ACR CARGO ACFT HAS GEAR UNSAFE LIGHT ACTIVATED EVEN WITH 3 GREEN.

Narrative

WHEN CALLING FOR 'GEAR DOWN; FINAL CHK' GEAR WAS LOWERED AND 'GEAR UNSAFE' LIGHT FAILED TO EXTINGUISH WHEN GEAR CYCLE FINISHED. 3 GREEN WERE ILLUMINATED AS WELL. MISSED APCH WAS EXECUTED AND WE HELD TO THE N OF YXU CLASS D AIRSPACE. NUMEROUS ATTEMPTS TO RESOLVE SIT IN COORD WITH COMPANY MAINT AND CHIEF PLT VIA RADIO CONTACT THROUGH YXU AND CTLR WERE UNSUCCESSFUL. YXU TWR AUTH OVERFLT OF ARPT FOR VISUAL INSPECTION OF GEAR POS AND CONFIRMED IT TO BE LOWERED. AFTER DETERMINING THAT ALL RESOURCES HAD BEEN EXHAUSTED IN TROUBLE-SHOOTING 'GEAR UNSAFE' WARNING LIGHT. A LNDG DECISION AT YXU WAS MADE ON THE BASIS OF WX DETERIORATING AT HOME BASE; FUEL REMAINING; AND GOOD ARPT CONDITIONS. A NORMAL LNDG FOLLOWED BY UNEVENTFUL TAXI WAS END RESULT. FORTUNATELY; HAVING PLENTY OF FUEL; FAIR WX AT YXU; AND CTLR COOPERATION GAVE US PLENTY OF TIME TO EVALUATE AND TROUBLE-SHOOT CONDITION. WE WERE CONFIDENT THAT EVERYTHING WE COULD DO HAD BEEN DONE BEFORE LNDG. ONE HINDRANCE WAS OUR INABILITY TO CONTACT ACR FOR DIRECT RADIO COM DUE TO OUR ALT. YXU GND CTLR WAS HELPFUL IN RELAYING INFO FROM HIS LAND-LINE TO OUR COMPANY.