My New KiwiPropellers prop
It can finally be made public.
I bought the first prop designed by John McGinnis (Synergy aircraft). It is being made by a new New Zealand company that can be found at: www.kiwipropellers.com
It is designed for my RV-7A.
When I have flown the prop I will do my usual, honest, objective write-up.
The prop is on its way back to Kiwi-land (New Zealand) for a couple of reasons:
1. It will probably be changed so that it can be installed on my RV without a new extension. It's an issue of part of the blades being aft of the base of the hub in the current version.
2. John, the Mitchells and I all agreed on a good ground-testing plan which will precede putting it on my airplane.
The prop was a big hit at AirVenture and many people expressed interest in having one designed for their airplanes - some of which are not RV's.
Here are some things that I learned about it:
One more thing: a few people tried to compare it to a Paul Lipps prop. I mean no disrespect to the late Mr. Lipps, but, no, that's not even close.
- constant Reynolds number
- 25 custom NLF airfoils blended, all by Synergy designer John McGinnis
- some L/D ratios on some of the airfoils that are so high I won't say them out loud, here.
- lift distribution more parabolic than elliptical
- makes good use of the "q" near the hub
- twist is less than "normal" because the necessary advance ratio is accomplished with airfoil design.
- The airfoils adapt in thickness, camber, and design Mach number as they move outward. Keeping the Reynolds number constant prevents unnoticed lift/drag changes as those factors are varied in pursuit of the desired lift distribution.
- all composite construction - no wood
- I have not seen it yet but there will be a custom spinner with it
I look forward to seeing how this new prop works.