Patent ID: 9511879
Filing Date: 2016-12-06
CPC Classification: B64C,B64D

Claim Text:
1. An apparatus for monitoring doors on an aircraft comprising a system monitor having a circuit with an interrogation switch, a receiver, a plurality of light sources of a first color and at least one light source of a second color, the system monitor receiver tuned to receive a door open signal when the interrogation switch is activated, a plurality of door sensor units, each having a housing with a transmitter, a protruding limit switch, the limit switch having a door-open position and a door-closed position and being in a sensor circuit with a battery such that battery voltage is applied to the transmitter when the limit switch is in the door-open position, so that when the limit switch is in the door-open position transmit a transmission pipe signal with a unique identifier, each door sensor unit having different unique identifier, whereby if the system monitor receives a transmission from one of the door sensor units of a door-open position signal, a corresponding one of the plurality of lights of the first color is illuminated, and if the system monitor receives no signals from any of the door sensor units, the light of the second color is illuminated.