Date: 201907
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Dusk
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Hydraulic Syst Reservoir Tank
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain; Instructor
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Communication Breakdown; Troubleshooting
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed As Precaution; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: OE (Operational Experience) Instructor PM (Pilot Monitoring) in level in cruise at FL370. Student was PF (Pilot Flying). Noticed Center Hydraulic System QTY light come on overhead and associated EICAS. (Approximately 250 nm North of ZZZ). Checked EICAS and saw CTR HYD fluid at .47 and dropping very slowly. Notified [Operations] and ATC of possible CTR HYD system failure and divert. Hydraulic fluid QTY slowly reduced but we didn't have system failure (CTR HYD Sys Press light) until within 20nm of ZZZ. We [advised ATC] and asked for delaying vectors while we worked the issue and checklist. While doing the Center HYD Sys pressure checklist and configuring the flaps; we also got a Trailing Edge Flap disagree msg on EICAS. After going through that checklist I attempted to get a hold of an [Engineer] in ZZZ1 just to confirm the proper flap procedure that the checklist was telling us to do. It took a VERY long time to get a [Engineer]. He tried but wasn't really helpful and I don't think he was a [Engineer]. We continued the checklist and proceeded to land at that point because fuel was starting to become an issue. We landed with Flaps 1 (ILS XXR ZZZ) and ended up having nose wheel steering. We cleared the runway. Taxi to ramp was uneventful. Maintenance met us on ramp and said that we did indeed have a leak. Center HYD Fluid on EICAS read .10 at engine shutdown. The [event] was complicated by the fact that we had a flap issue while working the Hydraulic failure. I was sorely disappointed that it took at least 15 minutes or more to get a hold of what I thought was going to be a [Engineer] and didn't get one. I wanted to be 100% certain that our actions were correct and I wanted [an Engineer] to back us up on that. Never happened. Thankfully I had a very sharp student and jump seater as well that provided a lot of guidance and support so that we operated and landed safely without incident.


Second narrative: During cruise to ZZZ; we received a center HYD QTY low EICAS and light. Actual quantity was low and decreasing slowly. We did not have a loss of system pressure until 20nm from ZZZ at which point we [advised ATC] and got extended vectors to run the checklist and configure via alternate means. During the alternate flap configuration we got a TE (Trailing Edge) flap disagree trying to move from flaps 1 to flaps 5. Had to pause HYD pressure checklist to run flap disagree checklist. We attempted to reach a [Engineer] on SATCOM for some backup but there was a delay in getting a hold of one and comms were weak. Luckily we had a jump seater who followed us through the procedure. We landed flaps 1 and were lucky to still have nose wheel steering at final configuration. Overall the crew worked well together to resolve multiple [issues]. My biggest concern was how easy it was to get confused when running two simultaneous non-normal checklist at the same time in which many steps were similar or already accomplished on the other checklist. Landing was without incident.


Synopsis: B767 flight crew reported multiple problems with the aircraft hydraulic system; and being unable to reach a company engineer for support.