Narrative:

While en route from jfk to london luton (eggw) on track (nat) at approximately 30 west, a caution message on EICAS 'hydraulic 2 low pressure' came on. Investigation revealed an almost complete loss of #2 hydraulic system fluid. System pressure was falling below 1800 psi. The abnormal checklist was performed. At that time we (the crew) noted an increase in the remaining fluid temperature. At that time, I felt that the engine driven pump was overheating due to the lack of fluid. Based on previous experience with this condition, I decided to secure the #2 engine to prevent further damage to the pump and related system. WX was good en route and at alternate shannon. Shanwick ATC was advised of our situation. Clearance to descend to FL280 (single engine cruising altitude for our weight and temperature) was requested and granted. Diversion to nearest suitable airport, shannon, was also requested and granted. Shanwick asked us if we wanted to declare an emergency. I replied 'affirmative.' the flight to shannon was completed on single engine without any further problems. Postflt revealed a ruptured pipe in the rear bay. A call to my chief pilot followed. He expressed concern at my willingness to declare an emergency for the above event. I stand by my decision. The declaration of the emergency alerted all parties involved in case the situation got worse. No ATC clrncs were violated, all actions were coordinated with ATC. I felt that the declaration of an emergency added a level of safety toward the completion of our flight.

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Original NASA ASRS Text

Title: AN MDT CREW ENRTE JFK TO EGGW (LONDON) EXPERIENCED AN ENG DRIVEN HYD PUMP FAILURE, REQUIRING ENG SHUTDOWN AND A DIVERSION TO THEIR ALTERNATE.

Narrative: WHILE ENRTE FROM JFK TO LONDON LUTON (EGGW) ON TRACK (NAT) AT APPROX 30 W, A CAUTION MESSAGE ON EICAS 'HYD 2 LOW PRESSURE' CAME ON. INVESTIGATION REVEALED AN ALMOST COMPLETE LOSS OF #2 HYD SYS FLUID. SYS PRESSURE WAS FALLING BELOW 1800 PSI. THE ABNORMAL CHKLIST WAS PERFORMED. AT THAT TIME WE (THE CREW) NOTED AN INCREASE IN THE REMAINING FLUID TEMP. AT THAT TIME, I FELT THAT THE ENG DRIVEN PUMP WAS OVERHEATING DUE TO THE LACK OF FLUID. BASED ON PREVIOUS EXPERIENCE WITH THIS CONDITION, I DECIDED TO SECURE THE #2 ENG TO PREVENT FURTHER DAMAGE TO THE PUMP AND RELATED SYS. WX WAS GOOD ENRTE AND AT ALTERNATE SHANNON. SHANWICK ATC WAS ADVISED OF OUR SIT. CLRNC TO DSND TO FL280 (SINGLE ENG CRUISING ALT FOR OUR WT AND TEMP) WAS REQUESTED AND GRANTED. DIVERSION TO NEAREST SUITABLE ARPT, SHANNON, WAS ALSO REQUESTED AND GRANTED. SHANWICK ASKED US IF WE WANTED TO DECLARE AN EMER. I REPLIED 'AFFIRMATIVE.' THE FLT TO SHANNON WAS COMPLETED ON SINGLE ENG WITHOUT ANY FURTHER PROBS. POSTFLT REVEALED A RUPTURED PIPE IN THE REAR BAY. A CALL TO MY CHIEF PLT FOLLOWED. HE EXPRESSED CONCERN AT MY WILLINGNESS TO DECLARE AN EMER FOR THE ABOVE EVENT. I STAND BY MY DECISION. THE DECLARATION OF THE EMER ALERTED ALL PARTIES INVOLVED IN CASE THE SIT GOT WORSE. NO ATC CLRNCS WERE VIOLATED, ALL ACTIONS WERE COORDINATED WITH ATC. I FELT THAT THE DECLARATION OF AN EMER ADDED A LEVEL OF SAFETY TOWARD THE COMPLETION OF OUR FLT.

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.