Date: 201908
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class B ZZZ
Aircraft component: Hydraulic Main System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Fatigue
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Aircraft

Narrative: I was fatigued from operational issues related to managing the hydraulic failure and emergency air return to ZZZ. My fatigue was also related to the all-night flight from ZZZ1 to ZZZ that morning with day sleep in the field layover hotel. I was too fatigued to accept duties associated with completing an additional flight to ZZZ1; especially with an unknown departure and arrival time. If the flight had somehow managed to depart in the next hour after our block in; I knew that I would still be too fatigued on arrival to safely respond to anything beyond a routine arrival.


Second narrative: In climb out from Runway XXR at ZZZ; a pilot announced over the Tower frequency that our right main landing gear was smoking.Tower restated the observation. I elected to extend the landing gear. Shortly after; another pilot stated it might be hydraulics. We acknowledged and were transferred to departure. Meanwhile no EICAS messages appeared; so I called for gear retraction after looking at the Hydraulic synoptic and requested the after takeoff checklist. Shortly after; EICAS Hydraulic related messages began appearing: the most prominent being: Hydraulic System C. I transferred control of the aircraft to the First Officer after a quick brief; notified Departure Control of our condition and [requested priority handling]; along with a request to hold and work through checklists.ATC acknowledged giving us vectors instead. The vectors complicated matters because they kept us transferring frequencies frequently while we were accomplishing checklist items. With a total loss of a system hydraulics and appropriate checklists completed; I notified Dispatch; [Maintenance Control]; spoke with the lead Flight Attendant and briefed the passenger. We coordinated preparation for landing but I deferred on the need for a brief to evacuate with the Flight Attendant.After consulting all pertinent data including non-normal landing distance data; and notes on secondary system flat/slat extension times; and unavailable components; a briefing for a long straight in final approach to Runway XXR was briefed and I flew the approach.The landing was uneventful; we had [crash fire rescue equipment] standing by along with a request for a tow vehicle. [Crash fire rescue equipment] communicated with us after I brought the aircraft to a stop on the runway stating: you are still losing hydraulics from the right main gear. Therefore; after checking brake temps I decided to accept the tow vehicle in lieu of a possible brake overheat/fire; especially after Maintenance arrived; requesting we shut down all hydraulics and the engines; (which we did after starting the APU) and the hydraulic fluid continued. We were towed eventually off the runway but it took a while because the first tow vehicle broke down.Meanwhile the Lead Flight Attendant called (I had been in contact since landing) and said a few passengers in the back were complaining about the smell. The aircraft was half empty so I had the Flight Attendant move said passengers and I turned off the Recirculating fans. The Flight Attendant called back and said the smell had dissipated.At the gate we disembarked the passengers; I met with Maintenance and called the [Chief Pilot].


Synopsis: First Officer reported fatigue from aircraft maintenance problems and did not think it was safe to fly.