Narrative:

While at FL290, en route from omaha, nb to chicago, il, I noticed the system a hydraulic quantity at 2.6 gals (normal is 3.5 gals). I topped the gauge with my finger to see if the gauge was stuck and the quantity dropped to 2.0 gals and remained there the remainder of the flight. While discussing this with the captain, a muffled sound came from the rear of the aircraft. I turned to look at the panel and noticed the system a hydraulic lights (2) were illuminated (psi below 1200) and the pressure indicate 1700 psi (accumulator pressure only). The proper checklists were called for by the captain and accomplished as the flight progressed. We were close to des moines, ia and considered diverting there, but the WX was 700' overcast with snow. After discussing the situation with company dispatch and concurrence with the captain, it was decided to continue to chicago where the WX was better (900'-1000' broken). The flaps were electrically lowered using the standby system and the gear was manually lowered, according to checklist procedures. We stopped on the runway and were towed to parking with the passenger on board. There were no injuries or damage to the aircraft. After gate arrival I went down to see what had caused the leak. Just above the APU in the right main gear area a hydraulic line had broken off the sump and caused the loss of system a. The crew concept training was definitely visible in this situation. Supplemental information from acn 135640: crash-fire equipment standing by at ord. When airplane stopped, gear pins inserted and aircraft towed to gate.

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Original NASA ASRS Text

Title: ACR LGT LOST HYDRAULIC SYSTEM A ENROUTE TO ORD. FLT CONTINUED AS PLANNED.

Narrative: WHILE AT FL290, ENRTE FROM OMAHA, NB TO CHICAGO, IL, I NOTICED THE SYS A HYD QUANTITY AT 2.6 GALS (NORMAL IS 3.5 GALS). I TOPPED THE GAUGE WITH MY FINGER TO SEE IF THE GAUGE WAS STUCK AND THE QUANTITY DROPPED TO 2.0 GALS AND REMAINED THERE THE REMAINDER OF THE FLT. WHILE DISCUSSING THIS WITH THE CAPT, A MUFFLED SOUND CAME FROM THE REAR OF THE ACFT. I TURNED TO LOOK AT THE PANEL AND NOTICED THE SYS A HYD LIGHTS (2) WERE ILLUMINATED (PSI BELOW 1200) AND THE PRESSURE INDICATE 1700 PSI (ACCUMULATOR PRESSURE ONLY). THE PROPER CHKLISTS WERE CALLED FOR BY THE CAPT AND ACCOMPLISHED AS THE FLT PROGRESSED. WE WERE CLOSE TO DES MOINES, IA AND CONSIDERED DIVERTING THERE, BUT THE WX WAS 700' OVCST WITH SNOW. AFTER DISCUSSING THE SITUATION WITH COMPANY DISPATCH AND CONCURRENCE WITH THE CAPT, IT WAS DECIDED TO CONTINUE TO CHICAGO WHERE THE WX WAS BETTER (900'-1000' BROKEN). THE FLAPS WERE ELECTRICALLY LOWERED USING THE STANDBY SYS AND THE GEAR WAS MANUALLY LOWERED, ACCORDING TO CHKLIST PROCS. WE STOPPED ON THE RWY AND WERE TOWED TO PARKING WITH THE PAX ON BOARD. THERE WERE NO INJURIES OR DAMAGE TO THE ACFT. AFTER GATE ARR I WENT DOWN TO SEE WHAT HAD CAUSED THE LEAK. JUST ABOVE THE APU IN THE RIGHT MAIN GEAR AREA A HYD LINE HAD BROKEN OFF THE SUMP AND CAUSED THE LOSS OF SYS A. THE CREW CONCEPT TRNING WAS DEFINITELY VISIBLE IN THIS SITUATION. SUPPLEMENTAL INFO FROM ACN 135640: CRASH-FIRE EQUIP STANDING BY AT ORD. WHEN AIRPLANE STOPPED, GEAR PINS INSERTED AND ACFT TOWED TO GATE.

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.