B757-200 flight crew experiences loss of left system hydraulic quantity.

Attributes
ACN	751057
Time
Date	200708
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 36000
Aircraft 1
Controlling Facilities	artcc : zzz.artcc tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 260 flight time total : 23000 flight time type : 9000
ASRS Report	751057
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 215 flight time total : 13500 flight time type : 7000
ASRS Report	751058
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : oil qyt indicator
Resolutory Action	flight crew : landed in emergency condition flight crew : declared emergency
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

At FL360 about 3 hours into the flight and about 2 hours from landing; I checked the EICAS status page to review hydraulic quantities and noticed the left hydraulic system that had been holding around .96 had dropped to .49 and was continuing to drop in level. Followed flight handbook procedures and shut off left electric and engine driven pump and level stopped dropping and held at .42. Contacted dispatch and maintenance and decided to make a normal approach and landing at ZZZ. On final; turned pumps back on and made normal landing. Dispatch notified ATC that we were declaring an emergency and requested equipment for our landing at ZZZ. After block-in; mechanics notified a lot of hydraulic leaking from the left engine pylon area. Aircraft taken OTS and repaired.

Original NASA ASRS Text

Title: B757-200 FLT CREW EXPERIENCES LOSS OF LEFT SYSTEM HYDRAULIC QUANTITY.

Narrative: AT FL360 ABOUT 3 HRS INTO THE FLT AND ABOUT 2 HRS FROM LNDG; I CHKED THE EICAS STATUS PAGE TO REVIEW HYD QUANTITIES AND NOTICED THE L HYD SYS THAT HAD BEEN HOLDING AROUND .96 HAD DROPPED TO .49 AND WAS CONTINUING TO DROP IN LEVEL. FOLLOWED FLT HANDBOOK PROCS AND SHUT OFF L ELECTRIC AND ENG DRIVEN PUMP AND LEVEL STOPPED DROPPING AND HELD AT .42. CONTACTED DISPATCH AND MAINT AND DECIDED TO MAKE A NORMAL APCH AND LNDG AT ZZZ. ON FINAL; TURNED PUMPS BACK ON AND MADE NORMAL LNDG. DISPATCH NOTIFIED ATC THAT WE WERE DECLARING AN EMER AND REQUESTED EQUIP FOR OUR LNDG AT ZZZ. AFTER BLOCK-IN; MECHS NOTIFIED A LOT OF HYD LEAKING FROM THE L ENG PYLON AREA. ACFT TAKEN OTS AND REPAIRED.

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.