A first actuator drives a control surface by being operated by supply of pressure oil from a first aircraft central hydraulic power source including a first aircraft central hydraulic pump. The brake element is pressed against the brake surface by means of the magnetic actuator. There are leads from the lights to a battery storage area, and a battery is in the battery storage area. The compartment may be accessible when the one of the wheels is moved to an open position. When the first power-on signal is switched from a disabled status to an enabled status, a first pulse width modulation signal having a higher or the maximum duty cycle is transmitted from the first power supply control circuit to the control terminal of the first switching circuit, thereby enabling the first output power circuit. Timing continues to be performed using only pattern members of like polarity, due to physical restraints, but the use of two polarities allows additional information to be encoded in the pattern more efficiently.