Craneplaneguy,
Lookin' good, there. One day, maybe you should explain that screen name. 8)
'Way back in the day, (as in WW-I), there were no variable-pitch props, at least not the hydraulic or mechanical types. They still wanted (needed) them, to make the best use of those engines. They came up with props that would flex to a more shallow pitch at higher RPM,so the engines could pull hard on the ground, and then run faster in flight. Can't say who or where right now, but some ultralight company has been making these flexing "variable-pitch" props again lately, from composites, as a cheap way of getting the advantages without the weight, cost, and complexity of variable prop hubs. Just a thought . . .