Most radio control helicopters use a common layout, with one large main rotor on top generating lift, and a small tail rotor. This is called the Sikorsky layout.

When the rc heli’s horizontal main rotor turns generating upward thrust, it also generates torque which causes the helicopter to rotate in the direction opposite to the rotation of the main rotor. This is countered by sideways thrust generated by a vertically mounted tail rotor. An explanation about the way this works can be found in the Antitorque section of the helicopter article on Wikipedia.

Also, by varying the thrust produced by the tail rotor the RC heli can remain in one position, or intentionally rotate clockwise or counter-clockwise.

An example of a conventional RC helicopter is the eXtreme 450 Brushless 3D electric helicopter made by Thunder Power RC. Smaller examples include indoor mini helis and mini bell IR helicopters.