Narrative:

During the cruise portion of our flight at 4;000 ft mean sea level approximately 40 NM from our destination we received a master warning signal with a 'left engine oil press' cwp light. I announced 'left engine oil pressure' and canceled the warning. The first officer and I scanned the engine instruments and noticed the left engine oil pressure was in fact low and I reached for the QRH as he announced 'oil pressure QRH'. During the time it took to complete the entire checklist the master warning signal would continue to light up and sounded a triple chime and would return after being canceled. I began to complete the QRH checklist as we were instructed to contact TRACON. I switched to the assigned frequency. I had completed the QRH up to the point it directed us to note the engine oil pressure to see if it was below 30 psi. The gauge was indicating approximately 20-25 psi with an engine temperature noticeably higher than the right engine temperature. I confirmed by asking the first officer if he agreed with the indication and continued the checklist which guided us to the 'engine shutdown checklist'. While turning to the correct page the flight attendant called. I answered thinking that our issue may be affecting the cabin. She requested we increase the cabin temperature. While I was in contact with her; I advised that we were having issues with an engine and would be shutting it down; our plan was to continue to the airport and would be landing in approximately 10-15 minutes; expect a normal landing with no special instructions nor the need to brace. She sounded very calm and confirmed what I had told her. After hanging up with the flight attendant I contacted ATC and declared an emergency due to a precautionary shutdown of an engine and provided the information he requested. After alerting ATC I completed the engine shutdown QRH checklist. The engine shutdown was successful. ATC asked if we would prefer an ILS or visual at our destination; we accepted the ILS. After the QRH checklists were completed; the first officer and I performed a control exchange and I became the pilot flying for the remainder of the flight. We were vectored to the ILS 34 and commenced an uneventful landing with arff standing by. The remainder of the flight was uneventful.according to company maintenance personal; who inspected the engine after the event; the engine was found to be four quarts low on oil and showed signs of internal damage. I briefly looked over the aircraft logbook and noted that two days prior a crew entered a discrepancy regarding fluctuating oil pressure on the same engine. It appeared the oil system was serviced and returned to the line. Additionally; routine maintenance had been completed. I believe the routine maintenance was completed separately from the oil system being serviced but do not recall for sure. I feel that the previous write up could have been investigated more thoroughly and; perhaps; some type of trend data kept regarding the oil usage of the engine. It is very possible this is already the normal practice as I am not overly familiar with the internal working of the maintenance department.

Related reports:

Google
 

Original NASA ASRS Text

Title: SF340 captain experiences low oil pressure in cruise at 4;000 FT and shuts the engine down. Flight continues to destination where maintenance determines the engine is four quarts on oil and may have sustained damage.

Narrative: During the cruise portion of our flight at 4;000 FT mean sea level approximately 40 NM from our destination we received a master warning signal with a 'L ENG OIL PRESS' CWP light. I announced 'left engine oil pressure' and canceled the warning. The First Officer and I scanned the engine instruments and noticed the left engine oil pressure was in fact low and I reached for the QRH as he announced 'oil pressure QRH'. During the time it took to complete the entire checklist the master warning signal would continue to light up and sounded a triple chime and would return after being canceled. I began to complete the QRH checklist as we were instructed to contact TRACON. I switched to the assigned frequency. I had completed the QRH up to the point it directed us to note the engine oil pressure to see if it was below 30 PSI. The gauge was indicating approximately 20-25 PSI with an engine temperature noticeably higher than the right engine temperature. I confirmed by asking the First Officer if he agreed with the indication and continued the checklist which guided us to the 'engine shutdown checklist'. While turning to the correct page the flight attendant called. I answered thinking that our issue may be affecting the cabin. She requested we increase the cabin temperature. While I was in contact with her; I advised that we were having issues with an engine and would be shutting it down; our plan was to continue to the airport and would be landing in approximately 10-15 minutes; expect a normal landing with no special instructions nor the need to brace. She sounded very calm and confirmed what I had told her. After hanging up with the Flight Attendant I contacted ATC and declared an emergency due to a precautionary shutdown of an engine and provided the information he requested. After alerting ATC I completed the engine shutdown QRH checklist. The engine shutdown was successful. ATC asked if we would prefer an ILS or visual at our destination; we accepted the ILS. After the QRH checklists were completed; the First Officer and I performed a control exchange and I became the pilot flying for the remainder of the flight. We were vectored to the ILS 34 and commenced an uneventful landing with ARFF standing by. The remainder of the flight was uneventful.According to company maintenance personal; who inspected the engine after the event; the engine was found to be four quarts low on oil and showed signs of internal damage. I briefly looked over the aircraft logbook and noted that two days prior a crew entered a discrepancy regarding fluctuating oil pressure on the same engine. It appeared the oil system was serviced and returned to the line. Additionally; routine Maintenance had been completed. I believe the routine maintenance was completed separately from the oil system being serviced but do not recall for sure. I feel that the previous write up could have been investigated more thoroughly and; perhaps; some type of trend data kept regarding the oil usage of the engine. It is very possible this is already the normal practice as I am not overly familiar with the internal working of the Maintenance Department.

Data retrieved from NASA's ASRS site as of April 2012 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.