B&C Backup Alternator for the 231

[jlunseth]

We had some discussion awhile ago about this but I searched and could not find anything recent. The issue is that the 231 has a single battery and single alternator, and the alternator is not 100% dependable. The usual problem is a failure of the alternator coupler. The alternator is direct drive, the coupler acts as a clutch to allow slippage if the alternator should seize so the engine will not be damaged, and the coupler can just wear out. 

Apparently B&C makes a backup alternator. The vacuum pump needs to be removed and the B&C is then added on the accessory pad in its place. It can supply 20 amps constant, if the primary alternator goes out. Some of us (me) are not enamored with backups built in to instruments that might on a good day go an hour. Not an option in IMC in some places where I fly. And so there is a limit to how much electronics one can add, and a serious decision to be made about whether the vacuum should be removed, and with it an AI that operates off a non-electrical source. My current system is two 275's, one as primary ADI and the other as primary HSI, with backup. They are being installed in the "two 275" configuration so if the ADI should fail the HSI can revert to an ADI, and then there is the backup as well. But still, I have a standby AI that runs from the pump.

I tried to get a B&C alternator installed by Lasar. They had an older 337 that had been approved, to add a B&C to, I believe it was a 262. But when we took that to the FSDO they said no, that there was some kind of new policy requiring an STC. Now, that was during COVID and they maybe were not very interested in working on much of anything.

Then last month Aviation Consumer came out with an article about the B&C alternator, saying it was STCd for a number of aircraft and that the company is willing to work with individual owners who want to get a 337. I am interested if there is any indication the winds have changed at the FAA since COVID.

At any rate, I am wondering if there are any 231/261 owners here who have had success in getting the B&C alternator approved for their aircraft by 337 in installations where the vacuum pump would need to be removed?

 

[201Mooniac]

I'm told it depends on which FSDO but the Sacramento FSDO has apparently told the shops (Top Gun and Lasar before the move) that they will no longer do field approvals.  I have not tried elsewhere so I'm not sure if it is any better.

[carusoam]

JL,

The challenge with the search function around here…

Three letter words are too small….  B&C

Using Google to search MooneySpace is a pretty good work around…

Sometimes search the term like… B&C alternator

 

I did one…

The good news… there are lots of Continentals that have the second alternator…

I think Lycoming, not so many… (?)

Best regards,

-a-

[LANCECASPER]

9 hours ago, carusoam said:

The good news… there are lots of Continentals that have the second alternator…

I think Lycoming, not so many… (?)

Every Bravo came with two identical 70 amp, belt driven alternators on the Lycoming TIO-540-AF1A & AF1B, but I don't know of any dual alternators on the smaller Lycomings on J's. etc.

[Pinecone]

252, I think an option, for dual alternators.  Mine has this.  One belt driven, one off the accessory case.

Small Continental.

[jlunseth]

Thanks Anthony, I did try that but a 337 needs to be specific to the particular installation. I found some things on the B&C alternator, but not anyone who had succeeded in adding one to a 231/262. I think B&C has an STC for Bonanza’s, 210s and maybe one other non-Moooney, but not for Mooney’s. When I read in Aviation Consumer that they were helping owners with 337s I was hoping someone succeeded where my effort had failed. Probably not.

[N231BN]

It is worth a call to B&C to see if they have a previous 337 for a M20K. I mentioned in another thread I was able to get a field approval for a B&C installation in a 182RG during COVID so it can still be done.

I was thinking of doing one in my 231 but have decided to get it ready to sell instead.

[jlunseth]

Yes, that is my next step. The article in Aviation Consumer says they will help owners with a 337. Maybe they have a few that have succeeded. 

[201Mooniac]

Here is the 337 that Lasar did for an M20K337_BC410_Mooney_M20K_N44CG.pdf

[LANCECASPER]

@jlunseth, 

@201Mooniac posted a 337 above which should be very helpful

[jlunseth]

Thank you. I am putting in a new engine this winter so it is a good time to see if this will work.