Date: 202103
Local time of day: 1801-2400
Location: ZZZZ.ARTCC, FO
Flight conditions: VMC
Light: Night
Aircraft: B747-400
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
ATC / advisory: Center ZZZZ
Aircraft component: Lubrication Oil
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Second reporter function: Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Maintenance
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Procedure

Narrative: I was sitting in the left jump seat. Less than an hour into the flight from ZZZZ to ZZZZ1; a status message alerted the CA (Captain) and FO (First Officer) to an Oil quantity of '4' on the number four engine. Another CA; sitting center seat; was direct by the PIC CA to call dispatch and begin discussing options. During this conversation with Dispatch and Maintenance the oil quantity continued to fall. By the end of the conversation the oil quantity was '2.' As there were no secondary indications; and the procedures call for continued operation of the engine; the crew; Dispatch; and Maintenance concurred that continuing to ZZZ1 was best. Shortly thereafter; the oil quantity indication read '0' but oil pressure and oil temps remained normal. At approximately XA:50; oil pressure began to fall on the number 4 engine. Dispatch and Maintenance were again consulted. As an engine shutdown was imminent; it was agreed by all that returning to ZZZZ was the best course of action. ATC was contacted and provided return routing. The crew reviewed all checklists and reviewed the emergency section of FOM. When oil pressure dropped into the 'red' at '10' the engine was shutdown IAW the QRH. ATC was notified; and the PIC landed uneventfully at ZZZZ. Overall; I believe the aircrew effectively utilized all resources and employed effective CRM during this inflight shutdown.


Second narrative: Takeoff and climbout were uneventful. Shortly after top of climb the secondary engine indications appeared on the lower EICAS. The #4 Engine Oil Quantity indicated around 5 quarts. I called the second Captain back to the flight deck. I had him Satcom Dispatch and Maintenance Control. I checked engine out performance and noted that an altitude change was not necessary. We discussed the issue and had Dispatch calculate 3 engine cruise to ZZZZ1. Several minutes later the Oil Pressure began to slowly drop. We updated Dispatch with the deteriorating indications. We contacted Dispatch and Maintenance control to update them as to this not being an indication error. We discussed proactively returning to ZZZZ verses waiting for an engine shutdown to steer our decisions. This time a Duty Pilot was brought into the conversation and it was agreed by all that returning to ZZZZ would be the best course of action. We asked Maintenance Control if we should consider shutting down the engine to avoid damage. Maintenance Control wanted us to wait until the QRH called for the shutdown. We turned back to ZZZZ at XA:50. At XB:24 we shut down the engine as required by the QRH due to Oil Pressure. We followed all guidance in the FCOM and FOM and notified ATC of the engine shutdown. The arrival; approach; and landing were uneventful. Ground Maintenance later told me that the O-ring was not installed when the starter was replaced causing the oil leak.I would suggest that Duty Pilots are included in all calls to Maintenance Control. They could easily be subject experts on simple MEL applications in line operations as well as help steer events such as Diversions. I feel as they are the liaison between flight operations; Dispatch; and Maintenance departments and they bind the working groups together. Without the Duty Pilots input; it feels like an uphill battle between departments where no department wants to be responsible for a decision. There is a lot of resistance from the mentioned departments until the Duty Pilot enters the conversation at which time everyone seems to concur when the Duty Pilot agrees with the crew.


Synopsis: B747-400 flight crew reported that decreasing engine oil quantity caused an inflight shut down followed by a diversion.