 The Alvis Leonides nine-cylinder radial engine was situated in the middle of the fuselage and drove a pusher propeller at the tip of each stub wing and two Rolls-Royce Merlin engine superchargers.The original three-blade tilting hub rotor system was replaced by a two-blade rotor controlled with swashplate-actuated cyclic and collective pitch controls.An empennage provided the necessary stabilization about the pitch and yaw axes.