|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Locale Reference||airport : zzzz.airport|
|Altitude||msl single value : 35000|
|Controlling Facilities||artcc : zzzz.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||B757-200|
|Operating Under FAR Part||Part 121|
|Flight Phase||cruise : level|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Experience||flight time last 90 days : 100|
flight time total : 8000
flight time type : 500
|Anomaly||aircraft equipment problem : critical|
|Independent Detector||aircraft equipment other aircraft equipment : eicas|
other flight crewa
|Resolutory Action||flight crew : landed in emergency condition|
flight crew : declared emergency
I was hand flying through about 15000 ft MSL. I noticed that it was taking approximately 3 units of rudder trim to the right to keep the wings level. A quick check of the fuel revealed that the left tank was 500 pounds heavier than the right! At FL350 we received EICAS message 'left hydraulic quantity.' the quantity displayed on the status page was .19RF. Right away we notified ZZZZ that we were coming back. Continuing to destination was definitely not an option with high terrain and the airport being at 8300 ft MSL. A few mins later we received our second EICAS 'left hydraulic engine pump.' we ran the checklist for the left hydraulic quantity and it stated crew awareness for the corrective action. The second checklist had us turning off the engine driven hydraulic pump. The status page displayed message 'power xfer unit.' I slowed the aircraft down and we started a descent into ZZZZ so that we could have plenty of time to analyze the situation and run all the checklist. We also declared an emergency because the left system operates the flaps; landing gear; left thrust reverser and nosewheel steering amongst other aircraft components. Now for the interesting part: confusion! Do you run the 'left hydraulic system pressure' checklist without receiving the EICAS message? Does 'power xfer unit' in the status page indicate that it is working or not? I vaguely recalled from training that 'power xfer unit' meant that it was inoperative. We could not find it in the system manual. The left hydraulic system pressure checklist states that the ptu may or may not operate. We went into holding outside the marker and started to configure. When the flaps were between 0 and 1 degree; we received EICAS message 'trailing edge flaps disagreement' and finally 'left hydraulic system pressure.' the flaps took awhile to come down using the electrical motors. Using the checklists; we dropped the gear with no problem. Once we had the checklist completed; we began the ILS into the long runway. The first officer asked tower if we could communication directly with crash fire rescue equipment personnel to which they replied no. It would have been nice to talk directly to them versus using a middle man. It would have kept xmissions to a minimum and avoided miscoms. The aircraft was configured with flaps 20 degrees. I was surprised at how unresponsive the elevator was in the flare and used power to break the sink rate. I used left rudder and the right thrust reverser to keep the aircraft on centerline and manual braking to stop. As we approached the high speed taxiway; I slowed the aircraft to about 10-15 KTS hoping to clear the runway. We turned left and it felt as the nosewheel came hard left. I had no control taxiing; so I stopped right away. Half the aircraft was on the runway; half on the taxiway. The tower informed us that the crash fire rescue equipment personnel said our left brakes were hot. They installed a fan to cool it down. They cleared us with hand signals and left after about 20 mins. The mechanic and tow crew came out to take us back to the ramp. He asked me to drop the gear pins out the window; which I did after about 3 mins of trying to locate them! They are behind the right observer seat in a pouch.
Original NASA ASRS Text
Title: B757-200 LOST FLUID FOR THE LEFT HYD SYSTEM. EMER WAS DECLARED AND THE FLT RETURNED. NUMEROUS COMPONENTS ARE AFFECTED BY THIS HYD SYSTEM LOSS; AND THE APPROPRIATE CHECKLISTS WERE FOLLOWED BEFORE THE APCH AND LNDG.
