RE: Kato adjustable prop
I flew it for a number of years. As far as I know the only ones to compete with it in the USA were Steve Helms and myself.
You need a transmitter that has the special mixing functions for the prop. With that sort of programming you could slightly adjust the high pitch with a side lever on the TX. Then it was set up to go to a higher idle and full flat pitch with the last click or two of low throttle. This would act as a brake on the downlines. But the TX had to have some timing circuits in it so that the prop would not go to flat pitch before the throttle would come down, and that it would go to high pitch before the throttle came up. Otherwise you could blow the blades off it.
Overall it worked very well. But it was difficult to get parts and when the engines got more powerful it was impossible to get different blades to match the engine. Sort of just died out. I sure wish I had kept what I had. Would be fun to play with now.