A B757-200 IN CRUISE AT FL390 DECLARED AN EMER AND DIVERTED DUE TO #2 ENG MINOR STALL AND THEN LOSS OF OIL QUANTITY AND PRESSURE CAUSED BY A COMPRESSOR BEARING OIL SEAL FAILURE.

Narrative

CRUISING AT FL390 AT APPROX XX10Z THE FO NOTICED A RAPID ONE TIME SURGE OF ALL THE R ENG INDICATIONS AT THE SAME TIME I NOTICED A MUFFLED SOUND LIKE A SMALL COMPRESSOR STALL. WE SCANNED ALL THE R ENG INSTS AND NOTICED THAT THE R OIL QUANTITY WAS DECREASING RAPIDLY THROUGH 15 QUARTS. REDUCED THE R ENG THRUST TO IDLE AND BEGAN DSCNT TO FL310. THE OIL QUANTITY CONTINUED TO DECREASE TO BTWN 1-3 QUARTS AND STABILIZED. ENG OIL PRESSURE AND TEMP REMAINED NORMAL AND STABLE. CONTINUED FLT AT FL310 AT REDUCED PWR ON R ENG. AT ABOUT XX35Z THE R OIL FILTER EICAS MESSAGE ILLUMINATED. OIL QUANTITY REMAINED AT ABOUT 3 QUARTS PRESSURE AND TEMP NORMAL. AT ABOUT XX50-XX55Z THE OIL QUANTITY WENT TO ZERO AND THE PRESSURE DROPPED RAPIDLY BELOW THE RED LINE. ACCOMPLISHED ENG SHUTDOWN PROC. DECLARED AN EMER. CONTINUED TO DFW AND LANDED AT XY20Z. NORMAL LNDG WELL BELOW MAX LNDG WT. CFR WAS STANDING BY AT DFW. TAXIED TO GATE UNDER OWN PWR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A B757-200 WITH ROLLS ROYCE RB211 ENGS. THE RPTR SAID THE FO NOTED THE #2 ENG INSTS ALL JUMP UP TO PEAK FOR A MOMENT AND THEN A MINOR ENG STALL WAS NOTED. THE RPTR SAID AFTER THE LOSS OF OIL QUANTITY WAS OBSERVED THE ENG WAS RUN AT IDLE UNTIL THE LOW PRESSURE WARNING LIGHT CAME ON THEN THE ENG WAS SHUT DOWN. THE RPTR STATED THAT MAINT ADVISED THE FAILURE WAS A FRONT END COMPRESSOR BEARING SEAL FAILURE AND THE ENG WAS REPLACED.