RV12 E- props install issues

[Scottmcelroy]

Recently installed a three blade E-prop on my RV12is and while performing a power on stall it broke violently hard to the right and immediately entered a spin. Recovered but wasn’t fun. Plane has always stalled very flat with the factory Sens two blade prop. I assume that since this new prop, hub and spinner assembly is approx 6lbs lighter it drastically shifted W&B to a much higher aft CG. Love the performance and lessening torque on start up and shut down on gearbox but don’t feel comfortable now loading any baggage and flying the plane.

Ive heard that they make weights to attach to the gearbox to add forward CG as was required in the Bristol but wondering if that’s the right path. Also my paint job on the plane did add a bit of aft CG as noted with most recent W&B which was done before the prop change. Will do a new W&B and see what numbers come back. Any ideas I haven’t thought of?

 

[seagull]

I also have just recently added the E-Prop. Before getting it I, (penciled), removed 10 pounds off my nose wheel on my current W&B to see the CG change. I was still inside the rear limit with 50#, full fuel, and 2 people.
Also to consider, my current W&B is with an Earth X battery. It removes 10 pounds at the firewall.
I have certified scales and plan on a more accurate check this week.

 

[Scottmcelroy]

I also have just recently added the E-Prop. Before getting it I, (penciled), removed 10 pounds off my nose wheel on my current W&B to see the CG change. I was still inside the rear limit with 50#, full fuel, and 2 people.
Also to consider, my current W&B is with an Earth X battery. It removes 10 pounds at the firewall.
I have certified scales and plan on a more accurate check this week.

Thanks for the info. Have you performed any power on stalls yet? Is your plane painted? I also have the Earth X battery. Our battery removes 10lbs at the firewall?! Oh and I have my prop set at 25 degrees. What is yours set at?

 

[seagull]

Thanks for the info. Have you performed any power on stalls yet? Is your plane painted? I also have the Earth X battery. Our battery removes 10lbs at the firewall?! Oh and I have my prop set at 25 degrees. What is yours set at?

I have slowed it to the edge of the stall where it buffets. To be fair that day I was light in the back, no dog, about 8 gallons, and two guys. Probably in the center of the CG range. It didn’t act differently. I am currently set at 24.7 degrees. I will be putting a new prop on next week, same model. It will be interesting if I notice anything different.

 

[REBRV8]

Rather than guessing what the new CG was after you installed your new prop, it would have been prudent to calculate a new W & B , BEFORE YOU CONDUCTED YOUR TEST FLIGHT, taking into account the change in prop weight. Fly safe.

 

[Brantel]

Since the E-prop has much different characteristics, are you absolutely sure you were remaining coordinated during this power on stall?

 

[Piper J3]

I have E-prop and it requires heavy right foot on climb-out with full power, much more so than 2-blade Sensenich. I estimate 3-4 lbs force on right rudder to center ball...

 

[Brantel]

I have E-prop and it requires heavy right foot on climb-out with full power, much more so than 2-blade Sensenich. I estimate 3-4 lbs force on right rudder to center ball...

I think this may catch some off guard and it does not take much uncoordination in a power on stall to flip into a spin.

 

[12vaitor]

I have E-prop and it requires heavy right foot on climb-out with full power, much more so than 2-blade Sensenich. I estimate 3-4 lbs force on right rudder to center ball...

I concur with the more rudder needed with the E-Prop vs the Sensenich, also had to make some significant trim tab adjustments to get the ball centered in level flight after the change out. No issues with Power On or Power Off stalls during a recent FR with near max gross loading.