Date: 202107
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Light: Daylight
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Hydraulic Main System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Overcame Equipment Problem; General Maintenance Action; General Flight Cancelled / Delayed
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Flight planning; preflight; ground operations; and takeoff were accomplished per SOP and were uneventful. Captain was pilot flying. Passing 18000 STD; altimeter was selected and AP 1 was selected. At XA:17; we got a master caution light; with HYD G RSVR LO LVL; HYD G ENG 1 PUMP LO PR; and HYD G SYS LO PR displayed on the upper ECAM. After confirming no Green Hydraulic QTY; I asked the FO (First Officer) to request to stop climb and return to field. Captain continued to fly and handle radios. FO accomplished the ECAM procedures; turning off the PTU and Green Eng 1 Pump. QRH was referenced after ECAMs completed; screens normal.We requested priority handling with ATC. Advised Dispatch through ACARS that we had lost all Green Hydraulic QTY; were returning to ZZZ; and would require a tow off runway due to loss of nosewheel steering. Purser was advised of the malfunction; that we were returning to field in 20 minutes; and a cabin prep was not required. A visual approach to XXL was briefed after runway assignment and the descent checklist was accomplished. Aircraft was configured early due to slow flaps/slats and alternate gravity gear extension. Approach and landing were accomplished per SOP and were uneventful. Aircraft was stopped straight ahead on centerline. Engines shut down with timing after starting APU. Aircraft was inspected by Fire Response Team; confirming gear doors down and fluid [was] leaking from under plane behind gear. Super tug arrived and towed us clear of runway to Gate XXX.


Second narrative: On climbout passing approximately 21;000 feet; we got an ECAM indicating loss of the green system; LO G Press; and another green system ECAM but I cannot recall it now. We ran the ECAM action items which had us turn off the PTU and Eng 1 G pump. As soon as the ECAM action items were complete; we communicated with ATC; advising them we needed to stop our climb; and requested priority handling and requested a return to ZZZ. The CA (Captain) and I split up the flying and comm duties; he advised the FA's (Flight Attendant) of our situation; and sent a message to Dispatch. I talked to ATC and flew the aircraft for a brief time while he handled the message to Dispatch.We got the expanded checklist and discussed the effects of [a] loss of the green system in terms of manual cranking of the gear and needing to stop on the runway due to loss of steering; which the CA sent an ACARs to the station to start working on a tow for us to minimize us sitting on the runway. I also advised ATC to let ZZZ know we would be a full-stop on the runway and would need to be towed. We were given priority handling back to ZZZ and we briefed the approach and threats of a go-around since the gear could not be retracted once it was hand-cranked down. The CA flew the approach XXL and the landing and stopping at the end of the runway was uneventful. We dropped the landing gear pins to the tug team and got towed back to the gate. We debriefed once we were off the aircraft and the passengers disembarked. The CA was cool; calm; and collected and flew a textbook approach. We worked well together as a team; I can't think of much that we could have done to improve on how the situation was handled.


Synopsis: First Officer reported loss of all green hydraulic system fluid caused an Air Turn Back and precautionary landing.