Narrative:

Halfway through our flight over the mountains; we were alerted to an ECAM which read 'yellow hydraulic low pressure.' we followed the ECAM and noted yellow quantity was nearly empty. We notified dispatch and he came back with divert options. I further reviewed hydraulic irregulars and hydraulic system in the flight manual to clearly assess our situation. The ECAM isolated the yellow system and our loss of some spoilers and our yaw damper was our flight control issue. After assessing our divert options; we chose ZZZZ1 because of WX and familiarity on my part. Dispatch gave us a route and ATC cleared us after declaring an emergency. The captain alerted the crew and passenger of our plans and situation. We reviewed the runway performance and overweight landing checklist. Dispatch assisted us and ATC was clear and helpful. We started our descent to the field. As we slowed the aircraft had an unusual rhythmic shudder that felt like it was the yaw damper. We slowed early for the approach and was cleared for the VOR-DME to runway xx ZZZZ1 in VFR conditions. With limited ground spoilers; no reverse thrust on the #2 engine and alternate brakes inoperative; the captain set the aircraft down with a 200 FPM descent rate. The overnight landing was smooth and uneventful touching down at about the 1000 ft mark to turn off the runway at taxiway X. We then taxied to the ramp with tower to be met by our contract handlers and maintenance.

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Original NASA ASRS Text

Title: AN A320 FLT CREW LOST YELLOW HYD SYS IN CRUISE FLT. THEY COORDINATED WITH DISPATCH AND MAINT BEFORE DECIDING TO DECLARE AN EMERGENCY AND DIVERT TO THE NEAREST SUITABLE ARPT.

Narrative: HALFWAY THROUGH OUR FLT OVER THE MOUNTAINS; WE WERE ALERTED TO AN ECAM WHICH READ 'YELLOW HYD LOW PRESSURE.' WE FOLLOWED THE ECAM AND NOTED YELLOW QUANTITY WAS NEARLY EMPTY. WE NOTIFIED DISPATCH AND HE CAME BACK WITH DIVERT OPTIONS. I FURTHER REVIEWED HYD IRREGULARS AND HYD SYS IN THE FLT MANUAL TO CLEARLY ASSESS OUR SITUATION. THE ECAM ISOLATED THE YELLOW SYS AND OUR LOSS OF SOME SPOILERS AND OUR YAW DAMPER WAS OUR FLT CTL ISSUE. AFTER ASSESSING OUR DIVERT OPTIONS; WE CHOSE ZZZZ1 BECAUSE OF WX AND FAMILIARITY ON MY PART. DISPATCH GAVE US A RTE AND ATC CLRED US AFTER DECLARING AN EMER. THE CAPT ALERTED THE CREW AND PAX OF OUR PLANS AND SITUATION. WE REVIEWED THE RWY PERFORMANCE AND OVERWT LNDG CHKLIST. DISPATCH ASSISTED US AND ATC WAS CLEAR AND HELPFUL. WE STARTED OUR DSCNT TO THE FIELD. AS WE SLOWED THE ACFT HAD AN UNUSUAL RHYTHMIC SHUDDER THAT FELT LIKE IT WAS THE YAW DAMPER. WE SLOWED EARLY FOR THE APCH AND WAS CLRED FOR THE VOR-DME TO RWY XX ZZZZ1 IN VFR CONDITIONS. WITH LIMITED GND SPOILERS; NO REVERSE THRUST ON THE #2 ENG AND ALTERNATE BRAKES INOP; THE CAPT SET THE ACFT DOWN WITH A 200 FPM DSCNT RATE. THE OVERNIGHT LNDG WAS SMOOTH AND UNEVENTFUL TOUCHING DOWN AT ABOUT THE 1000 FT MARK TO TURN OFF THE RWY AT TXWY X. WE THEN TAXIED TO THE RAMP WITH TWR TO BE MET BY OUR CONTRACT HANDLERS AND MAINT.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.