A B767-300ER dumped fuel and diverted to another airport when the flight crew responded to a right A...

Attributes
ACN	934860
Time
Date	201102
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZZ.ARTCC
State Reference	FO
Aircraft 1
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Electrical Distribution
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Relief Pilot
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

Just prior to the nat; I got a 'right AC bus off' light illuminated on the EICAS. This was the 4th write up in 5 days. I turned around and started back to our departure airport but dispatch said zzzfo would be a better divert field. At this time; I informed shannon we were dumping 42K pounds of fuel; which took about 15 minutes; after which I declared an emergency with control. Ops wanted me to hold and burn down to max landing weight but; in the interest of safety; I did not want to hold for an hour or two with a compromised electrical system.we made an overweight landing at 329.1K. Great cockpit CRM and excellent cabin CRM. The aircraft was originally loaded with 142K of fuel for a longer flight so I had an extra 42K of fuel on takeoff.

Original NASA ASRS Text

Title: A B767-300ER dumped fuel and diverted to another airport when the Flight Crew responded to a R AC BUS OFF EICAS message as they approached the North Atlantic Tracks Westbound.

Narrative: Just prior to the NAT; I got a 'R AC BUS OFF' light illuminated on the EICAS. This was the 4th write up in 5 days. I turned around and started back to our departure airport but dispatch said ZZZFO would be a better divert field. At this time; I informed Shannon we were dumping 42K pounds of fuel; which took about 15 minutes; after which I declared an emergency with Control. Ops wanted me to hold and burn down to max landing weight but; in the interest of safety; I did not want to hold for an hour or two with a compromised electrical system.We made an overweight landing at 329.1K. Great cockpit CRM and excellent cabin CRM. The aircraft was originally loaded with 142K of fuel for a longer flight so I had an extra 42K of fuel on takeoff.

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.

A B767-300ER dumped fuel and diverted to another airport when the flight crew responded to a right AC bus off EICAS message as they approached the north atlantic tracks westbound.