Narrative: I WAS HAND FLYING THROUGH ABOUT 15000 FT MSL. I NOTICED THAT IT WAS TAKING APPROX 3 UNITS OF RUDDER TRIM TO THE R TO KEEP THE WINGS LEVEL. A QUICK CHK OF THE FUEL REVEALED THAT THE L TANK WAS 500 LBS HEAVIER THAN THE R! AT FL350 WE RECEIVED EICAS MESSAGE 'L HYD QUANTITY.' THE QUANTITY DISPLAYED ON THE STATUS PAGE WAS .19RF. RIGHT AWAY WE NOTIFIED ZZZZ THAT WE WERE COMING BACK. CONTINUING TO DEST WAS DEFINITELY NOT AN OPTION WITH HIGH TERRAIN AND THE ARPT BEING AT 8300 FT MSL. A FEW MINS LATER WE RECEIVED OUR SECOND EICAS 'L HYD ENG PUMP.' WE RAN THE CHKLIST FOR THE L HYD QUANTITY AND IT STATED CREW AWARENESS FOR THE CORRECTIVE ACTION. THE SECOND CHKLIST HAD US TURNING OFF THE ENG DRIVEN HYD PUMP. THE STATUS PAGE DISPLAYED MESSAGE 'PWR XFER UNIT.' I SLOWED THE ACFT DOWN AND WE STARTED A DSCNT INTO ZZZZ SO THAT WE COULD HAVE PLENTY OF TIME TO ANALYZE THE SITUATION AND RUN ALL THE CHKLIST. WE ALSO DECLARED AN EMER BECAUSE THE L SYS OPERATES THE FLAPS; LNDG GEAR; L THRUST REVERSER AND NOSEWHEEL STEERING AMONGST OTHER ACFT COMPONENTS. NOW FOR THE INTERESTING PART: CONFUSION! DO YOU RUN THE 'L HYD SYS PRESSURE' CHKLIST WITHOUT RECEIVING THE EICAS MESSAGE? DOES 'PWR XFER UNIT' IN THE STATUS PAGE INDICATE THAT IT IS WORKING OR NOT? I VAGUELY RECALLED FROM TRAINING THAT 'PWR XFER UNIT' MEANT THAT IT WAS INOP. WE COULD NOT FIND IT IN THE SYS MANUAL. THE L HYD SYS PRESSURE CHKLIST STATES THAT THE PTU MAY OR MAY NOT OPERATE. WE WENT INTO HOLDING OUTSIDE THE MARKER AND STARTED TO CONFIGURE. WHEN THE FLAPS WERE BTWN 0 AND 1 DEG; WE RECEIVED EICAS MESSAGE 'TRAILING EDGE FLAPS DISAGREEMENT' AND FINALLY 'L HYD SYS PRESSURE.' THE FLAPS TOOK AWHILE TO COME DOWN USING THE ELECTRICAL MOTORS. USING THE CHKLISTS; WE DROPPED THE GEAR WITH NO PROB. ONCE WE HAD THE CHKLIST COMPLETED; WE BEGAN THE ILS INTO THE LONG RWY. THE FO ASKED TWR IF WE COULD COM DIRECTLY WITH CFR PERSONNEL TO WHICH THEY REPLIED NO. IT WOULD HAVE BEEN NICE TO TALK DIRECTLY TO THEM VERSUS USING A MIDDLE MAN. IT WOULD HAVE KEPT XMISSIONS TO A MINIMUM AND AVOIDED MISCOMS. THE ACFT WAS CONFIGURED WITH FLAPS 20 DEGS. I WAS SURPRISED AT HOW UNRESPONSIVE THE ELEVATOR WAS IN THE FLARE AND USED PWR TO BREAK THE SINK RATE. I USED L RUDDER AND THE R THRUST REVERSER TO KEEP THE ACFT ON CTRLINE AND MANUAL BRAKING TO STOP. AS WE APCHED THE HIGH SPD TXWY; I SLOWED THE ACFT TO ABOUT 10-15 KTS HOPING TO CLR THE RWY. WE TURNED L AND IT FELT AS THE NOSEWHEEL CAME HARD L. I HAD NO CTL TAXIING; SO I STOPPED RIGHT AWAY. HALF THE ACFT WAS ON THE RWY; HALF ON THE TXWY. THE TWR INFORMED US THAT THE CFR PERSONNEL SAID OUR L BRAKES WERE HOT. THEY INSTALLED A FAN TO COOL IT DOWN. THEY CLRED US WITH HAND SIGNALS AND LEFT AFTER ABOUT 20 MINS. THE MECH AND TOW CREW CAME OUT TO TAKE US BACK TO THE RAMP. HE ASKED ME TO DROP THE GEAR PINS OUT THE WINDOW; WHICH I DID AFTER ABOUT 3 MINS OF TRYING TO LOCATE THEM! THEY ARE BEHIND THE R OBSERVER SEAT IN A POUCH.
Data retrieved from NASA's ASRS site as of January 2009 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.