AIR TFC FACILITY CANNOT CTL APCH LIGHTING SETTING FROM TWR CAB.

Narrative

SIOUX CITY TWR IS UNABLE TO MANUALLY CTL THE APCH LIGHT SETTINGS FOR RWY 13. SINCE THE INSTALLATION OF A NEW CTL PANEL IN APR/92; THE ONLY WAY TWR PERSONNEL CAN CTL THE APCH LIGHTS IS BY THE 'PLT RADIO CTL FEATURE.' IN ADDITION; THE ONLY WAY TWR PERSONNEL CAN TELL WHICH SETTING THE LIGHTS ARE ON; IS A LIGHT BULB LOCATED ON THE OUTSIDE OF THE LOC BUILDING 1 1/2 MI AWAY. UNDER LIMITED VISIBILITY THIS BULB CANNOT BE SEEN FROM THE TWR. WE BELIEVE THAT THIS SIT COULD CAUSE AN ACFT TO GO MISSED APCH BECAUSE OF AN INCORRECT SETTING OR CAUSE A POSSIBLE ACCIDENT; BECAUSE DEPENDING ON THE NUMBER OF XMISSIONS MADE; THE LIGHTS COULD INADVERTENTLY JUMP TO THE HIGH OR LOW SETTING ON THEIR OWN. REPEATED ATTEMPTS TO HAVE MAINT FIX THE PANEL OR HARDWIRE THE LIGHTS HAVE BEEN FRUITLESS. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING: RPTR STATES THAT CTL PANEL ON MALS HAS AN OFF SWITCH AND 3 SETTINGS: A REIL ON/OFF SWITCH WHICH THEY DO NOT HAVE; AN AIR-TO-GND SWITCH; AND A GND-TO-GND SWITCH. THE SYS IS LEFT IN THE AIR-TO-GND MODE ALL THE TIME. FACILITY MOVED TO A NEW TWR IN APR/92 AND THE PANEL HAS NEVER WORKED. MAINT IS AWARE OF PROB; BUT UNABLE TO FIND OUT WHAT THE PROB IS. MGR ALSO AWARE OF PROB AND HAS BEEN TRYING TO GET IT FIXED. NO UCR FILED. THERE IS A WHITE LIGHT ON TOP OF THE LOC BUILDING ABOUT 1 1/2 MI FROM THE TWR CAB THAT SUPPOSEDLY INCREASES IN BRIGHTNESS AS THE LIGHTS ARE STEPPED UP OR DOWN. THE APCH LIGHTS SERVE RWY 13.