UNSAFE GEAR INDICATION.

Narrative

AFTER BEING CLRED FOR THE VISUAL APCH FOR RWY 16L; I APCHED A 6 MI FINAL AND LOWERED THE LNDG GEAR. THE ACFT GEAR INDICATION SYS INDICATED THAT THE R MAIN GEAR WAS NOT DOWN AND LOCKED. NEXT I TRIED TO 'RECYCLE' THE GEAR. SAME RESULT -- NO R MAIN GEAR DOWN AND LOCKED INDICATION. AT ABOUT A 3 MI FINAL I INFORMED TWR OF THE PROB AND MY INTENTION TO BREAK OFF THE FINAL APCH TO TROUBLE-SHOOT THE PROB. THE TWR INSTRUCTED ME TO MANEUVER E OF THE RWY 16L FINAL TO TROUBLE-SHOOT; WHICH I DID. AT THIS TIME I NOTICED THAT THE GEAR HANDLE WOULD NOT RETURN TO NEUTRAL ON ITS OWN AFTER EXTENSION. ALSO; THE RED GEAR UNSAFE LIGHT WAS ILLUMINATED. I BROUGHT THE THROTTLES BACK AND GOT A GEAR WARNING HORN. THE GREEN LIGHT ITSELF WAS CHKED; TO BE NORMAL. NEXT I TRIED TO MANUALLY PUMP THE GEAR DOWN. THIS DID NOT WORK EITHER. NEXT I TRIED ANOTHER RECYCLE WITH A HIGH PWR SETTING TO GIVE THE HYDRO PUMPS MORE PWR. NEXT I TRIED POSITIVE G-LOADING. FINALLY I ASKED THE TWR FOR A 'FLYBY' ON RWY 16R. I WAS CLRED FOR THE LOW APCH AND THE CTLR SAID THAT THE GEAR APPEARS TO BE DOWN; AND THE GEAR DOORS APPEAR TO BE OPEN. NEXT; I DECLARED AN EMER AND MADE A PRECAUTIONARY LNDG; LNDG ON RWY16L WITH NO R MAIN GEAR GREEN LIGHT. I ALSO ASKED THE TWR TO PROVIDE FIRE SAFETY EQUIP FOR THE LNDG. THE LNDG WAS NORMAL; SO I TAXIED VERY SLOWLY OFF THE RWY AND TO THE RAMP WITH THE FIRE TRUCKS FOLLOWING ME. UPON FURTHER INSPECTION OF THE R MAIN; ON THE RAMP; I REALIZED THE OVER-CTR DRAG LINKAGE; WAS NOT LOCKED. I CALLED A CERTIFIED MECH AND HE INSPECTED THE GEAR AND AGREED THAT THE R MAIN WAS NOT LOCKED. NEXT; HE MANUALLY PULLED THE LINKAGE OVER-CTR; AND LOCKED. ANOTHER DETAIL; AS SOON AS THE ENGS WERE SHUT DOWN; THE GEAR WARNING HORN CAME ON; AND PERSISTED UNTIL THE MASTER SWITCH WAS TURNED OFF. ABOUT 45 MIN AFTERWARDS; 2 FAA OFFICIALS CAME TO INSPECT THE AIRPLANE AND THEY SPOKE WITH ME AND FILLED OUT AN 'OCCURRENCE FORM.'