Question about electric constant speed prop

What happens to a electric CS prop if you have a full power falilure? Thanks

Not positive but I would assume (and we know what that means) that a loss of power would reduce the rpm thereby signaling the prop to flatten the pitch.

Remember an electric prop is not dependent on oil pressure for operation.

Thanks for the response. Let me clear my question. I meant loss electrical power. Even past the back battery. Complete loss of electrical.

MT Prop

On my MT electric constant speed prop, loss of power leave the blades at the exact pitch setting just prior to power loss. No power to drive motor stops any prop pitch change movement. I have noticed on my backup battery duration tests, my MT prop controller is one of the first items to drop out as battery levels decrease.

Steve

steve murray said:

On my MT electric constant speed prop, loss of power leave the blades at the exact pitch setting just prior to power loss. No power to drive motor stops any prop pitch change movement. I have noticed on my backup battery duration tests, my MT prop controller is one of the first items to drop out as battery levels decrease.

Steve

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Got it, than you. How do you like your my pro? I am in a partnership building an RV9a, will have a O-320 (160hp) and he already have the my electric CS to install when the time comes.
I have no experience with the electric CS,

I have an electric MT on my Subaru powered RV7A. I've also had an IVO electric pitch prop in the past.
As Steve noted, loss of power on all electric props I've investigated just leaves the pitch where it is (no energy to change it!).

In general you won't see much difference between an electric vs a hydraulic CS prop. The electric will change pitch slower than the hydraulic, so if you make big changes you will see the difference in response time. But for 'normal' operations this difference is very small.

The protection device for the pitch controller (fuse or breaker) should be accessible to the pilot in flight. That way if the controller has a malfunction it can be disabled (stop potential runaway pitch changes).

For an RV-9A, I would just go with a fixed pitch Catto and sell the electric prop.

With over 750 hours in my -9, I see no real reason for a CS prop. The wing on the -9(A) is a great climber. When I had my 135 HP O-290 up front, I could see climb rates of 1600 FPM at gross on a hot Carolina summer day and cruise speeds of around 140 to 150 knots.

I currently fly behind an O-360, still with a fixed pitch Catto. The only reason I see to add a constant speed prop of any kind on the -9 is if you do a lot of formation work.

RicoB said:

Got it, than you. How do you like your my pro? I am in a partnership building an RV9a, will have a O-320 (160hp) and he already have the my electric CS to install when the time comes.
I have no experience with the electric CS,

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I have > 500 hours on my MT prop with Subaru engine. As Dennis responded, it is a bit slower to respond than normal CS prop, so I take a bit of time with applying power vs. shoving it forward on takeoff, no issues at all in normal cruise power changes. In loops, I have to be careful as it is not fast enough to prevent overspeed unless I pull the power back on downside of loop. The prop is very, very smooth. The 3 blade can give you lots of descent without increase in airspeed when you want (but downside is if you lose an engine, you have a lot of drag out front)

Overall, very satisfied with the prop. Seems to be very high quality. I will be happier at 2,000 hours and no problems.