B777 flight crew and Dispatcher reported failure of the SATCOM system and loss of engine oil quantity resulted in a diversion.
Synopsis
B777 flight crew and Dispatcher reported failure of the SATCOM system and loss of engine oil quantity resulted in a diversion.
Narrative
Aircraft X ZZZZ divert sequence of events: XA:16 block out; XA:32 takeoff; XD:38 oil quantity notification. Oil pressure deteriorated over 30 - 40 minutes. XE:38 approximate fuel jettison. XF:16 block in at ZZZZ.Captain's leg from ZZZZ1 to ZZZZ2. At about XD:38; the secondary engine display popped up on the MFD (Multi-function Flight Display). I first noticed that the right oil quantity was highlighted in a white box showing 3 while the left engine oil quantity showed 18. Oil temp and oil pressure were normal at this time. The crew discussed that this may be a sensor issue with no secondary indications and that we should call Maintenance Control. The crew attempted to make multiple satellite calls. None of the SATCOM calls would go through. Each time the display would read SAT-1 /2 FAIL: CONNECTION. We did not get any EICAS for SATVOICE LOST on any of the attempted SATCOM calls.While the crew monitored the secondary engine display indications; right oil quantity continued to drop to 0. About 5 minutes after secondary engine display right oil quantity displayed 0; right engine oil pressure started decreasing. First indication; was the right engine oil pressure was 57 psi; while left engine oil pressure was 69 psi. The crew continued to try SATCOM calls to Dispatch and Maintenance Control while they tried to troubleshoot SATCOM with no indication of a malfunction displayed in the EICAS. The crew considered making a phone patch to Dispatch; but the crew could not find HF coverage of this area in the FOM.The crew started discussing divert options in this area. At this point the aircraft was approaching ZZZZ from the southeast. We had just passed a few countries; both which were declined by the crew as good options for a divert. We discussed pressing across [a body of water] to reach a more suitable divert closer to our destination with better security outlook; but with the engine oil pressure decreasing; we felt it was not the best option. We discussed possibly holding over ZZZZ. The crew also identified the potential requirement to jettison gas to normal landing weight prior to a divert into ZZZZ. The crew opened the Loss of Oil Pressure Right Non-normal Checklist to review it in case we had to perform a precautionary shutdown. In an attempt to maintain the right engine oil pressure as long as possible; the Captain elected to exercise Captain's authority and disconnected the right autothrottle and slightly reduced the power to see if the right engine oil pressure would stabilize and stop decreasing. The right engine oil pressure continued to decrease over a period of approximately 30 minutes from 57 psi to 52 psi to 44 psi to 40 psi to 34 psi to 25 psi to 19 psi. Each time the oil pressure would decrease; then stabilize and increase slightly for a couple minutes; then it would decrease again.The crew directed the Jumpseat Loadmaster to the back of the airplane to visually inspect the engine nacelle for visual evidence of the leak. He was not able to visually confirm evidence of an engine oil leak on the right engine. The Captain transferred aircraft control to me while she troubleshot the SATCOM radios; looked for HF phone patch options; and conducted the radio relay with Aircraft Y. After the crew attempted several more SATCOM calls; the crew contacted Aircraft Y that was slightly ahead of us on a similar route to request a relay to Dispatch via their SATCOM. Aircraft Y relayed our situation of loss of engine oil quantity and decreasing engine oil pressure on the right engine; and intentions to likely divert into ZZZZ to Dispatch; and solicited Dispatch recommendations. We received a response back from Aircraft Y that Dispatch's recommendation was also a divert to ZZZZ. By this point; the aircraft was beginning to coast out over the [body of water]. The crew decided to turn back for a divert into ZZZZ. The Captain had to [advise ATC] to ZZZZ in order to break into very busy radio chatter in order to get ZZZZ Control's attention and receive priority handling.Once the crew turned back toward ZZZZ; ATC cleared them direct to ZZZ [VOR]. With the FO (First Officer) as the pilot flying and the Captain pilot monitoring and the right engine oil pressure in the yellow at 19 - 17 psi; the crew performed the Loss of Oil Pressure Right Checklist as a precautionary shutdown even though there was no EICAS warning. The