Electronic Ignition STC - M20J/ -A3B6D

[d0tnet]

So I have searched and read the threads on EIS and the now available STC options.  However, the actual number of folks purchasing either the Electroair or LASER EIS seems to be limited.

 

I have read the reports from CAFE Foundation but my interest in this system are not aligned with the fuel savings marketing strategy.

 

The short and skinny - the single point of mag failure on the -A3B6D has me a bit on edge.  I understand the mag drive is not under load and 500 HR inspections of mags should suffice.

 

Will an EIS system offer the extra level of reliability/peace of mind I am looking for short of replacing with a A3B6?

 

Any extra measures or alternatives to addressing these concerns?

[FloridaMan]

I don't know if I would just count on inspections if I had that dual mag; I would probably insist that gear gets replaced at some interval. Although that Mooney that went down in the Devil's Golf Course crashed because the dual unit wasn't properly tightened. 

 

I make it a point to be tightly connected with the maintenance of my airplane and to work with mechanics that want to involve me. 

[carusoam]

How many dual mag failures are there compared to the number of electronic ignition failures...

We need to use some level of logic when making machinery decisions.

Not saying that it is improper to fear the dual mag with decades of proper experience on thousands of Mooneys.

It would be improper to assume the electronic ignition with limited experience on Mooney's would somehow be better.

Essentially they are installed and maintained by the same people.

Now, if this makes you uneasy....get to know your mechanic.

Best regards,

-a-

[jetdriven]

RV guys will run a single electronic ignition in the spot where the magneto goes. Basically the single And dual Bendix mags have the same size shaft and gear where it goes in the case. Then they run a hall-effect trigger on the front of the case with a magnet in the spinner. In effect, a dual ignition.

I don't think that will be an option for certified airplanes but it is doable

[Bob - S50]

Will an EIS system offer the extra level of reliability/peace of mind I am looking for short of replacing with a A3B6?

 

Any extra measures or alternatives to addressing these concerns?

If I'm not mistaken, most of the electronic ignition systems replace one of the mags with the electronic system and leave one mag in place.

 

I also believe that if we have an A3B6D engine (like mine) the accessory drive case only has one place for a mag.

 

That would mean in order to install the electronic ignition we would have to replace the accessory drive case with one that allows for two separate magnetos, essentially converting it to an A3B6 and then adding the electronic ignition.

 

Am I wrong?

 

Bob

[OR75]

If I'm not mistaken, most of the electronic ignition systems replace one of the mags with the electronic system and leave one mag in place.

 

I also believe that if we have an A3B6D engine (like mine) the accessory drive case only has one place for a mag.

 

That would mean in order to install the electronic ignition we would have to replace the accessory drive case with one that allows for two separate magnetos, essentially converting it to an A3B6 and then adding the electronic ignition.

 

Am I wrong?

 

Bob

I believe you are right. Can only be an option on a non-D engine

[aaronk25]

I'd love to have a electronic a ignition system that added additional redundancy.

From a safety stand point I'm with Anthony. If the dual mag is inspected every 500 hours and torqued to the proper spec, they do not have a history of failing.

The annoying feature of the setup is after a few hundred hours the timing between the mags gets off 2-3 degrees. The dual mags together can be advanced or retarded, but they can't be independently adjusted.

If the internal timing has drifted It can be heard in climb if one mag is turned off as the engine gets smoother.

Seriously though airplanes are not falling out of the sky when proper maintence is administered.

To help with the uneasy feeling you only have one crank shaft, one gear that drives both mags on a separate mag system, one fuel injection servo (which failed on me).

[PTK]

...The short and skinny - the single point of mag failure on the -A3B6D has me a bit on edge. I understand the mag drive is not under load and 500 HR inspections of mags should suffice.

Relax! Consider the following:

1. As others have said, no matter how many mags you have there's only one gear that drives them from the engine. If that fails all the mags go. No matter which setup you have.

2. Inherent mag problems involve inner components. Things like the points, rotor, and coil etc. The dual mag does have independent and thus redundant such components.

3. You can't find any NTSB data concluding that the dual mag is any less dependable or fails more frequently.

4. The clamps that hold mags to the case have loosened and been blamed for accidents. This is true of any mag setup. Following proper maintenance is crucial.

5. Equally crucial is to recognize and isolate a bad mag. Flyon and land as soon as practicable, to quote the POH!

I'd be concerned more about availability of non aftermarket parts with the dual mag than anything else! Things like case, magnet assembly or impulse coupling springs.

[aaronk25]

I had the chance to convert to seperate mags at overhaul but that Kent doing business with Lycoming, and given how they have treated my friends and me after purchases, I try to minimize my business with them.