Narrative:

During cruise; approximately 1 hour into flight; doing routine checks; discovered green hydraulic system indicating almost '0' quantity; normal 3000 psi pressure; no ECAM warnings; all system operations normal. Contacted maintenance and was advised to 'follow QRH procedures.' no QRH procedures were found for the above conditions; continued to monitor green hydraulic quantity throughout flight. No changes observed. Concluded that ECAM indication for green hydraulic quantity was most likely inaccurate -- failed. As a precaution; we planned on and briefed our plan of action for a complete green hydraulic failure; including advising the flight attendants. On approach into ZZZ; no changes in green hydraulic quantity or ECAM failures noted; even during flap extension; and we expected a normal landing. When gear was selected down at 1500 ft AGL; green hydraulic quantity low level and green hydraulic pressure low warnings triggered on ECAM; followed ECAM procedures. Since we had prebriefed for a possible hydraulic failure we continued approach; notified tower of oursituation; changed runways to runway xxl (longer runway) and advised flight attendants. Landing was uneventful and we were able to clear the runway on a high speed taxiway. Company was notified that we would need to be towed to the gate (no steering) and kept passenger updated on our condition. 30 mins later; we arrived at the gate.

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Original NASA ASRS Text

Title: A320 GREEN SYSTEM HYDRAULIC FAILURE IS PREDICTED BY LOW QUANTITY INDICATION. NO ECAM WARNING UNTIL GEAR IS EXTENDED FOR LNDG. ADVANCE PREPARATION LIMITED THE IMPACT ON A TIMELY ARRIVAL.

Narrative: DURING CRUISE; APPROX 1 HR INTO FLT; DOING ROUTINE CHKS; DISCOVERED GREEN HYD SYS INDICATING ALMOST '0' QUANTITY; NORMAL 3000 PSI PRESSURE; NO ECAM WARNINGS; ALL SYS OPS NORMAL. CONTACTED MAINT AND WAS ADVISED TO 'FOLLOW QRH PROCS.' NO QRH PROCS WERE FOUND FOR THE ABOVE CONDITIONS; CONTINUED TO MONITOR GREEN HYD QUANTITY THROUGHOUT FLT. NO CHANGES OBSERVED. CONCLUDED THAT ECAM INDICATION FOR GREEN HYD QUANTITY WAS MOST LIKELY INACCURATE -- FAILED. AS A PRECAUTION; WE PLANNED ON AND BRIEFED OUR PLAN OF ACTION FOR A COMPLETE GREEN HYD FAILURE; INCLUDING ADVISING THE FLT ATTENDANTS. ON APCH INTO ZZZ; NO CHANGES IN GREEN HYD QUANTITY OR ECAM FAILURES NOTED; EVEN DURING FLAP EXTENSION; AND WE EXPECTED A NORMAL LNDG. WHEN GEAR WAS SELECTED DOWN AT 1500 FT AGL; GREEN HYD QUANTITY LOW LEVEL AND GREEN HYD PRESSURE LOW WARNINGS TRIGGERED ON ECAM; FOLLOWED ECAM PROCS. SINCE WE HAD PREBRIEFED FOR A POSSIBLE HYD FAILURE WE CONTINUED APCH; NOTIFIED TWR OF OURSITUATION; CHANGED RWYS TO RWY XXL (LONGER RWY) AND ADVISED FLT ATTENDANTS. LNDG WAS UNEVENTFUL AND WE WERE ABLE TO CLR THE RWY ON A HIGH SPD TXWY. COMPANY WAS NOTIFIED THAT WE WOULD NEED TO BE TOWED TO THE GATE (NO STEERING) AND KEPT PAX UPDATED ON OUR CONDITION. 30 MINS LATER; WE ARRIVED AT THE GATE.

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.