Narrative:

After a hard landing on 22L at ord, we cleared the runway. I called ramp control for our gate, then noticed our hydraulic fluid was at 5 gals and system pressure was 0. I informed the captain and he asked if we had brake pressure. I said yes. Then I asked if he wanted me to move the hydraulic system selector to abnormal and he said yes. I did, and turned the engine hydraulic pumps to bypass (the immediate action items of our emergency procedure). The auxiliary pump was already off. The captain asked if brake pressure was still good. It had dropped, I told him it was low--just below 1000'. The first officer and I asked the captain how the brakes were. He said they felt ok. I asked if he wanted me to try turning the auxiliary pump on to get some pressure. He said yes, so I tried that and no pressure was gained, so the pump was turned back off. The fluid stayed at 5 gals. We should not have tried that because we had not isolated the leak--we could have lost all fluid. The gate was directly in front of us by this time and the captain elected to continue very slowly to park. The first officer and I again inquired about brakes and the captain felt they were ok. We pulled into the gate and parked west/O incident. Ramp control reported to us that fluid was leaking from the left main gear as we were pulling up to the gate. We called maintenance at the gate, shut down, went outside to look at the leak. The captain reported the events to the company and the fleet manager reviewed them with us. He wondered why no one was concerned about nose wheel steering. We said the captain hadn't indicated a problem there and we had slight and few turns. Maintenance discovered the leak was a brake line, unrelated to the hard landing. We should have stopped the aircraft to assess our situation and gotten towed in. Supplemental information from acn 146093: as we turned off high speed and crossed 27R and I went to do my cleanup after landing procedure. I noticed the flaps did not retract, nor did the stabilizer trim move to the normal 2 degrees. At the same time, second officer stated we had lost hydraulic quantity. After shutdown and investigation, it was found a brake line fitting had cracked and broken causing a massive hydraulic leak that dumped almost all fluid overboard. On investigation re: how we could have hydraulic pressure with such a fluid loss, it became evident the second officer misinterpreted accumulator pressure for hydraulic pressure. It was fortunate that the gate was so close to the runway, as it appears during the short taxi in there was only accumulator pressure for steering and brakes. Of course there was always the emergency air bottle but was never needed. After the investigation the company removed the second officer from continuing the flight and she was sent for further training. The captain and I continued the flight with a new second officer. The incident caused no damage or even a close call, but everyone learned a lesson here.

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Original NASA ASRS Text

Title: ACR HVT CONTINUES TO GATE AFTER LNDG DESPITE LOSS OF HYDRAULIC PRESSURE AND QUANTITY.

Narrative: AFTER A HARD LNDG ON 22L AT ORD, WE CLRED THE RWY. I CALLED RAMP CTL FOR OUR GATE, THEN NOTICED OUR HYD FLUID WAS AT 5 GALS AND SYS PRESSURE WAS 0. I INFORMED THE CAPT AND HE ASKED IF WE HAD BRAKE PRESSURE. I SAID YES. THEN I ASKED IF HE WANTED ME TO MOVE THE HYD SYS SELECTOR TO ABNORMAL AND HE SAID YES. I DID, AND TURNED THE ENG HYD PUMPS TO BYPASS (THE IMMEDIATE ACTION ITEMS OF OUR EMER PROC). THE AUX PUMP WAS ALREADY OFF. THE CAPT ASKED IF BRAKE PRESSURE WAS STILL GOOD. IT HAD DROPPED, I TOLD HIM IT WAS LOW--JUST BELOW 1000'. THE F/O AND I ASKED THE CAPT HOW THE BRAKES WERE. HE SAID THEY FELT OK. I ASKED IF HE WANTED ME TO TRY TURNING THE AUX PUMP ON TO GET SOME PRESSURE. HE SAID YES, SO I TRIED THAT AND NO PRESSURE WAS GAINED, SO THE PUMP WAS TURNED BACK OFF. THE FLUID STAYED AT 5 GALS. WE SHOULD NOT HAVE TRIED THAT BECAUSE WE HAD NOT ISOLATED THE LEAK--WE COULD HAVE LOST ALL FLUID. THE GATE WAS DIRECTLY IN FRONT OF US BY THIS TIME AND THE CAPT ELECTED TO CONTINUE VERY SLOWLY TO PARK. THE F/O AND I AGAIN INQUIRED ABOUT BRAKES AND THE CAPT FELT THEY WERE OK. WE PULLED INTO THE GATE AND PARKED W/O INCIDENT. RAMP CTL RPTED TO US THAT FLUID WAS LEAKING FROM THE LEFT MAIN GEAR AS WE WERE PULLING UP TO THE GATE. WE CALLED MAINT AT THE GATE, SHUT DOWN, WENT OUTSIDE TO LOOK AT THE LEAK. THE CAPT RPTED THE EVENTS TO THE COMPANY AND THE FLEET MGR REVIEWED THEM WITH US. HE WONDERED WHY NO ONE WAS CONCERNED ABOUT NOSE WHEEL STEERING. WE SAID THE CAPT HADN'T INDICATED A PROB THERE AND WE HAD SLIGHT AND FEW TURNS. MAINT DISCOVERED THE LEAK WAS A BRAKE LINE, UNRELATED TO THE HARD LNDG. WE SHOULD HAVE STOPPED THE ACFT TO ASSESS OUR SITUATION AND GOTTEN TOWED IN. SUPPLEMENTAL INFO FROM ACN 146093: AS WE TURNED OFF HIGH SPD AND CROSSED 27R AND I WENT TO DO MY CLEANUP AFTER LNDG PROC. I NOTICED THE FLAPS DID NOT RETRACT, NOR DID THE STAB TRIM MOVE TO THE NORMAL 2 DEGS. AT THE SAME TIME, S/O STATED WE HAD LOST HYD QUANTITY. AFTER SHUTDOWN AND INVESTIGATION, IT WAS FOUND A BRAKE LINE FITTING HAD CRACKED AND BROKEN CAUSING A MASSIVE HYD LEAK THAT DUMPED ALMOST ALL FLUID OVERBOARD. ON INVESTIGATION RE: HOW WE COULD HAVE HYD PRESSURE WITH SUCH A FLUID LOSS, IT BECAME EVIDENT THE S/O MISINTERPRETED ACCUMULATOR PRESSURE FOR HYD PRESSURE. IT WAS FORTUNATE THAT THE GATE WAS SO CLOSE TO THE RWY, AS IT APPEARS DURING THE SHORT TAXI IN THERE WAS ONLY ACCUMULATOR PRESSURE FOR STEERING AND BRAKES. OF COURSE THERE WAS ALWAYS THE EMER AIR BOTTLE BUT WAS NEVER NEEDED. AFTER THE INVESTIGATION THE COMPANY REMOVED THE S/O FROM CONTINUING THE FLT AND SHE WAS SENT FOR FURTHER TRNING. THE CAPT AND I CONTINUED THE FLT WITH A NEW S/O. THE INCIDENT CAUSED NO DAMAGE OR EVEN A CLOSE CALL, BUT EVERYONE LEARNED A LESSON HERE.

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.