Then - the tail rotor. It is even more difficult. Urals is surely Kamov helicopters involved, and those "tailless" experience on no tail rotor. Tail rotor engaged VV Us. He drew the sheath screw. Inside foam filling. Screw fastening rigid torsion of the blades. I assumed that there will be many problems. He said: "Where did this idea? We had to do a traditional hinge ". Designers insist on their own. I understand: you can not screw in a series start, and he had no resource will be. But while the screw is still set on the first and second prototypes. We flew first with the screw, and there is some crack went neproklei.