Date: 201707
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Lubrication Oil
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Other / Unknown
Anomaly: Aircraft Equipment Problem Critical
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: This was an ETOPS Enroute Verification Flight due to #1 Engine Change. During preflight I called Dispatch who connected me to Maintenance Control. Maintenance Control verified this was the first flight for this engine and we were to monitor it and send in the code if all went well. Preflight; pushback; start up and taxi were all normal. I informed our jumpseat rider that this was the first flight for the engine and that we would power up for takeoff and delay just a bit to make sure the engines were spooled up and operating. We did just that. We departed and flew the Departure with nothing out of the ordinary. Climbing through FL250 we received an ENG OIL PRESS L EICAS on the #1 Engine. The FO observed the oil pressure somewhere between 50-70 PSI. We also saw the EGT had reached 675C. We ran the checklist and shut down the engine. We advised Center; asked for lower altitude and a vector back. We ran the checklist. We ran the Overweight Landing checklist as we were slightly overweight. We were going to land approximately 10;000 lbs overweight. I deemed it safer to not delay the landing.  We checked the fuel imbalance and it was negligible.We got vectors and were cleared for the ILS. We made sure tower was aware of our situation and the rescue vehicles were standing by. We landed uneventfully and exited on Q. We taxied to gate and talked to the rescue vehicles. They said nothing appeared to be on fire or smoking but that it did appear we had some 'scorching' on our wing. We taxied to the gate and deplaned through the jetway. Our jumpseater was a 757 Captain who had been on the 777. He was a valuable resource to help in communication. I would also like to point out my FO was extremely professional and performed his duties as the pilot monitoring quickly and efficiently. I was grateful for the whole crew.


Second narrative: I was scheduled to deadhead and the flight was full. I requested and was issued a cockpit jumpseat. I am not qualified on the 777 but am quite familiar as I flew it for many years as a copilot. The captain gave me the jumpseat briefing and mentioned the left engine was replaced and this was the first flight since the replacement. Taxi and departure was normal. Climbing through about FL270; the left engine oil pressure EICAS illuminated and the oil pressure was fluctuating well below normal. The Captain; as the pilot flying; delegated the FO to run the checklist while he flew the aircraft and handled ATC. The checklist had them shut down the left engine and we coordinated a return. I worked with the crew to help reduce the workload and help with overall checklist completion and crew coordination. I helped communication with the flight attendants and dispatch. After all checklists were complete and diversion guide reviewed; we discussed as a crew; all of our options and that everything was completed. The return on the remaining engine was uneventful. Fire and Rescue saw no external damage and they followed us to the gate. We debriefed as a crew and then discussed the events with maintenance and the Chief Pilot. The CRM throughout the entire event; was outstanding and no errors were detected.


Synopsis: B777 flight crew reported receiving an aircraft after an engine change. Climbing through FL250; engine oil pressure began to drop and the engine was shut down. The flight returned to the departure airport.