Narrative:

Upon returning from my rest break; I was informed that aircraft had just experienced a partial loss of hydraulic fluid from left system; with the EICAS message left hydraulic qty. QRH had been followed; and both left engine hydraulic pump and left electric pump had been turned off. System quantity read about 0.36RF. Called dispatch via satcom; and talked about situation with dispatcher; who also tied me into maintenance. We agreed that declaring an emergency would be the prudent course; so upon termination of satcom; dispatch called our destination tower and I informed ARTCC of our situation and required emergency information. First officer was flying the aircraft; and continued for the duration of flight. I called purser to the cockpit to give her the test information. During this time the relief officer helped coordinate with destination maintenance and gate control; plus had QRH at the ready. Gave passengers a PA; letting them know of the emergency condition and that crash and rescue vehicles would be responding to our landing. We received radar vectors to a straight in approach. First officer made an excellent approach and landing. Since we did have a crosswind from the southwest (winds 230/14 or 15 KTS) we decided to turn on both left systems pumps prior to landing to ensure maximum flight control utilization. After touchdown and rollout; I took control and taxied aircraft to a runway pad; and requested that airport rescue and fire fighting personnel look over left side of wing and aircraft and let me know of any leaks. We also turned off both left pumps and completed rest of landing checks. Airport rescue and fire fighting personnel observed just minor leak on left engine nacelle so we then terminated emergency; and taxied to gate without further incident. Note of interest: since placed into our mailboxes earlier this week a new 757/767 QRH; we had a chance to compare procedures for our situation. The current QRH had us turn off the affected primary and demand pumps; and gave us the ability to turn them back on for approach and landing; at captain's discretion. The new QRH has left; C; right hydraulic quantity as crew awareness only; so in theory; crew could watch quantity go to zero then go to loss of system procedure. However; by allowing a total system quantity loss prior to shutting off affected pump(s) cavitation and damage to and/or destruction of pump(s) may occur; which would also prevent utilization of pumps(s) for landing. This procedure in the new QRH should be reexamined.

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Original NASA ASRS Text

Title: A B767-300 had a partial loss of left hydraulic system fluid. An emergency was declared followed by a normal approach.

Narrative: Upon returning from my rest break; I was informed that aircraft had just experienced a partial loss of hydraulic fluid from left system; with the EICAS message L HYD QTY. QRH had been followed; and both left engine hydraulic pump and left electric pump had been turned off. System quantity read about 0.36RF. Called dispatch via SATCOM; and talked about situation with Dispatcher; who also tied me into Maintenance. We agreed that declaring an emergency would be the prudent course; so upon termination of SATCOM; dispatch called our destination Tower and I informed ARTCC of our situation and required emergency information. First Officer was flying the aircraft; and continued for the duration of flight. I called Purser to the cockpit to give her the TEST information. During this time the Relief Officer helped coordinate with destination maintenance and gate control; plus had QRH at the ready. Gave passengers a PA; letting them know of the emergency condition and that crash and rescue vehicles would be responding to our landing. We received radar vectors to a straight in approach. First Officer made an excellent approach and landing. Since we did have a crosswind from the Southwest (winds 230/14 or 15 KTS) we decided to turn on both left systems pumps prior to landing to ensure maximum flight control utilization. After touchdown and rollout; I took control and taxied aircraft to a Runway pad; and requested that Airport rescue and fire fighting personnel look over left side of wing and aircraft and let me know of any leaks. We also turned off both left pumps and completed rest of landing checks. Airport rescue and fire fighting personnel observed just minor leak on left engine nacelle so we then terminated emergency; and taxied to gate without further incident. Note of interest: Since placed into our mailboxes earlier this week a new 757/767 QRH; we had a chance to compare procedures for our situation. The current QRH had us turn off the affected primary and demand pumps; and gave us the ability to turn them back on for approach and landing; at Captain's discretion. The new QRH has L; C; R hydraulic quantity as crew awareness only; so in theory; crew could watch quantity go to zero then go to Loss of System procedure. However; by allowing a total system quantity loss prior to shutting off affected pump(s) cavitation and damage to and/or destruction of pump(s) may occur; which would also prevent utilization of pumps(s) for landing. This procedure in the new QRH should be reexamined.

Data retrieved from NASA's ASRS site as of April 2012 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.