I made a helicopter with a coaxial main rotor scheme. I also installed a small blade in the back of the case, changed its size to a minimum. but the helicopter began to rotate 360 degrees spontaneously. As you understand, you can't do without an additional blade, but I want to hide it as much as possible. Help experienced experts!:)
@TheFlightGuySP thank you, it helped a lot!
You can do it without a tail rotor, but the two main rotors need to rotate in opposite directions first.