500 hrs mag inspection - mandatory or reccmendation

Norman said:
On a 2,000 hour engine? Tell me a Mother Goose.
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Nearly the same thread is happening on the Socata.org website. The guy has a plane with 1500 hours on new Slick Mags. No issues. They are running fine. He is trying to decide what to do. I wish I had not touched mine.
 
Kiddo's Driver said:
Nearly the same thread is happening on the Socata.org website. The guy has a plane with 1500 hours on new Slick Mags. No issues. They are running fine. He is trying to decide what to do. I wish I had not touched mine.
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I can guarantee that those 1500 hour mags are going to be a mess inside. I can also guarantee that some day soon he won't be able to start his airplane when the impulse mag gets too weak to spark. And it will happen someplace really inconvenient. At that point, he'll wish he had spent the money (less money, too) earlier.
 
Had a Slick Mag go 2600 Tach hours plus (sold the plane at 2600). Other one was replaced at 2000 just as a precaution (and to get them out of sequence) because I heard a lot of this. Currently have two Slick mags with almost 900 hours on them and 19 years old. Neither have been opened.

Had a friend who flew an airplane where both mags had just been serviced. Both mags failed on the initial flight causing an off field landing (something about too much grease). They happened to be Bendix, but Im not sure thats relevant.

It all depends

Slicks. You don't need to rebuild them. Thats because they are built to be the best they can be! Not saying they NEVER need anything. Sometimes they do. Just try to arrange it so they dont both need the same thing on the same flight. Its called "out of sequence" and it is a well known equipment managment reliability tool.

Lycoming and Slick are a trustworthy combination.

The people that really know this stuff would be ones that manage a whole fleet of indentical airplanes. What I know is just a little above antecdotal really. Take what I say with a grain of salt. I think there is some truth to it. At any rate, the route Im taking with my mags is dont touch so long as they are working. Works so far. Decisions like this are playing the odds. Finding the route with the least chance of failure and saving resources to be applied at the place with the most return. You know, Capitalism!
 
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Exactly, and that's much worse too if it's a backcountry plane, doing a inspection is one of the cheapest things which can amount to a HUUUGE paint in the butt WHEN it bites you in the arse.
 
Kiddo's Driver said:
Nearly the same thread is happening on the Socata.org website. The guy has a plane with 1500 hours on new Slick Mags. No issues. They are running fine. He is trying to decide what to do. I wish I had not touched mine.
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He is all right not doing anything. If he wants to do something he should replace ONE.
 
On these mags and everything really, what we need is DATA. Some accurate record keeping on what fails, and how often and why.

I had some brake discs on my first Husky. And those suckers had deep grooves in them, beyond usability at 1000 hours! And I dont use the brakes all that much. The company that made them had me send my old ones in because they wanted to analyze them. Im pretty sure I got a pair with really soft metal because the next ones never wore much at all. The mfgs need feedback on how long their stuff is lasting. Im not sure how they get it. But it would be an absolute GOLD MINE of valuable information if it could all be gotten somehow.
 
If Slicks were that bad.....we'd have ADs.......and lots of them.
 
My slicks had 1100 hrs on them since last IRAN when I bought plane, I had them serviced at annual for a couple of hundred. That and replacing champion spark plugs with tempest fix my starting troubles.
If you don't trust you mechanic to service both of them, get a new mechanic.
 
Checkout_my_Six said:
If Slicks were that bad.....we'd have ADs.......and lots of them.
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They ain't THAT bad, but there is a large difference between slicks and bendix. Not many working pistons with slicks.

The second one of my mags acted up after I bought my plane I swapped both to bendix
 
James331 said:
They ain't THAT bad, but there is a large difference between slicks and bendix. Not many working pistons with slicks.

The second one of my mags acted up after I bought my plane I swapped both to TCM
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FTFY.
 
My 2 cents. I've one Slick at almost 800 hours and one electronic ignition. It's a PITA to pull the engine and that's what's needed to get to the mag. I have a new Slick to put in once I make up my mind to replace the old one with the new one but the old one continues to act like new and it's easier to just keep putting it off. Anyway, currently at 800 hours and running fine. I like that Socata story :wink2:. I don't feel so negligent now.
 
Dan Thomas said:
I can also guarantee that some day soon he won't be able to start his airplane when the impulse mag gets too weak to spark. And it will happen someplace really inconvenient. At that point, he'll wish he had spent the money (less money, too) earlier.
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Just like mine did 144 hours after I paid QAA to do the 500 hour inspection? I would have been better off letting it ride.
 
