DA20-C1 Eclipse
Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 10; Flight Crew Total 10000; Flight Crew Type 20
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Aircraft
During climb; engine began to run rough. Immediate level off. Engine roughness disappeared; engine ran normally. Continued flight. While adjusting mixture control; observed oil pressure begin to drop rapidly from approximately 55-60 PSI to approximately 20 PSI; then pressure returned to 55-60 PSI. Decided to proceed direct [to an alternate]. Approximately 8 miles [out] I tuned the communication transceiver to tower frequency and realized there were other aircraft operating in the traffic pattern. Requested priority for landing due to oil pressure issue. Tower controller gave immediate clearance as requested. As the approach to the airport continued; observed oil pressure drop from 55-60 PSI to approximately 40 PSI twice more. Landing was uneventful. Tower had; on their own initiative; called on-field Crash-Fire-Rescue and advised them of our situation. They were standing by near the touchdown point. Later; maintenance inspected the aircraft and the engine and did not observe any deficiencies.
DA-20 flight instructor reported diverting to an alternate after observing a drop in oil pressure.