Mag inspection

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astaib
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Mag inspection

Post by astaib »

Hello,

My mech told me that my mags only have 28 hours remaining before inspection (500 hours).

And he told me that we will do it in 50h at the next 50h visit, but I'm afraid that the 50h visit will take some long days because of this.
He proposed me to buy new one and send back the old one to gain time, but I'm afraid that it will be more expensive, did you do this already?

If it's too much expensive, I want to propose him to wait for my next annual (in approx 100h, this will be 70h after mag 500h potential), is it possible?

And also, I was questionning myself to replace them by Surefly elecronic mag, is it a good idea? What will be the advantages? From what I read it seems that surefly mags are not completely fine on our DA40, did I get it right?
I also noticed that the one who tried only changed one mag to Surefly, why?

Thank you!!!

Arnaud.
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Steve
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Re: Mag inspection

Post by Steve »

Arnaud:

I did exactly what your mech suggested, bought a new pair and switched them out, then subsequently sent the old ones in for inspection/rebuild. There was about a 10 day turnaround for mine. They now reside in my hangar for the next time I have to change them. The 500 hours is a recommendation, not a service limit. By the way, I did mine at about 575 hours, and the airplane didn't fall out of the air at 500. Others will comment on the Surefly, but you still need to keep one Slick mag installed.

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smoss
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Re: Mag inspection

Post by smoss »

Beware, there is a mandatory service bulletin on a huge range of serial numbers/production dates of Slick mags that affects our models that involves replacing the distributor gear. It also applies to any distributor gears that may have been changed over a several year period. Basically, the electrodes come loose and fall off, leading to catastrophic failure of mag. The new design gear has a monel electrode instead of copper, and the design is reportedly much more robust. The MSB came out several years ago, and then was expanded to include almost all of their mags. The MSB came out right after I had replaced my mags with new ones instead of doing the 500 inspections, and I opted to not pull them off again to replace the gears and wait until next 500 hour pull. The Slick folks would never give an actual failure rate, but would instead said it was "significant". Anyways, I just recently did my first 500 hour inspection/repair on these 500 hour new mags, and to my surprise, one of the mags was probably 1 flight from failure, with the distributor electrode totally loose from the plastic, and now free to spin, or fall off. The other was still firmly in place. The mag was always working great, with normal mag checks and ran smooth. So if you have inspected mags sitting around from a few years ago, you may want to change those gears to the new ones before putting them back on!
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astaib
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Re: Mag inspection

Post by astaib »

Hi,

Thank you for the feedback, we have checked the serial number last year for that MSB but I wasn’t in the “wrong” SN luckily.
I will see what is the price difference between having new and making the revision, then I will decide.

But I think that I will push it to the next annual in 1 year.

I still need to understand more about the surefly.

Arnaud.
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Rich
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Re: Mag inspection

Post by Rich »

I had my mags redone in 2015, roughly 175 hrs. (Tach) time past. Today I noticed an abnormally high right mag drop not consistent with its historical performance. I will have to dig in and see if this has the affected distributor block, as it could have been changed during the referenced time period.
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Re: Mag inspection

Post by Davestation »

astaib wrote: Thu Jun 04, 2020 12:11 pm He proposed me to buy new one and send back the old one to gain time, but I'm afraid that it will be more expensive, did you do this already?

If it's too much expensive, I want to propose him to wait for my next annual (in approx 100h, this will be 70h after mag 500h potential), is it possible?
You don’t have to buy new mags, you can get overhauled exchanges at least from a dealer. It will likely run close to double having yours done but you do save some risk of yours needing expensive repairs.

Some shops even carry a spare set of mags so that they can swap out mags for the 500hr at no extra cost.

And also, I was questionning myself to replace them by Surefly elecronic mag, is it a good idea?
The 500hr is a good time to go surefly it but I’d still renew the mag your keeping so it is a viable redundancy. There are a few good threads on here to help you decide whether to go this route.
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