when you do them to do both. Moomey didn't make them super easy to get on and off (at least on my F model).

Generally speaking in a Mooney the larger the engine installed the easier it is to work on. The four cylinder engines have the least amount of room.

Clarence

[lamont337]

I think I've told this story on MS before, but...

I had a mag failure in flight around 400 hours but the mags were high calendar time - around 15 years. (Plane sat quite a bit before I bought.)

Anyway, inspected 2nd mag since it was of similar vintage and the small metal gear on the inside was so loose and wobbly I doubt it would have lasted another 2 hours before it broke free of the shaft. Long story short, I came very close to a 2-mag failure.

500 hour inspection? Absolutely.

Overhaul? Depends on what you find in the inspection.

Are there other factors? Absolutely.

[jetdriven]

Slick mags are one thing and Bendix are another. We have had a huge amount of coil failures and rotor failures in Slick mags in the past 3 years.

Regarding IRAN and overhaul, it's my understanding the only difference is replacement of the shaft bearings, and of course, cost. Next time your slicks go in for the 500-hr inspection and the repair estimate approaches 800$ a mag (coil and points will do it), look at Continental (Bendix). Their latest ad says they accept competitors mags for cores. And their mags are cheaper as well.

http://www.continentalmotors.aero/uploadedfiles/content/ximages/magneto13_webimage-web.pdf

http://www.continentalmotors.aero/uploadedFiles/xSiteMaintenance/Mega_Menu/Images/Magneto%20Ignition_ad.pdf

[triple8s]

Machinery, cars, trucks and especially aircraft will often drop subtle hints telling you what they want and need. If you listen, you can usually stay ahead of the mechanical issues and keep mechanical issues in the maintenance category and hopefully out of the emergency category. From my limited experience I find that mags usually start dropping those hints when it comes time to start the engine because the magnetos are turrning slow and the mixture is rich and pourly vaporized. To help get started there is an impulse coupling or S.O.S. and IIRC only one mag is firing while engine is turning for start up, so any weakness should show at this time.