B777 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 200; Flight Crew Total 8310; Flight Crew Type 701
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Returned To Departure Airport; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Landed in Emergency Condition; General Maintenance Action
Weather; Aircraft
Level at FL340 enroute we got a PACK L EICAS. Completed the checklist and did not regain the pack. The Captain called Dispatch on the SATCOM to discuss ETOPS crossing limitations and ramifications and gave me the aircraft and radios as PF. Due to turbulence at FL340 and an oceanic crossing clearance at FL380; I asked for and received clearance to climb to FL380. At FL360 we got a BLEED R EICAS and other associated right bleed system EICAS. We completed all checklist procedures. The cabin pressure started climbing; peaking at around 6900 ft. I immediately notified ATC and requested a turn back and an immediate descent to 10000 ft MSL. The Captain and Dispatcher agreed that the departure airport would be our diversion airport. We never exceeded cabin limits and the cabin masks did not deploy. We flew an uneventful 22K pounds overweight landing as we did not see a reason to dump fuel for such a small overweight overage. We did run the Overweight Landing Unannunciated checklist. Maintenance determined that a gasket in the right bleed piping had ruptured causing the right bleed system to automatically shutdown. One other note was that we departed with an MEL on the wing anti-ice system. There was a procedure to be able to use wing anti-ice with an MEL checklist. We picked up about ¼ inch of ice on the windshield wiper nuts in the descent with an associated WING ICE EICAS but there was nothing we could do about it due to the PACK L and BLEED R malfunctions we were handling which negated the steps required in the MEL procedure. Another note is I believe that the left pack had a history of overheating and pack trips.
Shortly after reaching FL340; the left pack tripped off with associated EICAS msg. Ran the pack trip checklist; but were unable to regain use of left pack. During phone conversation Dispatch and Maintenance; the right bleed tripped off; along with the right pack tripping off. Accomplished respective checklists for the right side pressurization issues without regaining either of the items. Unable to control the cabin pressure. ATC granted an expeditious descent with a turn toward our departure airport.
B777 crew described a sequence of events when the PACK L trip would not reset followed by the BLEED R EICAS due to a bleed duct gasket failure. An expeditious descent was begun while returning to the departure airport.