An emergency park brake system of an aircraft, the emergency park brake system comprising: an emergency park brake controller configured to receive emergency braking input and configured to generate both an emergency braking command and a power supply condition in response to the emergency braking input; an electrical power interface configured to receive electrical power from a power source; an electromechanical actuator; a hydraulic brake valve, wherein the electromechanical actuator is mechanically coupled to and configured to selectively actuate the hydraulic brake valve; a first electrical communication pathway extending between the emergency park brake controller and the electrical power interface; a second electrical communication pathway extending between the emergency park brake controller and the electromechanical actuator; and a selective electrical connection extending between the electrical power interface and the electromechanical actuator, wherein the selective electrical connection is configured to be electrically connected to the electromechanical actuator in response to the power supply condition being satisfied; wherein the electromechanical actuator is configured to actuate the hydraulic brake valve in response to an emergency braking command being received by the electromechanical actuator from the emergency park brake controller by the second electrical communication pathway and in response to the selective electrical connection being electrically connected, wherein the selective electrical connection is electrically connected in response to the power supply condition being received by the electrical power interface from the emergency park brake controller via the first electrical communication pathway and the electrical power interface providing power via the selective electrical connection in response to the power supply condition indicating a power connection. an emergency park brake controller configured to receive emergency braking input and configured to generate both an emergency braking command and a power supply condition in response to the emergency braking input; an electrical power interface configured to receive electrical power from a power source; an electromechanical actuator; a hydraulic brake valve, wherein the electromechanical actuator is mechanically coupled to and configured to selectively actuate the hydraulic brake valve; a first electrical communication pathway extending between the emergency park brake controller and the electrical power interface; a second electrical communication pathway extending between the emergency park brake controller and the electromechanical actuator; and a selective electrical connection extending between the electrical power interface and the electromechanical actuator, wherein the selective electrical connection is configured to be electrically connected to the electromechanical actuator in response to the power supply condition being satisfied; wherein the electromechanical actuator is configured to actuate the hydraulic brake valve in response to an emergency braking command being received by the electromechanical actuator from the emergency park brake controller by the second electrical communication pathway and in response to the selective electrical connection being electrically connected, wherein the selective electrical connection is electrically connected in response to the power supply condition being received by the electrical power interface from the emergency park brake controller via the first electrical communication pathway and the electrical power interface providing power via the selective electrical connection in response to the power supply condition indicating a power connection.