A B737-800 AT 7000 FT DECLARED AN EMER DUE TO R MAIN GEAR UNSAFE INDICATION; CAUSED BY HYD FLUID CONTAMINATION.

Narrative

DURING APCH; WE PERFORMED THE BEFORE LNDG CHKLIST. ALL OF THE GEAR INDICATED THAT THE GEAR WAS DOWN AND LOCKED. THEN WE GOT A GEAR UNSAFE LIGHT ON THE R GEAR. WE THEN TOLD TWR WE NEEDED TO GO AROUND AND WORK ON THE PROB. WE DID NOT RAISE THE GEAR BECAUSE WE ORIGINALLY HAD 3 GEAR DOWN AND ASSUMED IT WAS A SENSOR PROB. BY RAISING THE GEAR; WE DID NOT WANT TO JEOPARDIZE WHAT WE HAD. WE THEN TRIED MANUAL EXTENSION TO SEE IF THAT WOULD HELP SINCE THERE IS NOT A SPECIFIC CHKLIST ADDRESSING ONLY ONE GEAR UNSAFE CONDITION. KNOWING IT WOULD NOT COME DOWN; WE DECLARED AN EMER AND PREPARED THE CABIN FOR A POSSIBLE GEAR UP LNDG AND EVAC. WE LANDED ON RWY 7 AT DEN WITH NO PROB. WE STOPPED ON THE RWY BECAUSE WE FELT IT WOULD BE SAFER TO HAVE THE GEAR PINS INSTALLED. IT WOULD HAVE HELPED TO HAVE A SPECIFIC CHKLIST FOR OUR SIT. WITH OUR FUEL GETTING LOW; WE DID NOT HAVE TIME TO CALL MAINT CTL TO TRY ALTERNATE PROCS. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING INFO: THE RPTR STATED MAINT RPTED THE CAUSE OF THE R MAIN GEAR UNSAFE LIGHT WAS CONTAMINATION OF THE HYD FLUID. THE RPTR SAID MAINT WAS PRESSED TO DESCRIBE HOW CONTAMINATED FLUID COULD CAUSE THIS INCIDENT BUT HAVE RELEASED NO FURTHER DETAILS. THE RPTR STATED THIS WAS A NEW B737-800.