VAF Forums - Looked at the new three-blade prop

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- - Looked at the new three-blade prop (https://vansairforce.net/community/showthread.php?t=173720)

3 bladed Fan Boy

Quote:

Originally Posted by AeroDog (Post 1362198)

After being at the show all week, I finally saw the new prop at the Van's tent. It has the same diameter as the two-blade prop, and therefore a much narrower chord. It reminds me of the props I see down at the south end of the field at the ultralight strip, whereas the standard two-blade prop looks much more substantial. Supposedly the three-blade is a bit lighter (didn't expect that) and has a slight performance improvement in some areas, owing, I guess, to the higher aspect ratio of the individual blades. Speaking to the Van's crew, I get the feeling that they think the performance is a toss up. I've decided to stick with two blades.

Jerre

I came away with some opinions after seeing it at OSH, but fist let me say that I was a big fan boy when I first head about the idea that 3 bladed prop might be a great option. Now I have seen the finish product in person and I'm not as impressed, Here are my observations.

Pros. Is the coolness factor. Thats it, that's the only thing.

Cons;
Going to pay another 2,000 or so more on top of the engine kit for a little less noise and 40 FPM increase in performance.

So for this 3 bladed Fan Boy, I will have to pass, for now.

Quote:

Originally Posted by AeroDog (Post 1362402)

The three-blader I saw wasn't mounted on an airplane. All the 12s I saw fly had the two, I think. I would think the acoustic signature would be a bit different.

Jerre

The factory RV-12iS with a 3 blade that flew to OSH was on display all week in front of the Rotax booth.

Photo taken at one of the enroute stops......

https://www.facebook.com/vansaircraf...g&__tn__=EHH-R

A more close-up view taken before it left for OSH......

https://www.facebook.com/vansaircraf...&__tn__=EEHH-R

Fuel consumption 912iS ULS vs iS motor to Oshkosh and home

Did anyone note what the difference was in fuel consumption going to and from Oshkosh in identical RV-12 iS planes with ULS carbed vs iS fuel injected motors? I do understand one of them had a 3 blade prop, but for comparison purposes, let's ignore that difference in performance.

Quote:

Originally Posted by NinerBikes (Post 1362662)

I am not aware of any ULS powered iS version of the RV-12 that are flying yet (and I think only 2 or 3 are being built).

The two company RV-12iS airplanes that flew to OSH together are both 912iS powered.
The only difference is the propeller and the Avionics (one Garmin, one Dynon)

Since the props were both adjusted to get the exact same RPM at max throttle in ECO mode, my guess is that the fuel burn was pretty much identical but I haven't heard the details yet.

They will be a flight of 3 coming home (the One Week Wonder airplane is coming out west for a visit) so there will be additional comparison data (though I have no idea at this point how the prop pitch is adjusted).

I also checked out that prop at Osh. I cant see spending that much money to gain 40’ per minute climb. As far as the “cool factor”, that prop looks like it belongs on a powered parachute. Not my idea of cool. No thanks!
Alex

Quote:

Originally Posted by rvbuilder2002 (Post 1362550)

Scott do you have any performance numbers from the 2 planes that flew together to Oshkosh? 3 blade vs 2 blade