NOSE GEAR DOWN AND LOCKED LIGHT FAILED TO ILLUMINATE WHEN ACR MLG GEAR EXTENDED FOR LNDG AT DEN. APPARENTLY A FALSE INDICATION.

Narrative

AS F/O I WAS MAKING THE VIS APCH TO RWY 26L. SHORTLY AFTER THE OM; I CALLED FOR 'FLAPS 15; GEAR DOWN; LNDG CHK.' WE GOT A GOOD INDICATION ON THE LEFT AND RIGHT MAIN GEAR; AN UNSAFE NOSE GEAR RED LIGHT ON AND NO NOSE GEAR GREEN LIGHT. THE GEAR DOOR LIGHT WAS OUT. WE RECYCLED THE LNDG GEAR AND GOT THE SAME INDICATIONS. WE EXECUTED A MISSED APCH AND ASKED THE TWR TO CHK THE NOSE GEAR. THEY SAID IT LOOKED DOWN; I CONTINUED FLYING THE MISSED APCH FOR A FEW MINS AT WHICH TIME THE CAPT TOOK OVER THE FLYING AND ASKED ME TO REVIEW AND PERFORM THE ABNORMAL PROCS CHKLIST. THE CHKLIST DIRECTED ME TO RAISE THE EMER GEAR EXTENSION LEVEL; WHICH I DID; WITH NO CHANGE IN THE NOSE GEAR LIGHTS (ALTHOUGH THE GEAR DOOR LIGHT CAME ON AT THAT TIME AS IT SHOULD HAVE). IT THEN DIRECTED ME TO CHK FOR A GEAR DOWN AND LOCKED INDICATION THROUGH THE COCKPIT FLOOR VIEWPORT; WHICH I DID. THE VIEW PORT GLASS WAS OBSCURED BY SOME SUBSTANCE AND I WAS UNABLE TO DETERMINE WHETHER THE NOSE GEAR WAS DOWN AND LOCKED. (WE ALSO CHANGED THE NOSE GEAR INDICATOR LIGHTS--NO CHANGE.) THE CHKLIST THEN DIRECTED US TO LAND AND STOP STRAIGHT AHEAD SINCE THE INBOARD GEAR DOORS WERE OPEN. I INFORMED THE CAPT OF THOSE INSTRUCTIONS AND HE ACKNOWLEDGED. IN ADDITION TO ACCOMPLISHING THIS CHKLIST WE ALSO CONTACTED COMPANY MAINT WHO HAD NO IDEAS TO ADD; SO WE REVIEWED COLLAPSED GEAR PROCS; EVAC PROCS; CALLED TWR FOR THE FIRE TRUCKS AND CAME IN AND LANDED UNEVENTFULLY. THE CAPT ROLLED OUT STRAIGHT AHEAD AND CLRED THE RWY ON A HIGH SPD NEAR THE END OF RWY 26. HE THEN SET THE PARKING BRAKE AND DID NOT TAXI UNTIL MAINT ARRIVED AND PUT THE GEAR DOOR PINS IN. APPARENTLY; MINOR DAMAGE WAS DONE TO THE LEFT INBOARD GEAR DOOR.