The Parking Brake Module (PBM) allows the activation of the A/C brake system for Parking and Emergency braking. The Parking function prevents main wheel rotation with the RPA parked without external source of hydraulic or electrical power. Once Park brake ON is selected, the Park Brake Valve will not require any electrical power to remain in the Park Brake ON state. The same occurs if Park brake OFF is selected. The Park Brake Module is designed also to provide emergency braking during aircraft towing operations. The Park Brake provides an Emergency/Ultimate means to decelerate the RPA on ground in case of failure in the Normal and Alternate Brake Modes.