Narrative:

During climb out, we noticed a system hydraulic quantity at approximately 1.3 gals decreasing. We contacted our maintenance coordinator as the quantity continued to decrease toward zero. Both the hydraulic 'a' and 'B' pressure indicators started fluctuating. The captain determined a total a/B system failure was imminent and mentioned this to maintenance coordinator. Maintenance suggested turning off b-pumps to possibly salvage hydraulic fluid. This was accomplished, an emergency was declared, and checklists for loss of a/B system (manual reversion) while returning back to the departure field. All checklists were completed and an uneventful landing, straight ahead stop on runway, and tug back to gate were accomplished. Upon inspection, local maintenance found 'a' system was the culprit while 'B' system was still operational. Callback conversation with reporter revealed the following information: reporter stated that there was not too much difference in flying the aircraft even though the flight controls went to manual reversion. It took a little more than normal control force to move the controls. Manual gear extension was simple enough that they had ample time to think about their problems. The 'a' system had failed but, the lower capacity 'B' system worked well. They had to be towed off of the runway upon landing as they lost their nosewheel steering with the loss of the 'a' hydraulic system.

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Original NASA ASRS Text

Title: A B737-200 HAS ONE OF ITS HYD SYS FAIL IN ZJX AIRSPACE. FLC DECLARES AN EMER AND RETURNS TO DEP ARPT.

Narrative: DURING CLBOUT, WE NOTICED A SYS HYD QUANTITY AT APPROX 1.3 GALS DECREASING. WE CONTACTED OUR MAINT COORDINATOR AS THE QUANTITY CONTINUED TO DECREASE TOWARD ZERO. BOTH THE HYD 'A' AND 'B' PRESSURE INDICATORS STARTED FLUCTUATING. THE CAPT DETERMINED A TOTAL A/B SYS FAILURE WAS IMMINENT AND MENTIONED THIS TO MAINT COORDINATOR. MAINT SUGGESTED TURNING OFF B-PUMPS TO POSSIBLY SALVAGE HYD FLUID. THIS WAS ACCOMPLISHED, AN EMER WAS DECLARED, AND CHKLISTS FOR LOSS OF A/B SYS (MANUAL REVERSION) WHILE RETURNING BACK TO THE DEP FIELD. ALL CHKLISTS WERE COMPLETED AND AN UNEVENTFUL LNDG, STRAIGHT AHEAD STOP ON RWY, AND TUG BACK TO GATE WERE ACCOMPLISHED. UPON INSPECTION, LCL MAINT FOUND 'A' SYS WAS THE CULPRIT WHILE 'B' SYS WAS STILL OPERATIONAL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THERE WAS NOT TOO MUCH DIFFERENCE IN FLYING THE ACFT EVEN THOUGH THE FLT CTLS WENT TO MANUAL REVERSION. IT TOOK A LITTLE MORE THAN NORMAL CTL FORCE TO MOVE THE CTLS. MANUAL GEAR EXTENSION WAS SIMPLE ENOUGH THAT THEY HAD AMPLE TIME TO THINK ABOUT THEIR PROBS. THE 'A' SYS HAD FAILED BUT, THE LOWER CAPACITY 'B' SYS WORKED WELL. THEY HAD TO BE TOWED OFF OF THE RWY UPON LNDG AS THEY LOST THEIR NOSEWHEEL STEERING WITH THE LOSS OF THE 'A' HYD SYS.

Data retrieved from NASA's ASRS site as of July 2007 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.