Aircr Hydraulic Wheel Drive Unit

An item consisting of one or more hydraulic motor assemblies specifically designed to mount on and drive aircraft wheels by friction or geared contact; a towed or self-propelled wheel mounted hydraulic pumping unit for supplying hydraulicpower to the hydraulic motors. It has means for direct and/or remote control. The unit is used to propel aircraft on the ground when the aircraft engines are not being operated. May have facilities for furnishing electric power and/or pneumatic power to the aircraft.