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Rotax - three blade propeller

E. D. Eliot

Well Known Member
Anyone else notice that a lot if not most of the LSA Rotax powered aircraft with a Rotax engine had three bladed props? They sure look good - sorry that Van's doesn't offer one even if it makes the 12 a little slower. I would buy one in a heartbeat were my 12 kit completed.:cool::cool::cool:
 
There is a school of thought that on an engine with a PSRU, a three blade is far superior for a long life PSRU. Apparently Van or Rotax don't go to that school.
 
3 blade for the rv12

I plan on ordering a Sensenich 3 blade for my Rotax powered 12 - builting as a EAB. But not expected to fly for a few more months.
 
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I own at Aero AT-4 with a 3 bladed prop and think it looks a lot better than the 2 blades on the -12 I am building.
 
We put the 3 blade Sensenich on 331RV after our prop strike, and are ridiculously happy with it. We are at the middle setting, and are getting the same cruise, roughly the same climb, and a much smoother running engine on ours.

If you build EAB (or have an extra 3k to spend after certification!), I'd definitely recommend it.
 
Nothing personal

I just really like the look of a three bladed propeller. And I will probably replace my two blade propeller after flying for awhile if I can afford it.

I'm willing to give up a few knots off the RV-12 legal top speed. My preference is a subjective thing - not science.

Wonder how many RV-12 flyers will retrofit to three bladed propellers - and wonder if Van's will be curious enough to investigate the performance of those who are flying three bladed propellers on their RV-12s?

Judging from the preponderance of three bladed propellers on Rotax powered aircraft at the shows, many manufacturers and home builders like them. Nothing personal. I really don't know why three bladed propellers look so good to me. Some guys like blonds, some like brunettes. I didn't give up anything when I married my beautiful brunette!:cool:
 
Wonder how many RV-12 flyers will retrofit to three bladed propellers - and wonder if Van's will be curious enough to investigate the performance of those who are flying three bladed propellers on their RV-12s?

I suspect very few owners will retrofit based on the 'if it ain't broke, don't fix it' principal.

I would also be very surprised if Vans would be interested in doing any more performance testing or follow-up investigation at this stage, having already done it once and found the three blade prop to be inferior. What I would really like to know though, is which prop did they test?

I know Erich's prop is a 3B0R68C-0, and it would be nice to know if Sensenich supplied Vans the same one or a different model. Van's are unlikely to comment, but maybe Sensenich would?

As has been pointed out, many Rotax's are fitted with 3-blades, and they can't all have been selected just for looks. I'm very interested in the 3-blade option too - mainly for the reported smoother running, although I like the looks as well. I'd buy one based on Erichs reports if I knew for certain that Vans had tested a different type. But I also respect Scott's statements about the lower performance of their prop, so without further confirmation from Vans or the experience of others who have made the switch, I'm still unsure which way to go.
 
I can understand why we would want a three-blade if we were concerned about ground clearance, shorter blades etc....but other than that what is the advantage? Once the pitch was set, if we did get a better climb rate, it could only be at the sacrifice of cruise speed. Is it "curb appeal?"
 
The prop with the least amount of blades is the most efficient. More blades, more drag,
more money.

Total performance sound familiar?

Can't argue the looks though.:cool:
 
That is correct, a single blade is best of all.
In general one should expect a drop in cruise speed and an increased takeoff time and climb - and LOTS SMOOTHER.
All three blade props are not created equal. Viking found the Sensenich to be quite inferior to others, the Warp drive pulling the hardest. Ron gets off the ground far quicker with the Warp than the two blade people. If I recall correctly Vans only tried the Sensenich three blade, they will not share what figures they had with it, but that they would have to re write the POH. Most people seem to agree, the sacrifice in speed (if any) is far outweighed by the smoothness. Shaking everything apart is never a good thing in an aircraft.
 
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I would have any aircraft dynamically balanced after installing the prop and painting the spinner. The two blade should be smooth also.
 
I can understand why we would want a three-blade if we were concerned about ground clearance, shorter blades etc....but other than that what is the advantage? Once the pitch was set, if we did get a better climb rate, it could only be at the sacrifice of cruise speed. Is it "curb appeal?"

Two to go, three to show.
 
I can understand why we would want a three-blade if we were concerned about ground clearance, shorter blades etc....but other than that what is the advantage? Once the pitch was set, if we did get a better climb rate, it could only be at the sacrifice of cruise speed. Is it "curb appeal?"

I think it would be much cheaper to carry around a spare blade and some velcro.
just pop the third blade on while parked.
:)
 
I flew a Remos GX today which has a Rotax and a 3 bladed prop, it felt pretty smooth, I think I even noticed it when shutting down.

Peter
 
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