Date: 201902
Local time of day: 1801-2400
Location: ZZZZ.Airport, FO
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Hydraulic System Lines; Connectors; Fittings
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Commercial
Anomaly: Aircraft Equipment Problem Critical; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Enroute at FL380 we had a master caution light and a low pressure light on the ENG 2 B system engine driven hydraulic pump. We flipped the switch to the off position as per the QRH; noted that the B system quantity and pressure appeared normal; and pressed on. During descent we noticed the quantity had rapidly dropped to zero so we pulled out the loss of system B QRH. I handed the jet to the First Officer as I went through the procedure. He wisely left the system A autopilot engaged as we worked together to run the QRH and prepare for landing. We pulled up the abnormal landing distance factors since we had some time; but we both knew that XXL would be more than adequate. We [advised] ATC and asked for a 20 mile final to give us time to configure. We both agreed on downwind that we were ahead of the game and were just waiting to turn base to start configuring; so I took over as flying pilot as it was my leg initially.On base; I slowed to clean maneuver as the First Officer started extending the flaps. On about an 18 mile final; we had the gear down and the flaps extended to 15; which was the final flap setting in this scenario. However; the flaps 15 REF speed +5 was deep into the yellow arc on the PFD airspeed tape. The stick shaker activation speed (Red) was showing right at the VREF speed. We noticed that the leading edge device indicator was still amber. We looked up at the slat indicator panel and noticed that slat 3 and 6; or one in the same spot on each wing; were showing amber while the other slats were showing full extend. A quick look at the wing told us that they all appeared to be deployed evenly. We tried to tap the flap down switch a hair to see if the light would go out but it did not. We chalked it up to this being an SFP (Short Field Performance) aircraft and considered it an erroneous indication. I used the flap 5 maneuver speed as a final REF speed; which was only 5-10 knots above the flap 15 speed just as an added precaution; though that speed was still within the indicated yellow arc. We advised ATC that we would be able to taxi to the gate after landing as we had normal steering and alternate brakes. They advised us that a truck would follow us down the runway after we landed to observe.We landed and cleared the runway and expected to taxi to our gate at the south satellite as we had to clear customs. Of course; our gate was occupied and we were told to park on [a] taxi lane and wait for catering to finish with the jet on our gate. As we sat parked; an Operations vehicle stated that fluid was leaking out of our right wing. We turned off the right pack and #2 bleed just as a precaution in case some fluid was able to be ingested through the ram air doors or into the engine. Initially; I had briefed that we keep both engines running all the way to the gate since we had a non-normal condition. We decided that shutting down number 2 at this point would not adversely affect our ability to taxi so we shut it down. It took about 30 minutes for a gate to become available. We were advised that the leaking was slowing down as the supply of system B was totally exhausted.At some point during our wait for a gate; we noticed that the leading edge indicators were now showing full extend; with a green light on the forward panel. We had Operations advise the ramp agents to use caution as we were leaking Skydrol. The port did a great job of staying mostly out of sight and no passengers said anything to us; so they were likely unaware. The flight attendants knew we had a pump fail at cruise; but we didn't see the need to advise them that we had lost an entire system as by the time we would have been able to do that we were on downwind and well below 10;000 feet. Neither of us anticipated anything other [than] that a normal landing and deplaning and that is exactly what occurred.




Synopsis: Air carrier Captain reported the loss of a hydraulic system and a slat indication issue.