Hello Kriegsmacht !! The WW II-era Flettner 282 Kolibri helicopter used twin two-bladed synchronized intermeshing rotors (similar to Georges Chaulet's Synchrogyro) and did have a rotor tilt system as you mention. It was very successful and stable. There was no tail rotor, and had a rudder (mounted directly behind the engine cooling fan's prop blast) to control yaw. I have long wondered why a model helicopter manufacturer has not produced a miniature of this system. It seems like it would be easier to produce than a swashplate/flybar system. Are you aware of this aircraft ?? Charlie Anderson