Date: 201407
Local time of day: 0601-1200
Location: ZZZ.TRACON, US
Flight conditions: VMC
Light: Daylight
Aircraft: A319
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Landing; Descent
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ; Tower ZZZ
Aircraft component: Hydraulic Main System
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Confusion; Situational Awareness; Troubleshooting
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action; Flight Crew Landed in Emergency Condition; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft; Procedure
Primary problem: Aircraft

Narrative: On arrival at 10;000 feet we got a Yellow System Low pressure ECAM.  We lost all quantity.  I flew as the First Officer ran the ECAM and checklist references.  We determined that we had lost Yellow Hydraulic System; and thus the Number 2 Reverser.  With this in mind; we decided that [a nearby airport with] its long runways would be a better option than our filed destination and its short runways.  We declared an emergency with ATC and got vectors.  We configured early for resultant slower flap movement; and landed on 19.  The original plan was to taxi clear of XX and have emergency crews look us over. On landing we got an odd vibration from what felt like the right landing gear. We opted to stop straight ahead on the runway. Emergency crews inspected our aircraft and determined there was fluid on the right side of the aircraft and near the gear. There was no evidence of damage or potential for fire; and no cockpit indications of any need to stay on the runway and deplane so to more quickly get the passengers off the aircraft (rather than bring a transport vehicle out to aircraft); we opted to taxi back to a gate and deplane the passengers there.  All went uneventfully.  Only two items of note; we were never given a frequency for the emergency crews; so we had to initially use hand signals.  We could hear them on Tower frequency; but that was busy and not practical to talk on.  We asked Tower and they gave us a frequency that simplified the inspection process dramatically.  Also; there was a little bit of confusion between the emergency crews and my Company.  Because of the hydraulic fluid coming from aircraft; they wanted to get us to a remote pad and limit the fluid left on frequently used gate ramp.  The Company evidently insisted that we go to a gate; so we had to change plans twice.


Second narrative: [Report narrative contained no additional information.]


Synopsis: An A319 Yellow Hydraulic System ECAM alerted low quantity during descent so the crew completed the ECAM actions; declared an emergency and diverted to a nearby airport with long runways. After landing; initial Emergency Crew communications was difficult.