Abstract: A model helicopter creates lift using rotor propellers mounted to the rotor arms of a gyroscopic rotor assembly. A controller converts front-back, and left-right inputs into speed control signals used to vary the speeds of the rotor propellers at selected positions of the rotor assembly as it rotates. The varying speed of the rotor propellers at selected rotor positions produces thrust vectors at those positions. The resultant thrust vector determines the direction of the helicopter's flight and enables it to pitch and roll in response to the front-back and left-right inputs. The rotor assembly can have two or more rotor arms, each with a propeller. The helicopter provides left-right yaw control with a yaw propeller on the helicopter body. Electric motors, or motors using other conventional power and speed control methods, can be used to drive the rotor and yaw propellers.