STC for Pressurized Mags on an M20K

[231LV]

Hi Guys and Gals

I have a quick question which is being asked by my engine overhauler. Does the M20K come with an STC for pressurized mags or was this something installed at the factory? My particular plane  is a 1980 M20K and after searching through all my records, I cannot find an STC for pressurized mags.

[LANCECASPER]

If I remember correctly the 231 didn't come with them in '79 when it was introduced but shortly thereafter, maybe '80 or '81, they started using them.

[LANCECASPER]

Actually it was 1982 that they were added.

I had an '83 with a -GB engine and I knew it had pressurized mags.

[jlunseth]

Is your engine an LB by chance, or a reman GB?  This is just a guess, but the engine was modified to incorporate the pressurized mags, and you could put a reman’d GB or an LB in the plane at TBO.  Those would include the pressurized mags and probably that is in the Type Certificate for the 231, not in a Supplemental Type Certificate.  I would go on the FAA website and look at the TC.  I think that is where you can find it, that’s what I remember, it has been awhile since I have had a reason to look.

My engine is a 2002 reman and has the pressurized mags.  I am sure they simply came as part of the engine, it is an LB.

[jlunseth]

Amend that.  I found the TC and the mags are not mentioned at all, although the ability to substitute the LB for the GB is (Note 17 of the TC). I think where you will find the information on the mags is at TCM, the engine manufacturer.  Type of mag is one of the choices you can make when buying a new or reman engine.

[231LV]

Thank you...this is what I thought I had read, as well. The engine went in as a GB but is being overhauled to an LB

[jlunseth]

If you go on the TCM website and price a new or reman LB, you will see that you get to choose mags, Slick v. TCM mags.  Both are now pressurized.  Then, of course, the engine goes into the aircraft with those mags, which is what leads me to believe that unless something is listed in the TC, it is up to the engine manufacturer what goes on to a particular model of engine.

[jetdriven]

If the parts catalog for your model of engine shows the pressurized mags, then I think that may be your authorization to use them on your particular airplane. That’s how we got around to using Bendix S1200 magnetos on the IO360A3B6 engine. It’s listed in the parts catalog for the engine. As far as I know nobody has ever put 1200 mags on the M20J  and I really was not sure they would fit when I tried it, but they do.  Pressurized mags are a much simpler mod. 

[N231BN]

Both Mooney and Continental address this issue with service letters.

[LANCECASPER]

31 minutes ago, N231BN said:

Both Mooney and Continental address this issue with service letters.

https://cdn2.hubspot.net/hubfs/4147179/technical_documents/service_instructions/sim20-58.pdf?t=1536939446395

[231LV]

Perfect...exactly what I needed...Thank you!

[carusoam]

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on an ordinary Sunday.

Go MS!

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