B777 flight crew on north atlantic has idg failure and aircraft is reconfigured by starting APU. A s...

Narrative:

While at cruise FL340 mach .84 I noticed we had an EICAS message 'electrical generator drive left.' we followed the checklist and disconnected the left generator and started the APU. The electrical synoptic showed the system worked as it should with the APU now carrying the load of the left main bus. We spoke with dispatch and maintenance. We called up the captain from her break and briefed her thoroughly. The electrical issue was well under control but fuel was now a factor since the APU carried penalties. Dispatch agreed with our decision to proceed to ZZZ. We were also stuck at FL340 due to opposite direction flow of airplanes. We asked for FL360 but were denied. Later; within 2 hours of 'ho' the first re-dispatch message received was unacceptable due to not enough fuel at point 'ho.' a second re-dispatch message was acceptable. We constantly checked ZZZ and ZZZ1 WX since ZZZ visibility was at the time 1 3/4 mi. ZZZ1 was above 5 mi visibility. As we passed the 50W point; we got cleared direct well beyond 'ho' and at FL360 then FL380. The fuel was now less of a concern since we now showed landing with approximately 20K pounds. A later ATIS showed visibility down to 1/2 mi but the direct routing made things better. Since the second earlier re-dispatch was accepted and no noticeable changes took place; the direct routing and clearance to climb to FL360 and shortly thereafter FL380 made the situation seem even better even though the ZZZ ATIS visibility was down to 1/2 mi. Having already accepted the second re-dispatch and more direct routing (not over 'ho' -- the re-dispatch point) made us less concerned with 'ho' and more focused on the required landing fuel. At the time we got direct routing beyond 'ho;' we had received and accepted the re-dispatch and was on schedule to have the new (second re-dispatch) fuel over 'ho.' the direct routing and clearance to high altitudes improved our situation. We eventually landed at ZZZ with plenty of fuel (over 20K pounds). We were constantly getting WX updates for ZZZ; ZZZ1; and ZZZ2. We also keep a close watch on ZZZ estimated landing fuel. We never declared an emergency or 'minimum fuel.'

Original NASA ASRS Text

Title: B777 FLT CREW ON NORTH ATLANTIC HAS IDG FAILURE AND ACFT IS RECONFIGURED BY STARTING APU. A SECOND REDISPATCH POINT BECOMES NECESSARY DUE TO APU FUEL USAGE AND IS OVERLOOKED BY FLT CREW.

Narrative: WHILE AT CRUISE FL340 MACH .84 I NOTICED WE HAD AN EICAS MESSAGE 'ELECTRICAL GENERATOR DRIVE L.' WE FOLLOWED THE CHKLIST AND DISCONNECTED THE L GENERATOR AND STARTED THE APU. THE ELECTRICAL SYNOPTIC SHOWED THE SYS WORKED AS IT SHOULD WITH THE APU NOW CARRYING THE LOAD OF THE L MAIN BUS. WE SPOKE WITH DISPATCH AND MAINT. WE CALLED UP THE CAPT FROM HER BREAK AND BRIEFED HER THOROUGHLY. THE ELECTRICAL ISSUE WAS WELL UNDER CTL BUT FUEL WAS NOW A FACTOR SINCE THE APU CARRIED PENALTIES. DISPATCH AGREED WITH OUR DECISION TO PROCEED TO ZZZ. WE WERE ALSO STUCK AT FL340 DUE TO OPPOSITE DIRECTION FLOW OF AIRPLANES. WE ASKED FOR FL360 BUT WERE DENIED. LATER; WITHIN 2 HRS OF 'HO' THE FIRST RE-DISPATCH MESSAGE RECEIVED WAS UNACCEPTABLE DUE TO NOT ENOUGH FUEL AT POINT 'HO.' A SECOND RE-DISPATCH MESSAGE WAS ACCEPTABLE. WE CONSTANTLY CHKED ZZZ AND ZZZ1 WX SINCE ZZZ VISIBILITY WAS AT THE TIME 1 3/4 MI. ZZZ1 WAS ABOVE 5 MI VISIBILITY. AS WE PASSED THE 50W POINT; WE GOT CLRED DIRECT WELL BEYOND 'HO' AND AT FL360 THEN FL380. THE FUEL WAS NOW LESS OF A CONCERN SINCE WE NOW SHOWED LNDG WITH APPROX 20K LBS. A LATER ATIS SHOWED VISIBILITY DOWN TO 1/2 MI BUT THE DIRECT ROUTING MADE THINGS BETTER. SINCE THE SECOND EARLIER RE-DISPATCH WAS ACCEPTED AND NO NOTICEABLE CHANGES TOOK PLACE; THE DIRECT ROUTING AND CLRNC TO CLB TO FL360 AND SHORTLY THEREAFTER FL380 MADE THE SITUATION SEEM EVEN BETTER EVEN THOUGH THE ZZZ ATIS VISIBILITY WAS DOWN TO 1/2 MI. HAVING ALREADY ACCEPTED THE SECOND RE-DISPATCH AND MORE DIRECT ROUTING (NOT OVER 'HO' -- THE RE-DISPATCH POINT) MADE US LESS CONCERNED WITH 'HO' AND MORE FOCUSED ON THE REQUIRED LNDG FUEL. AT THE TIME WE GOT DIRECT ROUTING BEYOND 'HO;' WE HAD RECEIVED AND ACCEPTED THE RE-DISPATCH AND WAS ON SCHEDULE TO HAVE THE NEW (SECOND RE-DISPATCH) FUEL OVER 'HO.' THE DIRECT ROUTING AND CLRNC TO HIGH ALTS IMPROVED OUR SITUATION. WE EVENTUALLY LANDED AT ZZZ WITH PLENTY OF FUEL (OVER 20K LBS). WE WERE CONSTANTLY GETTING WX UPDATES FOR ZZZ; ZZZ1; AND ZZZ2. WE ALSO KEEP A CLOSE WATCH ON ZZZ ESTIMATED LNDG FUEL. WE NEVER DECLARED AN EMER OR 'MINIMUM FUEL.'

Data retrieved from NASA's ASRS site as of May 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.

Attributes
ACN	789911
Time
Date	200806
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 34000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : relief pilot
Experience	flight time last 90 days : 240 flight time total : 14500 flight time type : 5440
ASRS Report	789911
Events
Anomaly	aircraft equipment problem : less severe non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : eicas other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

B777 flight crew on north atlantic has idg failure and aircraft is reconfigured by starting APU. A second redispatch point becomes necessary due to APU fuel usage and is overlooked by flight crew.