Date: 201503
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: EMB ERJ 145 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Powerplant Lubrication System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Inflight Shutdown
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: Our flight was delayed due to inclement weather affecting the area. At the time; we were experiencing heavy snow conditions with low visibility. Once we arrived at the aircraft; company maintenance personnel was on-board performing an MEL for GEN 1 Bearing. It was the only maintenance item being performed. All else was routine with passengers eventually being boarded and deicing/anti-icing being performed on the aircraft. Once the flight was underway and we were level at our filed cruise altitude of FL350; approximately 35 minutes into the flight I noticed a considerable drop on oil pressure on Engine #1. The captain noticed the same indication and promptly checked the oil quantity indication on his MFD and it indicated approximately 3 quarts of oil for Engine #1. All other engine indications were in normal parameters.To prevent possible damage to the engine; we reduce it to Idle Thrust. We identified and verified Engine #1 thrust lever and I brought it down to IDLE. The Captain and I agreed to perform the QRH for the Precautionary Engine Shutdown. The Captain notified Center we had shut down an engine with the intention to divert. I had started a descent to preserve airspeed. Company was notified via ACARS of the situation with the Flight Attendant briefed by the Captain. The Captain also made a subsequent PA to the passengers.It was very busy in the cockpit; with the workload being well-balanced. I elected to continue the use of the autopilot as we prepared for the single-engine landing. We ran all appropriate checklists; As we got close to being vectored onto the final approach course for the ILS; the Captain was busy getting the single-engine landing data. I suggested delaying vectors if needed but he was comfortable with the time available. This proved to be fine as he inputted the data. We were prepared for the landing with me Pilot Flying.The single-engine approach and landing went smoothly. At no point were there any adverse control effects and the fairly clear skies and calm wind worked well for us. The landing was smooth and uneventful with ARFF equipment standing by. Once clear of the active runway we stopped and requested to have ARFF take a look at the aircraft; in particular Engine #1 and the surrounding area. Once all checked OK. We proceeded to the gate under our own power and deplaned the passengers. Contract maintenance was there almost immediately to investigate the cause of the failure.




Synopsis: EMB-145 First Officer experiences low oil quantity and low oil pressure at FL350 and the engine is shut down as a precaution. Flight diverts to a suitable airport and lands uneventfully. Maintenance had performed an MEL procedure on the number one generator prior to departure; which may have been the source of the leak.