AN MD80 ON APCH AT 2000 FT DECLARED AN EMER DUE TO THE R MAIN LNDG POS INDICATOR BLANK WITH GEAR EXTENDED CAUSE UNKNOWN.

Narrative

ON APCH TO SMF; NORMAL FLT; NIGHT; VMC; SOME LIGHT TURB ENRTE; ALL CHKLISTS COMPLIED WITH. CAPT WAS PF. UPON CALL FOR GEAR DOWN WE RECEIVED BOTH MAINS GREEN; NO NOSE GEAR INDICATION. WE RECYCLED GEAR AND RECEIVED L MAIN GREEN; 1/2 NOSE INDICATION ILLUMINATED GREEN; NO R MAIN INDICATION. WE RECYCLED GEAR AGAIN AND RECEIVED SAME INDICATION. WE INITIATED A GAR AND RAN QRH CHKLISTS. CAPT FLEW AND RAN RADIOS. APCH CTL PROVIDED VECTORS AND TERRAIN CLRNC. I APPRISED FLT ATTENDANTS OF SIT AND TOLD THEM TO PREPARE FOR EMER LNDG AND POSSIBLE; BUT NOT PROBABLE EVAC. CAPT DECLARED EMER. QRH COMPLIED WITH; AND VISUAL PORT IN CABIN UTILIZED TO VERIFY R GEAR DOWN AND LOCKED. SEVERAL LOW LEVEL (500 FT AGL) FLY-BY'S MADE TO GET CONFIRMATION OF GEAR DOWN. (DIFFICULTIES TO GET CONFIRMATION ENCOUNTERED DUE TO DARKNESS.) JUST PRIOR TO LNDG; COMPANY CALLED TO ADVISE US TO FLY TO OAK (BIG MAINT BASE). WE DECLINED; LNDG UNEVENTFUL. GND PERSONNEL UNABLE TO LOCK GEAR DOORS UP FOR TAXI IN. WE REPRESSURIZED SYS; BROUGHT DOORS UP AND TAXIED TO GATE. AFTER SECURING ACFT; WE FOUND R GEAR DOOR BACK ON GND. THE LNDG HAD APPARENTLY TORN OFF THE DOOR SKID AND UPLOCK LATCH. DOOR SKIN WAS ALSO ABRADED. NO OTHER APPARENT DAMAGE. NO INJURIES RPTED.