Narrative:

On climb out number one engine oil pressure was observed high; but within limits. As climb continued oil pressure exceeded normal limitations. High oil pressure checklist completed and power reduced on number one engine to keep oil pressure within limits. Notified ATC and stopped climb at FL360 because of reduced power; continued climb was not possible. Oil pressure continued to climb above normal operating limits; power reduced. At FL360 and .62 mach we made the decision to divert to an airport 120 miles off the nose. Normal airspeed was getting too low to continue the flight and the airport was a practical landing destination for us. We notified ATC of the divert and a precautionary landing at the airport. They suggested closer airports; but the engine still made power and landing in our planned divert station allowed us to make a normal descent and accomplish all checklists without rushing. The company was also notified of the divert using the flight phone. The passengers were notified of the change in destination and situation. Descending through FL200 we started the APU so as to have a second generator operational in case we had to shutdown or lost the engine. We also reviewed the single engine approach and landing checklist since we had the time and to just be familiar in case we needed it. Vectors to the ILS were accepted and a normal approach and landing followed. The airport had one rescue vehicle in the touchdown zone (clear of runway safety area) and trucks outside of the firehouse for us though they were not requested. No oil filter bypass light ever came on (we thought it may be coming) and upon notifying maintenance safely on the ground they requested we check the engine chip detector in the tail compartment; no lights illuminated.

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Original NASA ASRS Text

Title: CE560 First Officer reports diverting when the number one engine oil pressure cannot be maintained below the upper limit. Uneventful landing with both engines running ensues. Post flight inspection does not readily reveal the cause of the high oil pressure.

Narrative: On climb out number one engine oil pressure was observed high; but within limits. As climb continued oil pressure exceeded normal limitations. High oil pressure checklist completed and power reduced on number one engine to keep oil pressure within limits. Notified ATC and stopped climb at FL360 because of reduced power; continued climb was not possible. Oil pressure continued to climb above normal operating limits; power reduced. At FL360 and .62 Mach we made the decision to divert to an airport 120 miles off the nose. Normal airspeed was getting too low to continue the flight and the airport was a practical landing destination for us. We notified ATC of the divert and a precautionary landing at the airport. They suggested closer airports; but the engine still made power and landing in our planned divert station allowed us to make a normal descent and accomplish all checklists without rushing. The Company was also notified of the divert using the flight phone. The passengers were notified of the change in destination and situation. Descending through FL200 we started the APU so as to have a second generator operational in case we had to shutdown or lost the engine. We also reviewed the single engine approach and landing checklist since we had the time and to just be familiar in case we needed it. Vectors to the ILS were accepted and a normal approach and landing followed. The airport had one rescue vehicle in the touchdown zone (clear of runway safety area) and trucks outside of the firehouse for us though they were not requested. No oil filter bypass light ever came on (we thought it may be coming) and upon notifying Maintenance safely on the ground they requested we check the engine chip detector in the tail compartment; no lights illuminated.

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.