crew completed the checklist and executed the VNAV Engine Out page and requested a drift-down descent to FL240. The crew also diverted the FMS to ZZZZ.The crew set up the aircraft to jettison fuel to the normal landing weight; approximately 23 - 25K; and received approval from ZZZZ to jettison fuel from ZZZ1 [VOR]. ATC then changed the approval to jettison fuel from ZZZ [VOR] at approximately FL220. The fuel dumping took about 5 - 6 minutes; and the crew completed the Fuel Jettison Checklist.The Captain requested vectors for the ILS XXC at ZZZZ; and we were told to expect that. ATC at ZZZZ responded that we would be given vectors for ILS XXL. The Captain set up the FMS; briefed the approach; and flaps 20 autoland for ILS XXL at ZZZZ. The Captain briefed via the QRH; including the non-normal landing data. While on vectors; the Captain [requested priority handling] and requested fire truck support on landing. The Captain took the controls back and flew the vectors for the ILS XXL approach. The crew received numerous heading changes and step-downs during vectors for the approach. The crew completed the Approach; and Before Landing Checklists while on vectors.The Captain executed an uneventful single-engine autoland to Runway XXL at ZZZZ. The wind was 280 at 9 kt. on landing. The Captain cleared the runway at high speed Taxiway 1. After the uneventful landing and roll-out; taxied to the assigned Gate XX. After the crew shut down the remaining engine at the gate and opened the crew door; chaos ensued with [people] and representatives asking numerous questions ranging from what happened and why we were there to what kind of cargo we were carrying. The Captain got on the phone with the Duty Officer to let the company know what had happened since we're unable to make contact via SATCOM; which still was not working on the ground. The Captain was giving the DO (Duty Officer) a situational report as well as determining our reporting requirements.Someone from the ground personnel requested that a crewmember come outside to look at the main gear. Upon arriving at the left main gear; the #5 main gear was smoking. I immediately cleared the area to the side of the gear and requested the authorities contact the fire trucks to respond. I directed that the Fire Department set up cooling fans on the smoking gear. As I went down to find the #5 brake was smoking; the EICAS for brake temperatures annunciated in the flight deck. The Captain sent a representative down to ensure everyone was clear of the hot brakes. The Captain came down; while on the phone with the DO; to check that aircraft was chocked so she could release the brakes. The Fire Department asked us if they could put water on the brakes to cool them. After consulting with Maintenance Control to confirm; we communicated that was not advisable. Two cooling fans were focused on the hot brakes; but the fuse plug melted on #5.The questions from the authorities continued with significant language barriers; i.e.; the meaning of corrosive and hazardous cargo; as well as requests for overfly permits; cargo airbills; etc. Calls continued to the DO; Dispatch; and Maintenance Control as we waited for the brakes to cool. Upon completion of answering most of the questions; the Captain powered down the airplane and we deplaned approximately 3 hours after landing. The crew went through Immigration; Customs; and out to the hotel. We met the Company Representative at the hotel. Crew debriefed after checking into the hotel.Cause: The malfunction was a mechanical failure; but both the Captain and I were fatigued due to trip revisions and swapping from night schedule to day schedule with two back-to-back min crew rest periods prior to the flight.Suggestions: The mechanical issue may or may not be preventable based upon what is determined to be the cause of the oil leak. The eventual outcome of a successful divert and single-engine landing was due to experienced pilots working together as team to bring the airplane in safely. Good crew coordination skills and training helped bring a successful result. Malfunctions like this without the ability to coordinate with Dispatch due to communication failure of the SATCOM require the teamwork of two experienced pilots to bring it to a successful conclusion.
Second reporter narrative
Aircraft right engine oil showing 0 and pressure was decreasing. Crew [advised ATC] but did not take priority. Dumped 25K of fuel... diverted to ZZZZ. I was advised by the crew that [they advised ATC] and dumped fuel only after landing when Captain called Maintenance Control first.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.