Narrative:

In cruise flight, the captain informed me that we may have a problem. She told me the left engine's oil pressure had dropped to 65 psi (yellow arc). She told me to inform ATC that we were declaring an emergency and to ask for vectors for ind. The captain reduced power and continued in the role as PF while I got WX and set up the approach at ind. We reviewed the procedures for a low oil pressure indication and confirmed them with the QRH. We briefed the approach and then briefed the passenger of the situation. The rest of the flight went without further incident, and the left oil pressure remained at 65 psi. Since we had declared an emergency, crash fire rescue equipment was standing by at ind and followed us to the gate. No further assistance was needed. The plane was checked that night by on field beechcraft mechanics, and the next day by mechanics. No major problems were found with the engine except that it was a quart low of oil (this is normal). The engine gauge, transducer, oil filter, and chip detector were inspected but no discrepancies were found. The plane was ferried back to milwaukee the next day.

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Original NASA ASRS Text

Title: AN ACR LTT HAD A DIVERSION TO ALTERNATE BECAUSE OF AN ACFT EQUIP PROB LOW OIL PRESSURE, #1 ENG.

Narrative: IN CRUISE FLT, THE CAPT INFORMED ME THAT WE MAY HAVE A PROB. SHE TOLD ME THE L ENG'S OIL PRESSURE HAD DROPPED TO 65 PSI (YELLOW ARC). SHE TOLD ME TO INFORM ATC THAT WE WERE DECLARING AN EMER AND TO ASK FOR VECTORS FOR IND. THE CAPT REDUCED PWR AND CONTINUED IN THE ROLE AS PF WHILE I GOT WX AND SET UP THE APCH AT IND. WE REVIEWED THE PROCS FOR A LOW OIL PRESSURE INDICATION AND CONFIRMED THEM WITH THE QRH. WE BRIEFED THE APCH AND THEN BRIEFED THE PAX OF THE SIT. THE REST OF THE FLT WENT WITHOUT FURTHER INCIDENT, AND THE L OIL PRESSURE REMAINED AT 65 PSI. SINCE WE HAD DECLARED AN EMER, CFR WAS STANDING BY AT IND AND FOLLOWED US TO THE GATE. NO FURTHER ASSISTANCE WAS NEEDED. THE PLANE WAS CHKED THAT NIGHT BY ON FIELD BEECHCRAFT MECHS, AND THE NEXT DAY BY MECHS. NO MAJOR PROBS WERE FOUND WITH THE ENG EXCEPT THAT IT WAS A QUART LOW OF OIL (THIS IS NORMAL). THE ENG GAUGE, TRANSDUCER, OIL FILTER, AND CHIP DETECTOR WERE INSPECTED BUT NO DISCREPANCIES WERE FOUND. THE PLANE WAS FERRIED BACK TO MILWAUKEE THE NEXT DAY.

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.