B757 flight crew departing lax experienced loss of one complete hydraulic system. Returned to lax an...

Attributes
ACN	585323
Time
Date	200306
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	intersection : dinty
State Reference	CA
Altitude	msl bound lower : 0 msl bound upper : 35000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : vacating altitude cruise : level descent : approach
Route In Use	enroute : pacific
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	585323
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical non adherence : far other anomaly other
Independent Detector	atc equipment other atc equipment : hyd sys lights other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : landed in emergency condition flight crew : diverted to another airport other
Consequence	other
Factors
Maintenance	contributing factor : schedule pressure contributing factor : engineering procedure performance deficiency : non compliance with legal requirements performance deficiency : fault isolation
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft Airspace Structure Company Maintenance Human Performance
Primary Problem	Aircraft

Narrative:

After we taxied out, got a left engine hydraulic pump overheat light on. Contacted maintenance controller after turning off the pumps. He instructed us to turn off pumps and then turn them back on after cooling and check hydraulic temperature and pressure. The overheat light came back on but the hydraulic temperature and pressure were equal across the board. He felt it was a sensor problem and not a pump problem, so he ok'd to continue. After takeoff got the stabilizer trim light on. We followed the checklist. The trim seemed to operate normally. All hydraulic quantities were normal. This light stayed on when the autoplt was engaged. Approaching dinty, we got left hydraulic system pressure light and reverser light on. Checked left hydraulic quantity was 0.03 psi. We got the rudder ratio light also. No ptu xfer light or hmg was on EICAS. We called dispatch and he patched into maintenance control. They told us we were ok to continue into ETOPS airspace. At XA29Z got a call from dispatch that the maintenance controller wanted a return to lax due to supplies and maintenance not available at destination. We got clearance to return to lax at N3201 pt 2 W12850 pt 7. Following checklist for left hydraulic system pressure we knew there might be a problem with normal gear and flap extension. We lowered the gear outside of vtu and got the ptu xfer unit message and the gear disagree light on. The captain took over control of the flight and we ran the checklists for gear disagree and trailing edge flaps disagree. When we realized there may be no nosewheel steering we called maintenance and had them meet us at taxiway off runway 25R. We did not declare an emergency or issue a cabin advisory. The doa called an amber alert and the equipment met the flight. We landed slightly overweight at 205000 pounds versus 198000 pounds. We made a smooth landing with minimal sink rate. We were towed to the gate after clearing the runway.

Original NASA ASRS Text

Title: B757 FLT CREW DEPARTING LAX EXPERIENCED LOSS OF ONE COMPLETE HYD SYS. RETURNED TO LAX AND LANDED SAFELY. FLT CREW DID NOT DECLARE EMER OR PLAN FOR EMER CONTINGENCIES.

Narrative: AFTER WE TAXIED OUT, GOT A L ENG HYD PUMP OVERHEAT LIGHT ON. CONTACTED MAINT CTLR AFTER TURNING OFF THE PUMPS. HE INSTRUCTED US TO TURN OFF PUMPS AND THEN TURN THEM BACK ON AFTER COOLING AND CHK HYD TEMP AND PRESSURE. THE OVERHEAT LIGHT CAME BACK ON BUT THE HYD TEMP AND PRESSURE WERE EQUAL ACROSS THE BOARD. HE FELT IT WAS A SENSOR PROB AND NOT A PUMP PROB, SO HE OK'D TO CONTINUE. AFTER TKOF GOT THE STABILIZER TRIM LIGHT ON. WE FOLLOWED THE CHKLIST. THE TRIM SEEMED TO OPERATE NORMALLY. ALL HYD QUANTITIES WERE NORMAL. THIS LIGHT STAYED ON WHEN THE AUTOPLT WAS ENGAGED. APCHING DINTY, WE GOT L HYD SYS PRESSURE LIGHT AND REVERSER LIGHT ON. CHKED L HYD QUANTITY WAS 0.03 PSI. WE GOT THE RUDDER RATIO LIGHT ALSO. NO PTU XFER LIGHT OR HMG WAS ON EICAS. WE CALLED DISPATCH AND HE PATCHED INTO MAINT CTL. THEY TOLD US WE WERE OK TO CONTINUE INTO ETOPS AIRSPACE. AT XA29Z GOT A CALL FROM DISPATCH THAT THE MAINT CTLR WANTED A RETURN TO LAX DUE TO SUPPLIES AND MAINT NOT AVAILABLE AT DEST. WE GOT CLRNC TO RETURN TO LAX AT N3201 PT 2 W12850 PT 7. FOLLOWING CHKLIST FOR L HYD SYS PRESSURE WE KNEW THERE MIGHT BE A PROB WITH NORMAL GEAR AND FLAP EXTENSION. WE LOWERED THE GEAR OUTSIDE OF VTU AND GOT THE PTU XFER UNIT MESSAGE AND THE GEAR DISAGREE LIGHT ON. THE CAPT TOOK OVER CTL OF THE FLT AND WE RAN THE CHKLISTS FOR GEAR DISAGREE AND TRAILING EDGE FLAPS DISAGREE. WHEN WE REALIZED THERE MAY BE NO NOSEWHEEL STEERING WE CALLED MAINT AND HAD THEM MEET US AT TXWY OFF RWY 25R. WE DID NOT DECLARE AN EMER OR ISSUE A CABIN ADVISORY. THE DOA CALLED AN AMBER ALERT AND THE EQUIP MET THE FLT. WE LANDED SLIGHTLY OVERWT AT 205000 LBS VERSUS 198000 LBS. WE MADE A SMOOTH LNDG WITH MINIMAL SINK RATE. WE WERE TOWED TO THE GATE AFTER CLRING THE RWY.

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.

B757 flight crew departing lax experienced loss of one complete hydraulic system. Returned to lax and landed safely. Flight crew did not declare emergency or plan for emergency contingencies.