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3-blade or 2-blade?

J

jn534

I'm New Here
I've just joined the forum (though I've been reading it for a while) since I'm getting ready to order a new RV 12is SLSA and wanted to see what the most recent opinions are on the 3-blade versus the 2-blade props are on the RV 12 with the 912is engine? I've read some posts from the past that indicated that there were some benefits to having the 3-blade prop as things were a bit smoother. While I can certainly appreciate having a smoother ride with one more blade per revolution, it is now a $2000 option (inflation strikes again) and I'm wondering if it is worth the cost. I definitely like the look of the 3-blades on the front of the plane but understand that some have some issues with maintenance getting the bottom cowling off.

Thought's (I know pilots are often shy about expressing their opinions but maybe you can all make an exception in this case)?
 
I went with the 2-blade, then switched to the 3-blade E-prop after about 20 hours. Haven't regretted it for a second. The maintenance issues with the 3-blade are not that bad. You just have to be a bit more careful when removing/installing the lower cowl. A second set of hands makes it easier.
 
+1 on the E-Prop, smooth and no dynamic balancing required. I expect that is not an option for an SLSA RV-12, you have to use Van's approved parts.
 
Our school kit came with the 2-blade. If I were building for myself, I would order the 3-blade because if I didn't, I would think about it and wish I had the other one every time I opened the hangar door. From a practical standpoint, the two-blade is the obvious choice; from an aesthetic standpoint, the three-blade wins big.
 
My E-Prop now has ~40 hrs and it is very nice improvement over the 2-blade Sensenich. The E-Prop has a carbon fiber pitot tube that runs in a ball bearing completely unsupported by the spinner. In fact, you can run prop and pitot tube without installing spinner. Total weight of prop, hub, spinner, pitot, and all hardware is 4.4 lbs. Most airplane fixed-pitch props are pitched for Climb, Cruise, or Combination Climb/Cruise. The carbon fiber E-Prop is ground adjustable fixed-pitch, but the prop tips flex in flight depending on prop loading. In climb… the prop is loaded heavily and the tips flatten out a little bit and prop behaves like excellent climb prop. When you pitch-over into cruise flight the prop unloads and prop tips revert back to static pitch setting and you then have excellent cruise performance. The prop comes dynamically balanced from the factory and is extremely smooth...
 
Welcome to the RV-12 community, where almost every question brings out the E-prop brigade whether it's appropriate or even relevant! Someday, if Van's were to ever approve the E-Props for the aircraft, that would be a good time to evaluate the various claims and consider a change. It seems to be a great option for the E-LSA. You could also do this if you chose to switch over to E-LSA status, which is a whole different can of worms.

You seem to be familiar with the cowling issue. It's a little bit of a pain but eventually you learn to push the wheel all the way to one side and fish the cowl off in the other direction. Even with that the 2 blade would be much easier. The other side of the maintenance coin is that the 3 blade can be removed/replaced while remaining intact and would not require re-pitching. This is uncommon, but still an advantage. Most people who have experience with both thing that the 3 blade is smoother.

The main reason to spend the money is that it just looks way cooler!
 
I went with the three blade sensenich. Since my engine kit just arrived three weeks ago I can’t tell you anything about my experience, let alone compare.

What I do know, though, that years ago I was in an aero club in New Mexico and we had some T-41C with a climb prop and some with a cruise prop. Since I wasn’t able to tell the difference as long as I didn’t know which plane had which, my thought was as follows:
- I think, I would be able to test fly and measure a difference between the two and three blade prop, but I do not expect to be sensitive enough to experience a big performance difference on a day to day basis
- I hope the three blade prop might run a little smoother, since it doesn’t have counter blade (but who knows)
- I will initially try to set it up for cruise, since I will usually stay well below the RV-12is’ service ceiling (but that can be easily changed)
- The three blade prop looks better

IMHO the one big thing for a two blade prop is, if you are planning to store it in a trailer, the two blade prop can just be turned horizontal, while the three blade prop always needs some space upwards. So fitting a trailer to the plane seems to be easier with a two blade prop.
 
Baron71 said:
I went with the three blade sensenich. Since my engine kit just arrived three weeks ago I can’t tell you anything about my experience, let alone compare.

What I do know, though, that years ago I was in an aero club in New Mexico and we had some T-41C with a climb prop and some with a cruise prop. Since I wasn’t able to tell the difference as long as I didn’t know which plane had which, my thought was as follows:
- I think, I would be able to test fly and measure a difference between the two and three blade prop, but I do not expect to be sensitive enough to experience a big performance difference on a day to day basis
- I hope the three blade prop might run a little smoother, since it doesn’t have counter blade (but who knows)
- I will initially try to set it up for cruise, since I will usually stay well below the RV-12is’ service ceiling (but that can be easily changed)
- The three blade prop looks better

IMHO the one big thing for a two blade prop is, if you are planning to store it in a trailer, the two blade prop can just be turned horizontal, while the three blade prop always needs some space upwards. So fitting a trailer to the plane seems to be easier with a two blade prop.
Click to expand...
Thanks to everyone who provided feedback. I'm taking delivery on my RV-12iS at the end of this month. I spent the extra on the 3-blade prop as, like several pointed out, it looks better to me than the 2-blade prop. It will have everything Mosaic compliant but I won't be able to get it certified as such until after Mosaic takes effect in late July. After that I'll need to take the plane back to the factory to get it recertified as Mosaic compliant.

The biggest visible difference for this model year, if you haven't seen it yet, is that the pitot tube is on the wing now instead of the spinner. Aside from the new paint scheme, that's the most visible difference from previous year versions of the plane.

I can post pictures of the plane once I get them if people are interested.
 
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