Date: 201910
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class B ZZZ
Aircraft component: Oil Pressure Indication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: The incident happened just prior to descent; about 20 minutes to ZZZ on our way back from ZZZ1. We flew the plane to ZZZ1 earlier that morning and it was the first flight of the day for this particular plane. When arriving to the plane in ZZZ we discovered the plane had an R ENG OIL PRESS Master Warning message on takeoff the day before which resulted in the crew shutting the engine down in flight and making an emergency landing back in ZZZ. Line Maintenance worked on the engine overnight and determined the engine lost 8 quarts of oil and after testing; replaced a seal in/on/near the engine driven oil pump. The plane was returned to service and we were the first crew to fly it since that incident the following day. The flight to ZZZ was uneventful. As stated previously; about 20 minutes to ZZZ on our way back from ZZZ1; we received an R ENG OIL PRESS Master Warning message accompanied with a triple chime. The message disappeared and reappeared roughly 10 times. During this time the Captain and I watched the oil pressure gauge for our right engine erratically jump between roughly 25-45PSI (normal PSI is around 65-70PSI and the warning message is triggered at 25PSI). Both the Captain and I noted that no other engine indications for our right engine were abnormal. Our Oil Temperature; Fuel Flow; N1; N2; and [CRJ] gauges were all showing normal indications and matched the indications of the left engine. Initially; as we watched the message continuously disappear; along with all other indications appearing normal we attributed the message to being a faulty sensor and made the decision to keep the engine running. At the time of the message; I was Pilot Monitoring and after the message went off a half dozen times; the Captain transferred the controls to me. The Captain sent an ACARS message to Maintenance; reviewed the Maintenance actions in the maintenance log for this exact issue that occurred the day before; as well as referenced the QRH. By the time we reviewed each of those the message had persisted and while it was still erratic; the PSI range was now between 20-30 PSI. After some discussion between the two of us; it was at this time we now believed it was no longer a faulty sensor causing the message. We made the decision to [Request Priority Handling] and follow the QRH which walks through shutting the engine down followed by a single engine landing. I continued to fly and communicate the emergency with ATC while the Captain followed the direction of the QRH. I set the plane up for direct ZZZ and requested the longest open runway in use. We did not entertain the idea of diverting as we were about 15 minutes from ZZZ at this point and it takes roughly 10 minutes to complete the QRH for the ENG OIL PRESS Warning Message. When the Captain completed the QRH he made calls to the Flight Attendant; the passengers and Dispatch in ZZZ. When he finished the QRH and his PA's; we were about 15 mile final and I transferred the controls back to him; assuming the role of Pilot Monitoring. The approach; landing; and taxi into the gate were all uneventful.At the time of writing this I have not been notified of what the official cause of the R ENG OIL PRESS Warning Message was and the plane has been repositioned to a maintenance base. Line Maintenance at ZZZ added oil to the right engine when we arrived at the gate and the passengers were off the plane. They said we had burned 7 quarts of oil in the right engine. They said they would need to do additional testing to determine exactly where the oil was hemorrhaging but the engine driven pump was suspected as it was determining cause of the similar situation the previous day.




Synopsis: CRJ-200 First Officer reported loss of oil pressure caused an inflight shutdown and an emergency landing.