500 Hour Mag Check

[thomas1142]

What is it, what does it consist of? My J is due it’s 500 Mag check, it is at annual right now. Mechanic wants to send away for rebuild due to 500 hr check. Both mags check just fine during run up, 80 on Left, 100 on Right. Does anything need to be done?

Thanks

Angelos

[jetdriven]

Forget rebuild. But a 500hr insp with new capacitors by aero accessories van Nuys Is solid gold 

[EricJ]

A common issue is replacing the large drive gears, which are plastic and get brittle with use from exposure to the ozone generated inside the magneto.   If those aren't replaced the brittleness often leads to lost teeth, which slips the timing or produces intermittent or otherwise undesirable behavior. 

Checking the caps and points and resetting the internal timing also helps stay ahead of issues as well.

The 500 hour inspections are good insurance.   It used to be that many shops had the parts and equipment do them in-house, but these days they usually get sent out to somebody.

[Fly Boomer]

47 minutes ago, thomas1142 said:

What is it, what does it consist of? My J is due it’s 500 Mag check, it is at annual right now. Mechanic wants to send away for rebuild due to 500 hr check. Both mags check just fine during run up, 80 on Left, 100 on Right. Does anything need to be done?

Thanks

Angelos

Mike Busch suggests shopping for a shop that will do an IRAN.

https://www.aopa.org/news-and-media/all-news/2021/february/pilot/savvy-maintenance-mags

[MikeOH]

Not a good idea to skimp on this maintenance item.

Another positive vote for Aero Accessories in Van Nuys, CA

[toto]

We're presumably talking about a Bendix dual mag, right?

The number of shops that will IRAN a dual mag is somewhat limited.  I had mine done at Kelly last year and it was pretty expensive, but the mag has been running well.

[Utah20Gflyer]

If it were me and the plane has been flying regularly and everything seems to be in good working order I would get an IRAN done.   When performing an IRAN they should replace everything that is substandard.  This may be much less than an overhaul or could be much more.   They could even end up telling you the mag isn’t repairable.   The only difference between the two choices is with the Overhaul they will replace certain parts whether they need to or not.  Either way all the parts that aren’t up to snuff will have to be replaced.  

[EricJ]

10 minutes ago, toto said:

We're presumably talking about a Bendix dual mag, right?

The number of shops that will IRAN a dual mag is somewhat limited.  I had mine done at Kelly last year and it was pretty expensive, but the mag has been running well.

Same here, Kelly did mine and it's been good.  

[Niko182]

+1 for aero accessories as well. Shipped in, repaired, and I picked it up the following day.

[N201MKTurbo]

Can anybody show where it is required? There is an AD mandated inspection of some impulse couplings. 
 

Not saying it isn’t a good idea, but everybody seems to think it is a requirement. 

[Niko182]

Just now, N201MKTurbo said:

Can anybody show where it is required? There is an AD mandated inspection of some impulse couplings. 
 

Not saying it isn’t a good idea, but everybody seems to think it is a requirement. 

I don’t believe it’s a requirement. I thought I’d was an SB.

[toto]

7 minutes ago, N201MKTurbo said:

Can anybody show where it is required? There is an AD mandated inspection of some impulse couplings. 
 

Not saying it isn’t a good idea, but everybody seems to think it is a requirement. 

Definitely not required, but definitely a good idea. 

[jetdriven]

I like the guys  in Montana the best, but they don't work on the dual mag so I send those to Aero accessories.

[MooneyMitch]

11 hours ago, jetdriven said:

Forget rebuild. But a 500hr insp with new capacitors by aero accessories van Nuys Is solid gold 

Interesting…… a few years ago, I had a mag failure with approximately 75 hours since Aero Accessories 500 hour service.  The mag was returned to them and the report was a failed condenser.  The shop told me replacement of the condenser is not part of the 500 hour service if condensers tests ok.

Possibly Aero has now made cap replacement part of the service. Or does one have to request the cap replacement as part of the 500 hour service? There was no charge to replace the failed capacitor.  Excellent service from them.  

[jetdriven]

We also had a capacitor fail and we had to send a mag back for another check so since then I will specify new capacitors on everything that gets sent out

[Marc_B]

It's interesting that Mike Busch is an "on condition" and limited maintenance type guy, yet he firmly recommends a 500hr inspection.  Especially for the turbo drivers with pressurized mags.  Whether Slick or Bendix, a 500 hr IRAN seems like good insurance to avoid issues and keep from being AOG somewhere difficult. 