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A direct question for the pilot/owners.

How do you know when it is time repair / or / replace?

Your mags of course
 
Tom-D said:
A direct question for the pilot/owners.

How do you know when it is time repair / or / replace?

Your mags of course
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I tried the manufacturer's recommendation (SB3-08A in my case) and had my 500 hour old magnetos inspected by QAA. One seems fine. The other died at 144 hours, and that is just gross.

I'm either going to put new magnetos in every 500 or run to failure. I haven't decided yet. I may put one new in every 1000 and stagger them.

Let's face it, short of a change in magneto drop it is a case of Schrödinger's magneto internals.
 
Tom-D said:
A direct question for the pilot/owners.

How do you know when it is time repair / or / replace?

Your mags of course
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OK, I'll bite....when it economically makes sense......:goofy:

Point is....Slicks are not throw away mags. They are very much repairable and every bit as repairable as Bendix.:yes:
 
Dan Thomas said:
I can guarantee that those 1500 hour mags are going to be a mess inside. I can also guarantee that some day soon he won't be able to start his airplane when the impulse mag gets too weak to spark. And it will happen someplace really inconvenient. At that point, he'll wish he had spent the money (less money, too) earlier.
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So what? Slicks are, and always have been, 'disposable mags', and the only people I know of who were happy with them treated them as such. You adjust and tune them at annual/100h, and replace them when they self destruct or at overhaul of the engine. There have been many sets that made it to engine overhaul with no more than adjusting and maybe a set of points.
 
Checkout_my_Six said:
Point is....Slicks are not throw away mags. They are very much repairable and every bit as repairable as Bendix.:yes:
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Agreed. The flight school I worked at had a bunch of them IRANing them was almost a weekly chore. OTOH, the 500 hour inspection saved us a lot of grief.
 
Henning said:
There have been many sets that made it to engine overhaul with no more than adjusting and maybe a set of points.
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I never had any Slicks self-destruct. They work just fine if they're cared for, exactly like Bendixes. I looked after a lot of Slicks in the flight school, for a long time.

Too many shops don't do the inspections or overhauls properly. The manuals give all the info but they can't read or something. Many, many people don't even understand how a magneto works and what's going on in the electrical end of things, so they aren't acutely aware of what misaligned points or too much cam grease or a bent coil tab can do, along with a lot of other things. Hence, the 144-hour QAA junk.

It's no different than the overhauled Kelly alternators that get way too much grease in the rear bearing, grease that gets out and flies onto the slip rings and messes up the brushes and rings and limits the field current, thus weakening the alternator's output or making it erratic. Saw way too many of those.
 
Checkout_my_Six said:
Point is....Slicks are not throw away mags. They are very much repairable and every bit as repairable as Bendix
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Show me a source for parts and maintenance manual for the early Slicks.
 
which model?...get a good subscription service....and you could have access. This is one easily....obtainable. :D
 
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Checkout_my_Six said:
OK, I'll bite....when it economically makes sense......:goofy:
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Who said anything about economically?

The easy way to tell when a mag needs servicing/replacing is when it starts giving high mag drops, needs the timing bumped up at annual time, or has orange spark that will not jump a 3/8" gap in free air. there are lots of symptoms that a mag is failing, long before they totally fail.
 
Looks like the 600 series OH manual, L-1020-B overhaul manual, is available from Champion.

but.....
Replace all Slick 400/600 Series and 4200/6200 Series magnetos with Slick 4300/6300 magnetos when required.

Parts for 400/600 Series magnetos have been obsolete for several years and, as on-hand stock is exhausted, are not being replaced. If required parts are not available, upgrade to Slick 4300/6300 Series magnetos is required.

Parts for 4200/6200 Series magnetos will remain available until December 31, 2011. After this date, parts will remain available until on-hand stock is exhausted. Following this date if required parts are not available, upgrade to Slick 4300/6300 Series magnetos is required.

Champion will continue to accept Slick 400/600 Series and 4200/6200 Series magnetos for core credit toward the purchase of Slick 4300/6300 Series magnetos until December 31, 2011. After this date, Champion will no longer issue core credits for Slick 400/600 Series or 4200/6200 Series magnetos.
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Tom-D said:
Who said anything about economically?

