Narrative:

During cruise flight, flight engineer notified me of a very slow reduction of 'a' system hydraulic quantity. I immediately called for the #11 hydraulic fluid quantity decreasing checklist. The first officer was flying the aircraft and I instructed him to continue to fly the aircraft and handle communications with ATC and advise them that we might have a possible hydraulic problem and that we did not need any special assistance at this time. I also advised the first officer that I would be working with the flight engineer on the problem of 'a' system hydraulic quantity decreasing. Since 'a' system hydraulic quantity virtually stopped at 2.7 gallons and all other hydraulic systems pressures and quantities were normal and because of our position from ind, I elected to extend the landing gear hydraulically while 'a' system hydraulic pressure and quantity were stable. We consulted the gear down cruise chart before extending the landing gear, and after the landing gear was down and locked with 3 green lights, accomplished the #11 hydraulic fluid quantity decreasing checklist. At completion of the checklist 'a' system hydraulic quantity was just above 0 gallons. We then accomplished the #13 system 'a' loss checklist. Then I briefed the #1 flight attendant and passenger announcement to the passenger, then notified ATC to have 'crash fire rescue equipment' equipment at the runway upon our arrival and to communicate to company operations need for a tug unit to also be at the runway to assist towing aircraft to the gate after landing completed. Approach and landing was uneventful and aircraft came to a complete stop on centerline, runway 05L at ind, adjacent to taxiway A2. Company tug unit hooked up to aircraft and (by my request) 3 gear pins were installed in the landing gear and aircraft towed to the gate. Cause: component failure - flap drive actuator location right main landing gear well. Prevent this occurrence: more inspections on the failed component.

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Original NASA ASRS Text

Title: ACR LGT HAS 'A' SYSTEM HYD FAILURE.

Narrative: DURING CRUISE FLT, FE NOTIFIED ME OF A VERY SLOW REDUCTION OF 'A' SYSTEM HYD QUANTITY. I IMMEDIATELY CALLED FOR THE #11 HYD FLUID QUANTITY DECREASING CHKLIST. THE FO WAS FLYING THE ACFT AND I INSTRUCTED HIM TO CONTINUE TO FLY THE ACFT AND HANDLE COMS WITH ATC AND ADVISE THEM THAT WE MIGHT HAVE A POSSIBLE HYD PROBLEM AND THAT WE DID NOT NEED ANY SPECIAL ASSISTANCE AT THIS TIME. I ALSO ADVISED THE FO THAT I WOULD BE WORKING WITH THE FE ON THE PROBLEM OF 'A' SYSTEM HYD QUANTITY DECREASING. SINCE 'A' SYSTEM HYD QUANTITY VIRTUALLY STOPPED AT 2.7 GALLONS AND ALL OTHER HYD SYSTEMS PRESSURES AND QUANTITIES WERE NORMAL AND BECAUSE OF OUR POS FROM IND, I ELECTED TO EXTEND THE LNDG GEAR HYDRAULICALLY WHILE 'A' SYSTEM HYD PRESSURE AND QUANTITY WERE STABLE. WE CONSULTED THE GEAR DOWN CRUISE CHART BEFORE EXTENDING THE LNDG GEAR, AND AFTER THE LNDG GEAR WAS DOWN AND LOCKED WITH 3 GREEN LIGHTS, ACCOMPLISHED THE #11 HYD FLUID QUANTITY DECREASING CHKLIST. AT COMPLETION OF THE CHKLIST 'A' SYSTEM HYD QUANTITY WAS JUST ABOVE 0 GALLONS. WE THEN ACCOMPLISHED THE #13 SYSTEM 'A' LOSS CHKLIST. THEN I BRIEFED THE #1 FA AND PAX ANNOUNCEMENT TO THE PAX, THEN NOTIFIED ATC TO HAVE 'CFR' EQUIPMENT AT THE RWY UPON OUR ARR AND TO COMMUNICATE TO COMPANY OPERATIONS NEED FOR A TUG UNIT TO ALSO BE AT THE RWY TO ASSIST TOWING ACFT TO THE GATE AFTER LNDG COMPLETED. APCH AND LNDG WAS UNEVENTFUL AND ACFT CAME TO A COMPLETE STOP ON CENTERLINE, RWY 05L AT IND, ADJACENT TO TAXIWAY A2. COMPANY TUG UNIT HOOKED UP TO ACFT AND (BY MY REQUEST) 3 GEAR PINS WERE INSTALLED IN THE LNDG GEAR AND ACFT TOWED TO THE GATE. CAUSE: COMPONENT FAILURE - FLAP DRIVE ACTUATOR LOCATION R MAIN LNDG GEAR WELL. PREVENT THIS OCCURRENCE: MORE INSPECTIONS ON THE FAILED COMPONENT.

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.