The cyclic refers to the controls that affect roll and elevator on an RC helicopter. The servos connected to the swashplate are called the cyclic servos, and are generally arranged in a 120 degree configuration for CP helis and 90 degree for FP helis . These servos change the angle of the swashplate, which in turn changes the angle of the blades. As each blade travels 360 degrees, the pitch is changed at exactly the same place in relation to the swash input. This creates more lift on a given side of the rotor, which results in a change of flight attitude of the whole helicopter. The cyclic derives its name from the cyclical changes that a control input produces in the blades as they rotate.
The right stick on a mode 2 radio controls the cyclic.