Narrative:

Lost all hydraulic fluid from left system of B757 excluding sum of fluid remaining in standpipe. Power xfer unit activated and left autoplt disengaged. Ran appropriate quick reference checklists. Briefed flight attendants, company, and passenger. Had flight attendants plan for a possible emergency evacuate/evacuation due to unk status of flight controls, etc, during approach and landing. Had crash fire rescue equipment personnel standing by at las and requested longest runway (runway 25R). We were able to clear runway on our own. After deplaning passenger, mechanics showed us (captain and first officer) the extent of the damage. A hydraulic line burst inside the left engine pylon area and had dripped out next to the engine's exhaust during the course of the flight. When maintenance removed the pylon's access panel, hydraulic fluid spewed all over the ramp. The flight attendants did a good job in keeping the passenger calm by being professional during a trying situation. Callback conversation with reporter revealed the following information: reporter first officer had not had any feedback on the cause of the broken hydraulic line, but the hydraulic line was in the #1 engine pylon in the filler cavity above the engine. Reporter says that, in hindsight, knowing that they had a potential bomb sitting in the engine, they would have returned to land at atl. But, procedures in their manual don't address the potential danger of a hydraulic failure -- just that if one system fails the power xfer unit will take over and power the other hydraulic system. Reporter also says that on further review, it was noted that the power xfer unit is not meant to operate for a long period of time because there is potential for overheating, and they continued on for several hours after the failure. Reporter says that they are not trained nor does their manual discuss the potential danger of their type of failure. Additionally, the time that the ptu can be expected to reasonably operate without an overheat.

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Original NASA ASRS Text

Title: ACFT EQUIP PROB. L HYD FLUID LOSS DUE TO BROKEN LINE. ACFT CONTINUED TO DEST WITH UNEVENTFUL LNDG AND DEPLANING.

Narrative: LOST ALL HYD FLUID FROM L SYS OF B757 EXCLUDING SUM OF FLUID REMAINING IN STANDPIPE. PWR XFER UNIT ACTIVATED AND L AUTOPLT DISENGAGED. RAN APPROPRIATE QUICK REF CHKLISTS. BRIEFED FLT ATTENDANTS, COMPANY, AND PAX. HAD FLT ATTENDANTS PLAN FOR A POSSIBLE EMER EVAC DUE TO UNK STATUS OF FLT CTLS, ETC, DURING APCH AND LNDG. HAD CFR PERSONNEL STANDING BY AT LAS AND REQUESTED LONGEST RWY (RWY 25R). WE WERE ABLE TO CLR RWY ON OUR OWN. AFTER DEPLANING PAX, MECHS SHOWED US (CAPT AND FO) THE EXTENT OF THE DAMAGE. A HYD LINE BURST INSIDE THE L ENG PYLON AREA AND HAD DRIPPED OUT NEXT TO THE ENG'S EXHAUST DURING THE COURSE OF THE FLT. WHEN MAINT REMOVED THE PYLON'S ACCESS PANEL, HYD FLUID SPEWED ALL OVER THE RAMP. THE FLT ATTENDANTS DID A GOOD JOB IN KEEPING THE PAX CALM BY BEING PROFESSIONAL DURING A TRYING SIT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR FO HAD NOT HAD ANY FEEDBACK ON THE CAUSE OF THE BROKEN HYD LINE, BUT THE HYD LINE WAS IN THE #1 ENG PYLON IN THE FILLER CAVITY ABOVE THE ENG. RPTR SAYS THAT, IN HINDSIGHT, KNOWING THAT THEY HAD A POTENTIAL BOMB SITTING IN THE ENG, THEY WOULD HAVE RETURNED TO LAND AT ATL. BUT, PROCS IN THEIR MANUAL DON'T ADDRESS THE POTENTIAL DANGER OF A HYD FAILURE -- JUST THAT IF ONE SYS FAILS THE PWR XFER UNIT WILL TAKE OVER AND PWR THE OTHER HYD SYS. RPTR ALSO SAYS THAT ON FURTHER REVIEW, IT WAS NOTED THAT THE PWR XFER UNIT IS NOT MEANT TO OPERATE FOR A LONG PERIOD OF TIME BECAUSE THERE IS POTENTIAL FOR OVERHEATING, AND THEY CONTINUED ON FOR SEVERAL HRS AFTER THE FAILURE. RPTR SAYS THAT THEY ARE NOT TRAINED NOR DOES THEIR MANUAL DISCUSS THE POTENTIAL DANGER OF THEIR TYPE OF FAILURE. ADDITIONALLY, THE TIME THAT THE PTU CAN BE EXPECTED TO REASONABLY OPERATE WITHOUT AN OVERHEAT.

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.