I've got Slick 6324 pressurized mags, and the right mag started having issues prior to 500 hrs.  So I replaced it with a SureFly and the ignition is running much better than before.  FYI, my ground mag check was fine but my in flight mag check performed LOP was super rough on the right...meaning, a ground mag check isn't the best stress test for your ignition and doesn't catch every issue.

https://www.aircraftmagnetoservice.net/500-hour-inspection-details

@thomas1142 There are a lot of wear parts such as brushes, contacts, etc that get replaced during an IRAN.  Check out the link above.  This is one of the shops that a lot of people recommend.  If you go to their home page it also shows their current turn time.

[RoundTwo]

I just got back airborne after being AOG for 4 days due to the left half of the mag crapping out. It wasn’t cheap, but being stranded is worse. Luckily we were only 100 miles from home so the Uber trip wasn’t horrible. 
 

Do the inspection, period. 

[JimB]

And just another suggestion, for those that do not have an all-in-one dual magneto. If you have 2 separate mags, split them up. Have one inspected one year and one inspected the next year. Just don't have the same mechanic remove them install them and the same shop inspect and repair them at the same time... people make mistakes, that's just being human. But you have redundancy in 2 separate ignition systems, you might as well take advantage of it. 

[EricJ]

2 minutes ago, JimB said:

And just another suggestion, for those that do not have an all-in-one dual magneto. If you have 2 separate mags, split them up. Have one inspected one year and one inspected the next year. Just don't have the same mechanic remove them install them and the same shop inspect and repair them at the same time... people make mistakes, that's just being human. But you have redundancy in 2 separate ignition systems, you might as well take advantage of it. 

I always thought a good plan with separate mags would be to have impulse couplers on both and then have a third mag ready to go.   On a staggered schedule when one comes up for maintenance just swap in the third one and minimize down time.   

[PT20J]

4 hours ago, EricJ said:

I always thought a good plan with separate mags would be to have impulse couplers on both and then have a third mag ready to go.   On a staggered schedule when one comes up for maintenance just swap in the third one and minimize down time.   

And, I guess the spare mag should be kept in the baggage compartment for road trips.

[DXB]

4 hours ago, EricJ said:

I always thought a good plan with separate mags would be to have impulse couplers on both and then have a third mag ready to go.   On a staggered schedule when one comes up for maintenance just swap in the third one and minimize down time.   

That's a pretty good idea.   And now with so many folks going with a left Surefly that's good for 2000 hours, just having a spare right mag ready to go may be all that is needed.

[GeeBee]

Having a different mechanic install them, is not a new idea. It is the basis of ETOPS maintenance. The same mechanic cannot work on or service both engines. 

As for having a third mag, I have a spare I keep on the shelf, just in case. It has bailed me out more than once. The core charge is cheap enough to keep one.

 

[N201MKTurbo]

3 hours ago, M20Doc said:

I tried to order my engine with some Lycoming parts, some Continental parts and some Superior Airparts parts in order to spread my risk and improve reliability.  I also wanted a few used parts to minimize infant mortality.  No builders would play ball.

 

Wow, my engine has some Lycoming parts, some Continental parts and some Superior parts.

[JimB]

 

13 hours ago, M20Doc said:

I tried to order my engine with some Lycoming parts, some Continental parts and some Superior Airparts parts in order to spread my risk and improve reliability.  I also wanted a few used parts to minimize infant mortality.  No builders would play ball.

 

10 hours ago, M20Doc said:

Or just pick a competent maintainer, and be willing to pay them to read the books when needed.

11 minutes ago, M20Doc said:

Yes but without some used parts it’s more likely to fail. Next thing you’ll tell us that the guy who assembled it also installed it and flies it.  A very dangerous situation.

Damn Clarence, do I sense a bit of sarcasm here?  

[N201MKTurbo]

1 hour ago, M20Doc said:

Yes but without some used parts it’s more likely to fail. Next thing you’ll tell us that the guy who assembled it also installed it and flies it.  A very dangerous situation.

All true. Much more dangerous than when the engine was in pieces.