MT electric governor?

[rdamazio]

I've started reading up a bit more on engines, props, governors and such (I'm still halfway through the fuselage, so just researching).

I noticed that MT has an electric governor option, which technically gets rid of the mechanical prop lever in favor of any electronic controller. I think for the IO-540 that'd be model P-863-5 (vs the usual P-860-5).
As someone who used to fly FADECs, having one less lever on the quadrant sounds appealing, but I'm probably oblivious to the difficulties and downsides of installing and maintaining that.

Any pros and cons of the electric? Has anyone actually used one in their plane?

Thanks!
Rodrigo

[rocketman1988]

I spent a considerable amount of time researching this option. In the end, with the concurrence and recommendation of MT, I decided on the hydraulic. MT did not recommend the electric system for this application.

If you want less levers on the quadrant, go with EFII. No mixture lever needed...

[rdamazio]

Originally Posted by rocketman1988

I spent a considerable amount of time researching this option. In the end, with the concurrence and recommendation of MT, I decided on the hydraulic. MT did not recommend the electric system for this application.

If you want less levers on the quadrant, go with EFII. No mixture lever needed...

Thanks, that's very useful to know.
Yes, I'm already going with EFII I was hoping for single-lever.

[jcaplins]

Originally Posted by rdamazio

Thanks, that's very useful to know.
Yes, I'm already going with EFII I was hoping for single-lever.

I have an electric CS prop, but not an MT.
Electric props in general are much slower to respond than hydraulic and have a tendency to "hunt". If you have an option to go hydraulic then I don't feel there is any up side to having electric.

I don't know if this applies to the MT electric prop governor, and would be interested to know.

[DGlaeser]

I have an electric MT with the constant speed controller on my Subaru engine, on my RV-7A. For normal flying it works perfectly. I?ve never experienced any hunting and the rpm stays constant during climbs level-offs, and descents.
I don?t do aerobatics which would require quick response from the prop.
If I had the option of hydraulic, I would have gone that way, but I am not disappointed in any way with the electric controller.

[rocketman1988]

If I remember correctly, I think the electric is also heavier...

[rdamazio]

Yes, according to the Van's engine order form, electric is 6 times slower, but this is a -10 (IO-540), so acro is not a concern.

[rocketman1988]

Also, you need to consider which prop. The MTV12 that Vans recommends is rated for 300HP max. If you are going with a tuned engine, CAI, and EFII, you will likely be right near 300HP.

The MT guys I spoke with recommend going to the MTV9 prop as it is rated for up to 450 HP. They said that the MTV12 is fine for the stock 260HP with a generous margin but running up against the max rating at 300 HP, well, they didn't seem comfortable with the drastically reduced margin...just an FYI.

[rdamazio]

Originally Posted by rocketman1988

Also, you need to consider which prop. The MTV12 that Vans recommends is rated for 300HP max. If you are going with a tuned engine, CAI, and EFII, you will likely be right near 300HP.

The MT guys I spoke with recommend going to the MTV9 prop as it is rated for up to 450 HP. They said that the MTV12 is fine for the stock 260HP with a generous margin but running up against the max rating at 300 HP, well, they didn't seem comfortable with the drastically reduced margin...just an FYI.

Ah, I just noticed the "290HP Barrett" on your signature that's a choice I haven't made yet (I know I want an IO-540 rather than something exotic, but haven't settled on the details).

What do you lose by going with the MTV9 instead of the 12? Weight? Thrust?

[rocketman1988]

Well, the biggest loss is cash...the MTV9 is a little more expensive.

The gain is in weight, about 11 lbs heavier and, according to the techs, reliability of the prop...I am just relaying the message I received, YMMV