A BEECH 1900D IN CRUISE DECLARED AN EMER AND DIVERTED DUE TO THE LNDG GEAR WARNING HORN SOUNDING CONTINUOUSLY AND GEAR UNSAFE LIGHT ILLUMINATED.

Narrative

WE WERE ENRTE FROM MIA TO GNV. WHILE IN CRUISE FLT; WE EXPERIENCED A LNDG GEAR WARNING HORN AND A GEAR IN- TRANSIT LIGHT. THESE ARE NOT NORMAL WHILE IN CRUISE FLT WITH THE GEAR IN THE UP POS. AFTER A DISCUSSION WITH MY FO I CONTACTED OUR COMPANY MAINT. THEY INSTRUCTED ME TO PUT THE LNDG GEAR DOWN AND FLY WITH IT IN THAT CONFIGN. IT DID NOT SOLVE THE HORN WHICH CONTINUED TO SOUND. MAINT THEN INSTRUCTED US TO DIVERT TO MCO. THE VISIBILITY HAD JUST DROPPED TO 3 MI SO WE BOTH AGREED ON JAX INTL WHICH HAD CLR SKIES AND 6 MI OF VISIBILITY. IN THE INTEREST OF SAFETY OF PAX AND CREW; WE DECLARED AN EMER WITH JACKSONVILLE APCH. WE FELT IT WOULD BE GOOD TO HAVE ALL THE POSSIBLE ASSISTANCE IF NEEDED. PRIOR TO LNDG THE SIT CORRECTED ITSELF. MY FO AND I RAN THROUGH ALL THE COMPANY PROCS WHICH INDICATED THE GEAR WAS DOWN AND LOCKED. WE OVERFLEW THE JAX TWR AND THEY TOLD US THE GEAR APPEARED DOWN. WE MADE AN UNEVENTFUL LNDG AND THERE WERE NO INJURIES TO THE PAX OR DAMAGE TO THE ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE WARNING HORN SOUNDED CONTINUOUSLY AND THE GEAR UNSAFE LIGHT WAS ILLUMINATED AND NONE OF THE CORRECTIVE PROCS WERE EFFECTIVE. THE RPTR SAID THE FEEDBACK FROM MAINT WAS THEY FOUND THE BELLY OF THE ACFT WITH A LARGE AMOUNT OF WATER WHICH WAS DRAINED AND WHEN TEST FLOWN THE ACFT WAS OK. THE RPTR STATES NO REPEAT RPTS ON LNDG GEAR WARNING ON THIS ACFT. CALLBACK CONVERSATION WITH RPTR ON ACN 381503 REVEALED THE FOLLOWING INFO: THE RPTR STATED WHEN THE LNDG GEAR WAS EXTENDED THEY HAD ALL 3 GREEN LIGHTS BUT THE WARNING HORN STILL SOUNDED. THE RPTR SAID THE CORRECTIVE ACTION BY MAINT WAS TO DRAIN THE ACFT BELLY OF AN EXCESSIVE AMOUNT OF WATER. THE RPTR STATES THE ACFT WAS TEST FLOWN WITH NO LNDG GEAR WARNING PROBS.