A high-speed vertical take-off and landing aircraft has a lifting structure, a first rotor with a first and second blade, a second rotor with a first and second blade, an auxiliary propulsion unit for providing forward thrust, and a control system for controlling the pitch of each of the rotor blades. The aircraft has a first, rotor-only, flight mode for hovering and low speed maneuvering. It also has a second flight mode where the rotors are held in at fixed azimuth angles and forward thrust is provided by the auxiliary propulsion unit. Three axis control is provided during the second flight mode by adjusting the attack angles of the fixed rotor blades. Between these two flight modes, there is an intermediate flight mode covering a fully controlled transition between the first two flight modes.

A rotor blade pitch actuator has a first and second motor configured to control the rotor blade pitch. An actuator control system is configured to drive the first and second motor such that backlash is either eliminated from the system or minimized to an acceptable level.