Date: 201808
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Hydraulic Main System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I was the First Officer operating Aircraft X. We were in an Airbus A320.The flight departed ZZZ at XY32 and climbed to FL330. At approximately XY55 we received the ECAM caution messages; HYD Y ENG PUMP LO PR; and HYD Y RSVR LO LVL. A review of the hydraulic page revealed zero pressure in the Yellow hydraulic system and a negligible quantity. We ran the ECAM items and then reviewed the QRH. We concluded that the ECAM checklist was appropriate; disabling the number 2 engine hydraulic pump and the PTU. We also concluded that the appropriate QRH checklist was for HYD Y RSVR LO LVL and reviewed it fully.The two items of concern on the checklist was the possibility that the spoilers 2 and 4 would float without hydraulic pressure; and that the parking brake accumulator would not have pressure for parking. We had a deadheading pilot check the spoilers; and he stated they appeared to be down - the flight characteristics of the airplane supported this observation. The brake accumulator did not deplete quickly; but on our arrival; there was insufficient pressure remaining to adequately set the parking brake.We discussed the option of diverting; and then contacted dispatch and maintenance control. We concluded that diverting to ZZZ or ZZZ1 was a proper plan of action. At this point we were closer to ZZZ; but factoring in the winds; ZZZ [over] ZZZ1 were of similar time. We also re-considered diverting to a closer airport. With the yellow system failed and the spoilers closed; there was no degradation of the immediate safety of the flight. Diverting would have resulted in an overweight landing; or holding for an extended period of time. We deemed that a higher risk than continuing to ZZZ1.We descended to a lower altitude to increase fuel burn to assure the landing in ZZZ1 would not be overweight. I calculated the fuel load that would result in maximum landing weight and we referenced this prior to landing.Approximately 200 miles from ZZZ1; we [notified ATC]. The flight was operating normally and there was no safety loss while en route. Our declaration was to provide us with emergency equipment on the field; runway choice; and greater leeway with ATC considering the slower flap speed; and our inability to fully extend the speed brakes.I briefed the captain to expect a substantial yaw with only one reverser deployed. We concluded the best course of action would be to land with the flaps in the Full position; auto brakes in Low; and idle reverse with the No. 1 engine.The approach and landing were uneventful; and we were at approximately 141;000 pounds on touchdown. Fire and Rescue circled the aircraft and reported no apparent problems. Steering and braking were normal; and other than the loss of the Yellow hydraulic system and the accumulator pressure (and thus the parking brake); there were no other system or operational degradations. I made a PA announcement while the airplane was stationary to inform the passengers of the actions of the Fire and Rescue crew; and that we would be proceeding to the gate after inspection.We taxied to the gate; and when I contacted ramp tower; I asked them to remind the ground crew that the aircraft would have to be chocked prior to engine shutdown as there was no parking brake available - we had contacted the station prior with this information.Once the aircraft was at the gate and chocked; the engines were shutdown. Brake temperatures peaked around 450 degrees.Station representatives met us at the gate; and we discussed the matter with maintenance personnel as well. Both the captain and I were debriefed by representatives from the ZZZ1. Reviewing our actions; I would conclude that given the information that we had been provided; that the decision making process was sound and that no better option existed. The smooth air en route; the long runways at ZZZ1; and the time to prepare and plan was a superior course of action versus an immediate diversion and an overweight landing; considering the only failure and risk was the loss of the Yellow hydraulic system.


Second narrative: We reached our initial cruise altitude of FL330 without incident. I pulled up the synopsis page for all aircraft systems and all appeared normal. After several minutes; we received a HYD Y RSVR LO LVL ecam. The reservoir was completely depleted. I took control of the aircraft and radios and had the FO run the ECAM and QRH. The ECAM called for turning off the Y ENG pump. I then called dispatch and had Maintenance patched into the call as well to go over the mechanical. With the yellow system inop; we were left with partial spoilers and only 1 thrust reverser. With that in mind; I did not want to continue to [destination] with a short runway. After conferring with dispatch; it was decided that ZZZ1 was the best solution for a divert as we had to burn off roughly 6200lbs of fuel to get below landing weight. We continued the flight and landed uneventfully and taxied normally to the gate.


Synopsis: An A320 flight crew reported that ECAM displayed a 'HYD Y RSVR LO LVL'; and the reservoir was completely empty.