Date: 201307
Local time of day: 0001-0600
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Hydraulic System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface; Communication Breakdown; Confusion
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency; General Maintenance Action
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: In cruise; we got an ECAM for Green System Hydraulic Reservoir Low Quantity. Confirmed on the system page that green system quantity was almost at 0. I ran the ECAM while the First Officer handled the flying and the radios. After shutting off the PTU and the Green Eng Pump per the procedure; I reviewed the status with the First Officer. We decided to declare an emergency; and it became clear that continuing to our destination would not be the safest course of action. I had difficulty communicating with Dispatch regarding our plan of action; so we made the decision to head towards ZZZ as a diversion to the nearest suitable airport was not required. I then continued to work the problem with the ECAM and the QRH; while informing the flight attendants of our plan of action and time remaining. After reviewing the ECAM and the QRH; I came across a discrepancy which I wanted to resolve with Maintenance Control before landing. In the QRH; it showed that the status page would show APPR PROC HYD LO PR - L/G GRVTY EXTN. This made sense to me. The ECAM; however; said APPR PROC HYD LO PR - GREEN ENG PUMP ON; and only to use gravity extend if that didn't work. I was [now] able to contact Dispatch and Maintenance Control via radio who confirmed that we should follow the QRH procedure and NOT the ECAM. I did this and accomplished the L/G GRVTY EXTN procedure. ATC had been notified that we would need to be towed off the runway. On final; we reviewed all the appropriate after landing procedures; calculated that we had plenty of performance to land and; with no nosewheel steering available; told the First Officer to stop straight ahead. He accomplished a normal landing; and we stopped on the runway with minimal issues. We stopped; told the flight attendants and passengers to stay seated; and that we would be towed off shortly. The ground staff brought a Supertug; and asked us to restore hydraulics to all 3 systems via PTU and Blue System override. We did so after discussing the ramifications; but the gear doors would not come up. We were then asked to stow the Manual Extension handle; but I declined; as our QRH specifically says not to when on the ground. The ground crew said they couldn't tow with the gear doors open; but I wasn't sure that stowing the handle would allow them to raise the gear doors. I called Maintenance Control on the phone and they concurred NOT to stow the handle. Eventually; they put the aircraft on the Supertug and towed us slowly; carefully and uneventfully to the gate.


Second narrative: Approximately 280 miles south of ZZZ at 34;000; we experienced an almost total loss of Green system hyd fluid due to failure of the green system engine driven pump.


Synopsis: Following the loss of the Green Hydraulic System the flight crew of an A319 declared an emergency and diverted to an enroute station where they landed safely and were towed to a gate.