Narrative:

During the initial descent, the crew noticed that the oil pressure on the #2 engine had dropped to approximately 52-54 psid, and was fluctuating slightly. The bottom of the normal range is 55 psid. The crew executed the checklist and reduced power to flight idle. We coordinated with maintenance control and agreed that continuation to the destination was logical. We coordinated with the company and the crew reviewed options and contingencies. ATC was advised that our airspeed would be slightly lower than normal, but we did not discuss why. No aural or map were activated. The landing and taxi-in were normal. A low oil level and leakage on the cowl were noted after flight. A puddle of oil formed on the ramp as the aircraft sat overnight. Maintenance repaired a broken carbon seal on the engine oil separator, and we test ran the aircraft, and then ferried home to the maintenance base. The supervisory mechanic at the base told us that this was the third carbon seal that had to be replaced on that engine, and that they were frustrated in finding a solution. When we first 'picked up' the aircraft (on the same day of this event) a mechanic was replacing an oil pressure warning sensor on the #2 engine. The previous crew had gotten a 'low oil pressure' audible warning and the map light, but the gauge was indicating normal pressure. They topped the oil at that time. Oil pressure and quantity indications were nominal for the next 3 1/2 legs.

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Original NASA ASRS Text

Title: EMB120 ACFT DURING ARR DSCNT HAD LOW OIL PRESSURE ON #2 ENG. SINCE THE PRESSURE WAS JUST BELOW THE NORMAL RANGE, THE FLC REDUCED PWR TO IDLE, COORDINATED WITH COMPANY AND CONTINUED TO DEST. POSTFLT CHK REVEALED A BROKEN CARBON SEAL ON THE ENG OIL SEPARATOR. RPTR STATES THAT THIS WAS A CONTINUING PROB.

Narrative: DURING THE INITIAL DSCNT, THE CREW NOTICED THAT THE OIL PRESSURE ON THE #2 ENG HAD DROPPED TO APPROX 52-54 PSID, AND WAS FLUCTUATING SLIGHTLY. THE BOTTOM OF THE NORMAL RANGE IS 55 PSID. THE CREW EXECUTED THE CHKLIST AND REDUCED PWR TO FLT IDLE. WE COORDINATED WITH MAINT CTL AND AGREED THAT CONTINUATION TO THE DEST WAS LOGICAL. WE COORDINATED WITH THE COMPANY AND THE CREW REVIEWED OPTIONS AND CONTINGENCIES. ATC WAS ADVISED THAT OUR AIRSPD WOULD BE SLIGHTLY LOWER THAN NORMAL, BUT WE DID NOT DISCUSS WHY. NO AURAL OR MAP WERE ACTIVATED. THE LNDG AND TAXI-IN WERE NORMAL. A LOW OIL LEVEL AND LEAKAGE ON THE COWL WERE NOTED AFTER FLT. A PUDDLE OF OIL FORMED ON THE RAMP AS THE ACFT SAT OVERNIGHT. MAINT REPAIRED A BROKEN CARBON SEAL ON THE ENG OIL SEPARATOR, AND WE TEST RAN THE ACFT, AND THEN FERRIED HOME TO THE MAINT BASE. THE SUPERVISORY MECH AT THE BASE TOLD US THAT THIS WAS THE THIRD CARBON SEAL THAT HAD TO BE REPLACED ON THAT ENG, AND THAT THEY WERE FRUSTRATED IN FINDING A SOLUTION. WHEN WE FIRST 'PICKED UP' THE ACFT (ON THE SAME DAY OF THIS EVENT) A MECH WAS REPLACING AN OIL PRESSURE WARNING SENSOR ON THE #2 ENG. THE PREVIOUS CREW HAD GOTTEN A 'LOW OIL PRESSURE' AUDIBLE WARNING AND THE MAP LIGHT, BUT THE GAUGE WAS INDICATING NORMAL PRESSURE. THEY TOPPED THE OIL AT THAT TIME. OIL PRESSURE AND QUANTITY INDICATIONS WERE NOMINAL FOR THE NEXT 3 1/2 LEGS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.