Abstract: A dual mode high intensity aircraft approach lighting system includes a plurality of lights interconnected by means of power wiring. An improved subsystem for detecting lamp failures is disclosed which permits a positive identification of individual failed lamps at a remote location, such as the control tower of an airport, for instance. The subsystem hardware consists of an operational monitor processor, three lamp controllers, one for each of three lighting loops, one remote lamp transceiver module per lamp, and existing ac loop wiring. The operational monitor processor board initiates a reset of the lamp controller and remotely installed transceiver units by sending a SAMPLE ALL signal to each lamp controller. A comprehensive test of all lamps in each of the three lighting loops is performed. The first lamp controller board sequentially polls each lamp for operational status in the first loop.