Boeing, Douglas Products Division P/N 4767461 / AERO INFO, INC. P/N 21-D08-1105

This line checker tests pressurization system electrical and pneumatic-electrical operation, verifies normal operation of the amplifier, actuator, cabin rate controller, cabin pressure controller, outflow valve handle switch and landing gear switch, and monitors amplifier input and output signals. It permits complete electrical checkout and troubleshooting of the cabin pressurization system with the airplane unpressurized, and with the airplane pressurized, a complete pneumatic-electrical check can be made.