Narrative:

While taxiing from runway 22R at ord to the gate after landing, the second officer announced that the hydraulic quantity was decreasing. We were turning off the outer taxiway and lining up for a straight shot into gate. Emergency immediate action items were completed. Considering the very short distance to the gate and the information that the brake pressure was holding, I chose to park at the gate. A short distance from the gate the auxiliary pump was started and again the brake pressure was still reported as ok. All of this was over a period of 30-40 seconds. Later it was determined that there was some confusion as to how much brake pressure we really had and that we were almost down to the 1000 psi accumulator pressure. As a crew we consulted large transport flight manager at ord flight operations and the situation was discussed at length. He determined that the second officer needed more training to bring her knowledge of the hydraulic system up to PAR. A firm landing had been made, but the hydraulic leak was unrelated to any hard landing situation according to maintenance.

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Original NASA ASRS Text

Title: ACR LGT EXPERIENCES LOSS OF HYDRAULIC FLUID AND PIC EXPRESSES HIS CONCERN FOR BRAKING CAPABILITIES AS HE TAXIES ACFT INTO GATE.

Narrative: WHILE TAXIING FROM RWY 22R AT ORD TO THE GATE AFTER LNDG, THE S/O ANNOUNCED THAT THE HYD QUANTITY WAS DECREASING. WE WERE TURNING OFF THE OUTER TXWY AND LINING UP FOR A STRAIGHT SHOT INTO GATE. EMER IMMEDIATE ACTION ITEMS WERE COMPLETED. CONSIDERING THE VERY SHORT DISTANCE TO THE GATE AND THE INFO THAT THE BRAKE PRESSURE WAS HOLDING, I CHOSE TO PARK AT THE GATE. A SHORT DISTANCE FROM THE GATE THE AUX PUMP WAS STARTED AND AGAIN THE BRAKE PRESSURE WAS STILL RPTED AS OK. ALL OF THIS WAS OVER A PERIOD OF 30-40 SECS. LATER IT WAS DETERMINED THAT THERE WAS SOME CONFUSION AS TO HOW MUCH BRAKE PRESSURE WE REALLY HAD AND THAT WE WERE ALMOST DOWN TO THE 1000 PSI ACCUMULATOR PRESSURE. AS A CREW WE CONSULTED LGT FLT MGR AT ORD FLT OPS AND THE SITUATION WAS DISCUSSED AT LENGTH. HE DETERMINED THAT THE S/O NEEDED MORE TRNING TO BRING HER KNOWLEDGE OF THE HYD SYS UP TO PAR. A FIRM LNDG HAD BEEN MADE, BUT THE HYD LEAK WAS UNRELATED TO ANY HARD LNDG SITUATION ACCORDING TO MAINT.

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.