A controllable aircraft taxi system is provided that enables the simultaneous control of aircraft autonomous ground movement and direction of aircraft autonomous ground movement. Independently controlled non-engine drive means capable of driving an aircraft landing gear wheel to move an aircraft autonomously on the ground without reliance on the aircraft's main engines are mounted to provide driving torque to aircraft a selected number of main landing gear wheels. The aircraft nose landing gear steering system is provided with steering angle detection and measurement means adapted to communicate with main landing gear wheel non-engine drive means, enabling simultaneous control over both autonomous aircraft ground travel and direction of autonomous aircraft ground travel. The present invention overcomes steering challenges presented by using non-engine drive means on main landing gear wheels to drive aircraft autonomously during taxi.