[Mike S]

Interesting article just came out in the EAAs "Experimenter" featuring Paul Lipps-----yep, one of us VAFers.

http://www.eaa.org/experimenter/articles/2009-02_elippse.asp

Now the question is---------when is he going to design a prop for our RVs??

 

[n5lp]

...when is he going to design a prop for our RVs??

Already, I guess.

 

[Mike S]

Maybe??

Larry, similar profile, just attached at the other end??

 

[Bob Axsom]

So far, I think it needs more work

I flew in the Wichita AirCap 200 air race against Jim Smith in the plane photographed with the red tipped prop. He had O-320 with this prop and flew in the RV Red class he averaged 166.21 kts or 191.27 mph - that is not a great speed for this elongated triangular course on that day. I was in the RV Blue class with the O-360 and the Hartzell 72" diameter prop with F7666 blades (not blended airfoil) and I averaged 185.16 kts or 213.08 mph. Wind was a factor with a dramatic increase in ground speed by desending from 700 ft AGL to 500 ft AGL so altitude flown could have been a factor in Jim's speed. However, the shape is different from the Ellipse props on the Reno Biplane winners and it appears inconsistent with the material in Jack Norris' propeller book. From what I can see the RV prop it is still a work in process configuration.

Bob Axsom

 

[1:1 Scale]

However, the shape is different from the Ellipse props on the Reno Biplane winners and it appears inconsistent with the material in Jack Norris' propeller book. From what I can see the RV prop it is still a work in process configuration.

That was my first reaction after looking at the picture above