What? Although I'm no aeronautical engineer, the "best" prop would seem to depend upon many things other than the rotational kinetic energy or moment of inertia of the prop. Propeller efficiency is very complicated and according to people I am acquainted with, who know far more than me, it's subject to much experimentation. Once the prop is up to speed, the kinetic energy of the prop remains constant (apart from changes due to RPM changes), none of the engine's energy is "lost" in the prop due to its moment of inertia. At least that's the way I see it. APC's are quieter, which means less energy is lost to sound and their pitch is relatively true. I like Graupners, but the two I have are big wide bladed props, meaning they wont turn high rpm's, but will pull well at lower rpm's, hence my use of them in a big bipe. My preference for 40 - 120 sport planes, APC.


Edit for grammar, Duh!