The easy way to tell when a mag needs servicing/replacing is when it starts giving high mag drops, needs the timing bumped up at annual time, or has orange spark that will not jump a 3/8" gap in free air. there are lots of symptoms that a mag is failing, long before they totally fail.
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Well you have your opinion.....now doncha? :goofy::D
 
Checkout_my_Six said:
Well you have your opinion.....now doncha? :goofy::D
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Ever hear anyone say "the engine will talk to you"?

Is it apparent to you why we IAs are required to run the engine after the annual to insure we get all the proper indications ?
 
yup....we do dat all the time. I also do an idle mag check. I'm a believer....I've found things as a result that were fine at the normal 1,700 rpm check.
 
mechanical....or electric? Many things can change the "effective" spark timing.
 
Checkout_my_Six said:
mechanical....or electric? Many things can change the "effective" spark timing.
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Inside the mag, it's the points gap and cam or rubbing block wear that changes it. Eroding points will advance the timing. A wearing cam or block will retard it. Either one will throw the E-gap off and weaken the spark. The ideal wear rate is for the two factors to cancel each other out.
 
Dan Thomas said:
Inside the mag, it's the points gap and cam or rubbing block wear that changes it. Eroding points will advance the timing. A wearing cam or block will retard it. Either one will throw the E-gap off and weaken the spark. The ideal wear rate is for the two factors to cancel each other out.
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Hopefully the cam outlasts a few sets of points, but yeah, all these parts wear out.
 
Inspect as recommended, overhaul (bendix) as needed or if you have a bad drop.

Slicks are cheaper to replace than rebuild, bendix it makes sense to rebuild.
 
James331 said:
Inspect as recommended, overhaul (bendix) as needed or if you have a bad drop.

Slicks are cheaper to replace than rebuild, bendix it makes sense to rebuild.
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Yeah, I haven't seen a big problem with Slicks when people just get a new set at overhaul. They may see some minor service through to the next overhaul, but so will a Bendix/TCM. I've owned both and am pretty much equally pleased with their overall service and reliability, though I would much prefer electronic ignition and fuel injection.
 
Tom-D said:
Who said anything about economically?

The easy way to tell when a mag needs servicing/replacing is when it starts giving high mag drops, needs the timing bumped up at annual time, or has orange spark that will not jump a 3/8" gap in free air. there are lots of symptoms that a mag is failing, long before they totally fail.
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I knew about the mag drop. The other two make sense. Thanks!
 
Checkout_my_Six said:
mechanical....or electric? Many things can change the "effective" spark timing.
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And anything inside is a service/repair, isn't it? read the question.

The only thing you can adjust inside the mag that would change the engine timing is the points. When you bump up the timing on the mag, you are compensating for point wear, but when you simply bump up the timing you have not cured the dwell that causes a weak spark.
As the points cam follower wears, the gap lessens, which causes the points to open late and close early. which does not allow the coil to be fully charged prior to the points opening thus a weak spark. the way you check for that is to hold plug wire off the plug and snap the mag by its impulse coupling and see how far it will jump. and see what color the spark is.

A new mag of either make will jump a nice blue spark about 1" as you pull the prop thru the impulse snap. older mags will be much shorter, and orange in color.

I draw the line of airworthiness at 3/8", and I do not work on mags any more, the liability is too high, due to the mags having the failure rate that they do.

Carbs fall into this category also.
 
Henning said:
Hopefully the cam outlasts a few sets of points, but yeah, all these parts wear out.
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Bendix's points have a rubbing block that wears. It gets replaced when the points are replaced. Slicks use a plastic cam that comes with a new set of points. It also gets replaced when the points are replaced.
 
Checkout_my_Six said:
...Point is....Slicks are not throw away mags. They are very much repairable and every bit as repairable as Bendix.:yes:
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Slicks carry the "throw away" stigma because they did, at one time, produce a magneto that was not repairable and actually was thrown out at the end of its service life. They no longer make that model.

The more disturbing thing about Slicks was their practice of offering specific discounts on their magnetos if you turned in a pair of Bendix mags for exchange - which they would then destroy.

They no longer do that and of course they have gone through a number of ownership changes since those days but I still carry a grudge even though it is probably no longer justified. Old feelings, beliefs, habits and ways are hard to break sometimes.
 
I can see 3 ADs for slick magnettos on FAA website:

74-18-05 8/28/1974 Magnetos
80-06-05 3/28/1980 Magnetos
81-16-05 8/6/1981 Magnetos

mine are model 4370 and 4371.

I can see that none of these ADs apply to mine. So, unless there is some other fault, the annual should be passed without needing to inspect and overhaul the mags, even if it is passed 500hrs.

Correct?
 
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